From 04bbbdff2219a912ae8aa1acab464fcf0ffd6fb4 Mon Sep 17 00:00:00 2001
From: haseeb-ahmad <engg.haseeb@gmail.com>
Date: Fri, 8 Dec 2023 20:09:15 +0500
Subject: [PATCH] CDB-8052 CDB-8050 Upgraded to ruby 3.1.2 (#305)

* CPD-8050: Update to ruby 3.1.2

* Fixed s3 client keyword argument error

* CPD-8050: volume_id fix for instance hash

* CPD-8052: moonhot status output fix

* CPD-8050: rubocop fixes

* CPD-8050: Fixed rubocop Naming/MethodParameterName.

---------

Co-authored-by: rutuja810 <rutuja.dhimate@acquia.com>
Co-authored-by: Kaushik Sirineni <kaushik.sirineni@acquia.com>
---
 .rubocop.yml                                  |  6 +-
 .ruby-version                                 |  2 +-
 .travis.yml                                   | 23 -----
 Gemfile                                       |  6 +-
 Rakefile                                      |  4 +-
 bin/moonshot                                  |  5 +-
 lib/moonshot.rb                               |  6 ++
 lib/moonshot/account_context.rb               |  4 +-
 lib/moonshot/always_use_default_source.rb     |  8 +-
 lib/moonshot/artifact_repository/s3_bucket.rb |  2 +-
 .../s3_bucket_via_github_releases.rb          | 14 +--
 lib/moonshot/ask_user_source.rb               | 18 ++--
 .../build_mechanism/github_release.rb         | 11 ++-
 lib/moonshot/build_mechanism/script.rb        | 15 ++--
 lib/moonshot/build_mechanism/travis_deploy.rb | 10 +--
 lib/moonshot/build_mechanism/version_proxy.rb |  8 +-
 lib/moonshot/change_set.rb                    | 28 +++---
 lib/moonshot/command.rb                       |  6 +-
 lib/moonshot/command_line.rb                  | 21 +++--
 lib/moonshot/command_line_dispatcher.rb       | 12 ++-
 lib/moonshot/commands/console.rb              |  2 +
 lib/moonshot/commands/delete.rb               |  4 +-
 lib/moonshot/commands/deploy.rb               |  2 +
 lib/moonshot/commands/doctor.rb               |  2 +
 lib/moonshot/commands/generate_template.rb    |  2 +
 lib/moonshot/commands/interactive_command.rb  |  2 +
 lib/moonshot/commands/list.rb                 |  2 +
 lib/moonshot/commands/new.rb                  | 53 ++++++------
 lib/moonshot/commands/parameter_arguments.rb  |  9 +-
 lib/moonshot/commands/parent_stack_option.rb  |  2 +
 lib/moonshot/commands/push.rb                 |  2 +
 .../commands/show_all_events_option.rb        |  2 +
 lib/moonshot/commands/status.rb               |  2 +
 lib/moonshot/commands/tag_arguments.rb        |  6 +-
 lib/moonshot/commands/update.rb               |  6 +-
 lib/moonshot/commands/version.rb              |  2 +
 lib/moonshot/config.rb                        |  1 +
 lib/moonshot/controller.rb                    | 28 +++---
 lib/moonshot/controller_config.rb             | 34 ++------
 lib/moonshot/creds_helper.rb                  |  2 +
 .../deployment_mechanism/code_deploy.rb       | 85 ++++++++++---------
 lib/moonshot/doctor_helper.rb                 | 29 +++----
 lib/moonshot/dynamic_template.rb              |  3 +
 lib/moonshot/interactive_logger_proxy.rb      |  8 +-
 lib/moonshot/parameter_collection.rb          |  3 +
 lib/moonshot/parent_stack_parameter_loader.rb | 10 ++-
 lib/moonshot/resources.rb                     |  2 +
 lib/moonshot/resources_helper.rb              |  6 +-
 lib/moonshot/shell.rb                         | 18 ++--
 lib/moonshot/ssh_command.rb                   |  2 +
 lib/moonshot/ssh_command_builder.rb           |  4 +-
 lib/moonshot/ssh_config.rb                    |  6 +-
 lib/moonshot/ssh_fork_executor.rb             |  2 +
 lib/moonshot/ssh_target_selector.rb           |  6 +-
 lib/moonshot/stack.rb                         | 84 +++++++++---------
 lib/moonshot/stack_asg_printer.rb             | 13 +--
 lib/moonshot/stack_config.rb                  |  5 +-
 lib/moonshot/stack_events_poller.rb           |  4 +-
 lib/moonshot/stack_list_printer.rb            |  2 +
 lib/moonshot/stack_lister.rb                  | 10 ++-
 lib/moonshot/stack_output_printer.rb          |  2 +
 lib/moonshot/stack_parameter.rb               | 14 ++-
 lib/moonshot/stack_parameter_printer.rb       |  4 +-
 lib/moonshot/stack_template.rb                |  2 +
 lib/moonshot/task.rb                          |  3 +
 lib/moonshot/tools/asg_rollout.rb             | 30 ++++---
 lib/moonshot/tools/asg_rollout/asg.rb         | 38 ++++-----
 .../tools/asg_rollout/asg_instance.rb         |  2 +
 .../asg_rollout/hook_exec_environment.rb      |  2 +
 .../tools/asg_rollout/instance_health.rb      |  2 +
 lib/moonshot/tools/asg_rollout_config.rb      |  2 +
 lib/moonshot/unicode_table.rb                 |  8 +-
 lib/moonshot/yaml_stack_template.rb           |  2 +
 lib/plugins/backup.rb                         | 71 ++++++++--------
 lib/plugins/code_deploy_setup.rb              |  6 +-
 lib/plugins/dynamic_template.rb               | 10 ++-
 lib/plugins/encrypted_parameters.rb           |  6 +-
 lib/plugins/encrypted_parameters/kms_key.rb   | 17 ++--
 .../parameter_encrypter.rb                    |  2 +
 lib/plugins/rotate_asg_instances/asg.rb       | 37 ++++----
 lib/plugins/rotate_asg_instances/ssh.rb       |  3 +
 moonshot.gemspec                              |  6 +-
 sample/Gemfile                                |  2 +
 spec/moonshot/commands/build_spec.rb          |  6 +-
 spec/moonshot/shell_spec.rb                   |  2 +-
 spec/moonshot/stack_spec.rb                   |  2 +-
 86 files changed, 532 insertions(+), 425 deletions(-)
 delete mode 100644 .travis.yml

diff --git a/.rubocop.yml b/.rubocop.yml
index 3cf76d77..e130f0d8 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,6 +1,6 @@
 ---
 AllCops:
-  TargetRubyVersion: 2.2
+  TargetRubyVersion: 3.1.2
   Exclude:
     - '.gemspec'
     - 'vendor/**/*'
@@ -20,3 +20,7 @@ Metrics/ClassLength:
   Max: 130
 Style/Documentation:
   Enabled: false
+Naming/HeredocDelimiterNaming:
+  Enabled: false
+Style/HashSyntax:
+  Enabled: false
diff --git a/.ruby-version b/.ruby-version
index 743af5e1..ef538c28 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-2.6.8
+3.1.2
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 28a79308..00000000
--- a/.travis.yml
+++ /dev/null
@@ -1,23 +0,0 @@
----
-language: ruby
-
-cache: bundler
-# This will enable the container-based infrastructure for
-# travis tests. It should result in faster test vm load times.
-# @see http://docs.travis-ci.com/user/workers/container-based-infrastructure/
-sudo: false
-
-addons:
-  apt:
-    sources:
-      - kalakris-cmake
-    packages:
-      - cmake
-
-before_install:
-  - gem install rubygems-update -v '<3' --no-document && update_rubygems
-  - gem update bundler
-
-rvm:
-  - 2.6
-  - 2.7
diff --git a/Gemfile b/Gemfile
index b9e7bf42..7fb1127a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 gemspec
@@ -6,6 +8,8 @@ gem 'rake', require: false
 
 group :test do
   gem 'codeclimate-test-reporter'
-  gem 'rubocop', '~> 0.38.0'
   gem 'pry'
+  gem 'rubocop'
 end
+
+gem 'webrick', '~> 1.8'
diff --git a/Rakefile b/Rakefile
index 79c9da1e..e5544560 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'bundler/setup'
 require 'rspec/core/rake_task'
 require 'rubocop/rake_task'
@@ -10,4 +12,4 @@ end
 
 RSpec::Core::RakeTask.new(:spec)
 
-task default: [:spec, :rubocop]
+task default: %i[spec rubocop]
diff --git a/bin/moonshot b/bin/moonshot
index eb69ea8a..2badc150 100755
--- a/bin/moonshot
+++ b/bin/moonshot
@@ -1,11 +1,14 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 require 'moonshot'
 
 # This is the main entry point for the `moonshot` command-line tool.
 begin
   Moonshot::CommandLine.new.run!
-rescue => e
+rescue StandardError => e
   warn "#{e} (at #{e.backtrace.first})"
   raise e if ENV['MOONSHOT_BACKTRACE']
+
   exit 1
 end
diff --git a/lib/moonshot.rb b/lib/moonshot.rb
index 5b43024d..78cbd9e8 100644
--- a/lib/moonshot.rb
+++ b/lib/moonshot.rb
@@ -1,5 +1,8 @@
+# frozen_string_literal: true
+
 require 'English'
 require 'aws-sdk'
+
 require 'logger'
 require 'thor'
 require 'interactive-logger'
@@ -16,10 +19,13 @@ def self.config
 
   module ArtifactRepository
   end
+
   module BuildMechanism
   end
+
   module DeploymentMechanism
   end
+
   module Plugins
   end
 end
diff --git a/lib/moonshot/account_context.rb b/lib/moonshot/account_context.rb
index fa3f5171..f22cc24f 100644
--- a/lib/moonshot/account_context.rb
+++ b/lib/moonshot/account_context.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Moonshot
   module AccountContext
     def self.get
-      @account ||= determine_account_name
+      @get ||= determine_account_name
     end
 
     def self.set(account_name)
diff --git a/lib/moonshot/always_use_default_source.rb b/lib/moonshot/always_use_default_source.rb
index de4bf16a..18b56b20 100644
--- a/lib/moonshot/always_use_default_source.rb
+++ b/lib/moonshot/always_use_default_source.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # The AlwaysUseDefaultSource will always use the previous value in
   # the stack, or use the default value during stack creation. This is
@@ -5,12 +7,12 @@ module Moonshot
   # want to prompt the user for an override. Of course, overrides from
   # answer files or command-line arguments will always apply.
   class AlwaysUseDefaultSource
-    def get(sp)
+    def get(param)
       # Don't do anything, the default will apply on create, and the
       # previous value will be used on update.
-      return if sp.default?
+      return if param.default?
 
-      raise "Parameter #{sp.name} does not have a default, cannot use AlwaysUseDefaultSource!"
+      raise "Parameter #{param.name} does not have a default, cannot use AlwaysUseDefaultSource!"
     end
   end
 end
diff --git a/lib/moonshot/artifact_repository/s3_bucket.rb b/lib/moonshot/artifact_repository/s3_bucket.rb
index 8a849fd2..e2837988 100644
--- a/lib/moonshot/artifact_repository/s3_bucket.rb
+++ b/lib/moonshot/artifact_repository/s3_bucket.rb
@@ -47,7 +47,7 @@ def filename_for_version(version_name)
   def upload_to_s3(file, key)
     s3_client.put_object(
       acl: 'bucket-owner-full-control',
-      key: key,
+      key:,
       body: File.open(file),
       bucket: @bucket_name,
       storage_class: 'STANDARD_IA'
diff --git a/lib/moonshot/artifact_repository/s3_bucket_via_github_releases.rb b/lib/moonshot/artifact_repository/s3_bucket_via_github_releases.rb
index d15984d5..caac00c8 100644
--- a/lib/moonshot/artifact_repository/s3_bucket_via_github_releases.rb
+++ b/lib/moonshot/artifact_repository/s3_bucket_via_github_releases.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'moonshot/artifact_repository/s3_bucket'
 require 'moonshot/shell'
 require 'digest'
@@ -9,7 +11,7 @@
 module Moonshot::ArtifactRepository
   # S3 Bucket repository backed by GitHub releases.
   # If a SemVer package isn't found in S3, it is copied from GitHub releases.
-  class S3BucketViaGithubReleases < S3Bucket # rubocop:disable ClassLength
+  class S3BucketViaGithubReleases < S3Bucket # rubocop:disable Metrics/ClassLength
     include Moonshot::BuildMechanism
     include Moonshot::Shell
 
@@ -36,9 +38,7 @@ def store_hook(build_mechanism, version)
     # artifact repositories a hook before deploy.
     def filename_for_version(version)
       s3_name = super
-      if !@output_file && release?(version) && !in_s3?(s3_name)
-        github_to_s3(version, s3_name)
-      end
+      github_to_s3(version, s3_name) if !@output_file && release?(version) && !in_s3?(s3_name)
       s3_name
     end
 
@@ -51,7 +51,7 @@ def release?(version)
     end
 
     def in_s3?(key)
-      s3_client.head_object(key: key, bucket: bucket_name)
+      s3_client.head_object(key:, bucket: bucket_name)
     rescue ::Aws::S3::Errors::NotFound
       false
     end
@@ -62,7 +62,7 @@ def attach_release_asset(version, file)
 
       # If there is a checksum file, attach it as well. We only support MD5
       # since that's what S3 uses.
-      checksum_file = File.basename(file, '.tar.gz') + '.md5'
+      checksum_file = "#{File.basename(file, '.tar.gz')}.md5"
       cmd += " --attach=#{checksum_file}" if File.exist?(checksum_file)
 
       sh_step(cmd)
@@ -218,7 +218,7 @@ def backup_failed_s3_file(s3_name, attempt)
 
     def doctor_check_hub_release_download
       sh_out('hub release download --help')
-    rescue
+    rescue StandardError
       critical '`hub release download` command missing, upgrade hub.' \
                ' See https://github.com/github/hub/pull/1103'
     else
diff --git a/lib/moonshot/ask_user_source.rb b/lib/moonshot/ask_user_source.rb
index e01d90ba..c12c0381 100644
--- a/lib/moonshot/ask_user_source.rb
+++ b/lib/moonshot/ask_user_source.rb
@@ -1,24 +1,26 @@
+# frozen_string_literal: true
+
 require 'colorize'
 
 module Moonshot
   class AskUserSource
-    def get(sp)
+    def get(param)
       return unless Moonshot.config.interactive
 
-      @sp = sp
+      @param = param
 
       prompt
       loop do
         input = gets.chomp
 
-        if String(input).empty? && @sp.default?
+        if String(input).empty? && @param.default?
           # We will use the default value, print it here so the output is clear.
           puts 'Using default value.'
           return
         elsif String(input).empty?
-          puts "Cannot proceed without value for #{@sp.name}!"
+          puts "Cannot proceed without value for #{@param.name}!"
         else
-          @sp.set(String(input))
+          @param.set(String(input))
           return
         end
 
@@ -29,9 +31,9 @@ def get(sp)
     private
 
     def prompt
-      print "(#{@sp.name})".light_black
-      print " #{@sp.description}" unless @sp.description.empty?
-      print " [#{@sp.default}]".light_black if @sp.default?
+      print "(#{@param.name})".light_black
+      print " #{@param.description}" unless @param.description.empty?
+      print " [#{@param.default}]".light_black if @param.default?
       print ': '
     end
   end
diff --git a/lib/moonshot/build_mechanism/github_release.rb b/lib/moonshot/build_mechanism/github_release.rb
index 5fe56d9d..3bb27aac 100644
--- a/lib/moonshot/build_mechanism/github_release.rb
+++ b/lib/moonshot/build_mechanism/github_release.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'forwardable'
 require 'moonshot/shell'
 require 'open3'
@@ -40,9 +42,9 @@ def doctor_hook
       @build_mechanism.doctor_hook
     end
 
-    def resources=(r)
+    def resources=(res)
       super
-      @build_mechanism.resources = r
+      @build_mechanism.resources = res
     end
 
     def pre_build_hook(version)
@@ -135,6 +137,7 @@ def git_push_tag(remote, tag)
 
     def hub_create_release(semver, commitish, changelog_entry)
       return if hub_release_exists(semver)
+
       message = "#{semver}\n\n#{changelog_entry}"
       cmd = "hub release create #{semver} --commitish=#{commitish}"
       cmd << ' --prerelease' if semver.pre || semver.build
@@ -220,7 +223,7 @@ def releases_url
 
     def doctor_check_upstream
       sh_out('git remote | grep ^upstream$')
-    rescue => e
+    rescue StandardError => e
       critical "git remote `upstream` not found.\n#{e.message}"
     else
       success 'git remote `upstream` exists.'
@@ -228,7 +231,7 @@ def doctor_check_upstream
 
     def doctor_check_hub_auth
       sh_out('hub ci-status master')
-    rescue => e
+    rescue StandardError => e
       critical "`hub` failed, install hub and authorize it.\n#{e.message}"
     else
       success '`hub` installed and authorized.'
diff --git a/lib/moonshot/build_mechanism/script.rb b/lib/moonshot/build_mechanism/script.rb
index 75eef3a0..d51b9fd2 100644
--- a/lib/moonshot/build_mechanism/script.rb
+++ b/lib/moonshot/build_mechanism/script.rb
@@ -1,5 +1,6 @@
+# frozen_string_literal: true
+
 require 'open3'
-include Open3
 
 # Compile a release artifact using a shell script.
 #
@@ -18,6 +19,8 @@ class Moonshot::BuildMechanism::Script
   include Moonshot::ResourcesHelper
   include Moonshot::DoctorHelper
 
+  include Open3
+
   attr_reader :output_file
 
   def initialize(script, output_file: 'output.tar.gz')
@@ -35,12 +38,12 @@ def build_hook(version)
       'OUTPUT_FILE' => @output_file
     }
     ilog.start_threaded "Running Script: #{@script}" do |s|
-      run_script(s, env: env)
+      run_script(s, env:)
     end
   end
 
   def post_build_hook(_version)
-    unless File.exist?(@output_file) # rubocop:disable GuardClause
+    unless File.exist?(@output_file) # rubocop:disable Style/GuardClause
       raise 'Build command did not produce output file!'
     end
   end
@@ -61,10 +64,8 @@ def run_script(step, env: {})
       end
 
       result = wait.value
-      if result.exitstatus == 0
-        step.success "Build script #{@script} exited successfully!"
-      end
-      unless result.exitstatus == 0
+      step.success "Build script #{@script} exited successfully!" if result.exitstatus.zero?
+      unless result.exitstatus.zero?
         ilog.error "Build script failed with exit status #{result.exitstatus}!"
         ilog.error output.join("\n")
         step.failure "Build script #{@script} failed with exit status #{result.exitstatus}!"
diff --git a/lib/moonshot/build_mechanism/travis_deploy.rb b/lib/moonshot/build_mechanism/travis_deploy.rb
index d88ac9d7..abd69384 100644
--- a/lib/moonshot/build_mechanism/travis_deploy.rb
+++ b/lib/moonshot/build_mechanism/travis_deploy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'moonshot/shell'
 require 'travis'
 require 'travis/pro'
@@ -25,8 +27,7 @@ def initialize(slug, pro: false, timeout: 900)
       @cli_args = "-r #{@slug} #{@endpoint}"
     end
 
-    def pre_build_hook(_)
-    end
+    def pre_build_hook(_); end
 
     def build_hook(version)
       job_number = find_build_and_job(version)
@@ -34,8 +35,7 @@ def build_hook(version)
       check_build(version)
     end
 
-    def post_build_hook(_)
-    end
+    def post_build_hook(_); end
 
     private
 
@@ -120,7 +120,7 @@ def check_build(version)
 
     def doctor_check_travis_auth
       sh_out("bundle exec travis raw #{@endpoint} repos/#{@slug}")
-    rescue => e
+    rescue StandardError => e
       critical "`travis` not available or not authorized.\n#{e.message}"
     else
       success '`travis` installed and authorized.'
diff --git a/lib/moonshot/build_mechanism/version_proxy.rb b/lib/moonshot/build_mechanism/version_proxy.rb
index 273ddd6e..d529c8c8 100644
--- a/lib/moonshot/build_mechanism/version_proxy.rb
+++ b/lib/moonshot/build_mechanism/version_proxy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'forwardable'
 require 'semantic'
 
@@ -19,10 +21,10 @@ def doctor_hook
     @dev.doctor_hook
   end
 
-  def resources=(r)
+  def resources=(res)
     super
-    @release.resources = r
-    @dev.resources = r
+    @release.resources = res
+    @dev.resources = res
   end
 
   def pre_build_hook(version)
diff --git a/lib/moonshot/change_set.rb b/lib/moonshot/change_set.rb
index f61797a2..41ef9589 100644
--- a/lib/moonshot/change_set.rb
+++ b/lib/moonshot/change_set.rb
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 module Moonshot
   class ChangeSet
-    attr_reader :name
-    attr_reader :stack_name
+    attr_reader :name, :stack_name
 
     def initialize(name, stack_name)
       @name = name
@@ -11,9 +12,7 @@ def initialize(name, stack_name)
     end
 
     def confirm?
-      unless Moonshot.config.interactive
-        raise 'Cannot confirm ChangeSet when interactive mode is disabled!'
-      end
+      raise 'Cannot confirm ChangeSet when interactive mode is disabled!' unless Moonshot.config.interactive
 
       loop do
         print 'Apply changes? '
@@ -21,6 +20,7 @@ def confirm?
 
         return true if resp == 'yes'
         return false if resp == 'no'
+
         puts "Please enter 'yes' or 'no'!"
       end
     end
@@ -33,15 +33,16 @@ def invalid_reason
       @change_set.status_reason
     end
 
-    def display_changes
+    def display_changes # rubocop:disable Metrics/CyclomaticComplexity
       wait_for_change_set unless @change_set
 
       @change_set.changes.map(&:resource_change).each do |c|
         puts "* #{c.action} #{c.logical_resource_id} (#{c.resource_type})"
 
-        if c.replacement == 'True'
+        case c.replacement
+        when 'True'
           puts ' - Will be replaced'
-        elsif c.replacement == 'Conditional'
+        when 'Conditional'
           puts ' - May be replaced (Conditional)'
         end
 
@@ -60,14 +61,16 @@ def execute
       wait_for_change_set unless @change_set
       @cf_client.execute_change_set(
         change_set_name: @name,
-        stack_name: @stack_name)
+        stack_name: @stack_name
+      )
     end
 
     def delete
       wait_for_change_set unless @change_set
       @cf_client.delete_change_set(
         change_set_name: @name,
-        stack_name: @stack_name)
+        stack_name: @stack_name
+      )
     rescue Aws::CloudFormation::Errors::InvalidChangeSetStatus
       sleep 1
       retry
@@ -85,9 +88,10 @@ def wait_for_change_set
       loop do
         resp = @cf_client.describe_change_set(
           change_set_name: @name,
-          stack_name: @stack_name)
+          stack_name: @stack_name
+        )
 
-        if %w(CREATE_COMPLETE FAILED).include?(resp.status)
+        if %w[CREATE_COMPLETE FAILED].include?(resp.status)
           @change_set = resp
           return
         end
diff --git a/lib/moonshot/command.rb b/lib/moonshot/command.rb
index fe2ec2fa..3f0ebe51 100644
--- a/lib/moonshot/command.rb
+++ b/lib/moonshot/command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'optparse'
 
 module Moonshot
@@ -8,7 +10,7 @@ module ClassMethods
       attr_accessor :usage, :description, :only_in_account
     end
 
-    def self.inherited(base)
+    def self.inherited(base) # rubocop:disable Lint/MissingSuper
       Moonshot::CommandLine.register(base)
       base.extend(ClassMethods)
     end
@@ -44,7 +46,7 @@ def controller
       # Degrade to a more compatible logger if the terminal seems outdated,
       # or at the users request.
       if !$stdout.isatty || !@use_interactive_logger
-        log = Logger.new(STDOUT)
+        log = Logger.new($stdout)
         controller.config.interactive_logger = InteractiveLoggerProxy.new(log)
       end
 
diff --git a/lib/moonshot/command_line.rb b/lib/moonshot/command_line.rb
index 384161c2..29fd1e2a 100644
--- a/lib/moonshot/command_line.rb
+++ b/lib/moonshot/command_line.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # This class implements the command-line `moonshot` tool.
   class CommandLine
@@ -10,7 +12,7 @@ def self.registered_commands
       @classes || []
     end
 
-    def run! # rubocop:disable CyclomaticComplexity, MethodLength, PerceivedComplexity
+    def run! # rubocop:disable Metrics/MethodLength, Metrics/CyclomaticComplexity
       # Commands defined as Moonshot::Commands require a properly
       # configured Moonshot.rb and supporting files. Without them, we only
       # support `--help` and `new`.
@@ -24,7 +26,7 @@ def run! # rubocop:disable CyclomaticComplexity, MethodLength, PerceivedComplexi
 
         if Dir.pwd == '/'
           warn 'No Moonfile.rb found, are you in a project? Maybe you need to '\
-	        			'create one with `moonshot new <app_name>`?'
+               'create one with `moonshot new <app_name>`?'
           raise 'No Moonfile found'
         end
 
@@ -51,7 +53,7 @@ def run! # rubocop:disable CyclomaticComplexity, MethodLength, PerceivedComplexi
 
       # Determine what command is being run, which should be the first argument.
       command = ARGV.shift
-      if %w(--help -h help).include?(command) || command.nil?
+      if %w[--help -h help].include?(command) || command.nil?
         usage
         return
       end
@@ -94,7 +96,7 @@ def usage
       max_len = fields.map(&:first).map(&:size).max
 
       fields.each do |f|
-        line = format("  %-#{max_len}s # %s", *f)
+        line = format("  %-#{max_len}s # %s", *f) # rubocop:disable Lint/FormatParameterMismatch
         warn line
       end
     end
@@ -117,9 +119,9 @@ def load_commands
 
     def commandify(klass)
       word = klass.to_s.split('::').last
-      word.gsub!(/([A-Z\d]+)([A-Z][a-z])/, '\1_\2'.freeze)
-      word.gsub!(/([a-z\d])([A-Z])/, '\1_\2'.freeze)
-      word.tr!('_'.freeze, '-'.freeze)
+      word.gsub!(/([A-Z\d]+)([A-Z][a-z])/, '\1_\2')
+      word.gsub!(/([a-z\d])([A-Z])/, '\1_\2')
+      word.tr!('_', '-')
       word.downcase!
       word
     end
@@ -127,10 +129,11 @@ def commandify(klass)
     def handle_early_commands
       # If this is a legacy (Thor) help command, re-write it as
       # OptionParser format.
-      if ARGV[0] == 'help'
+      case ARGV[0]
+      when 'help'
         ARGV.delete_at(0)
         ARGV.push('-h')
-      elsif ARGV[0] == 'new'
+      when 'new'
         app_name = ARGV[1]
         ::Moonshot::Commands::New.run!(app_name)
         return true
diff --git a/lib/moonshot/command_line_dispatcher.rb b/lib/moonshot/command_line_dispatcher.rb
index 5fdfa6bc..e80c638b 100644
--- a/lib/moonshot/command_line_dispatcher.rb
+++ b/lib/moonshot/command_line_dispatcher.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   class CommandLineDispatcher
     def initialize(command, klass, args)
@@ -46,18 +48,14 @@ def build_parser(handler)
 
       # Each mechanism / plugin may manipulate the OptionParser object
       # associated with this command.
-      [:build_mechanism, :deployment_mechanism, :artifact_repository].each do |prov|
+      %i[build_mechanism deployment_mechanism artifact_repository].each do |prov|
         provider = Moonshot.config.send(prov)
 
-        if provider.respond_to?(hook_func_name(@command))
-          parser = provider.send(hook_func_name(@command), parser)
-        end
+        parser = provider.send(hook_func_name(@command), parser) if provider.respond_to?(hook_func_name(@command))
       end
 
       Moonshot.config.plugins.each do |plugin|
-        if plugin.respond_to?(hook_func_name(@command))
-          parser = plugin.send(hook_func_name(@command), parser)
-        end
+        parser = plugin.send(hook_func_name(@command), parser) if plugin.respond_to?(hook_func_name(@command))
       end
 
       parser
diff --git a/lib/moonshot/commands/console.rb b/lib/moonshot/commands/console.rb
index 07456534..ec2167f8 100644
--- a/lib/moonshot/commands/console.rb
+++ b/lib/moonshot/commands/console.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'pry'
 
 module Moonshot
diff --git a/lib/moonshot/commands/delete.rb b/lib/moonshot/commands/delete.rb
index 1f86107e..5d594bd4 100644
--- a/lib/moonshot/commands/delete.rb
+++ b/lib/moonshot/commands/delete.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class Delete < Moonshot::Command
@@ -8,7 +10,7 @@ class Delete < Moonshot::Command
 
       def parser
         parser = super
-        parser.on('--template-file=FILE', 'Override the path to the CloudFormation template.') do |v| # rubocop:disable LineLength
+        parser.on('--template-file=FILE', 'Override the path to the CloudFormation template.') do |v|
           Moonshot.config.template_file = v
         end
       end
diff --git a/lib/moonshot/commands/deploy.rb b/lib/moonshot/commands/deploy.rb
index 2ac16e12..e7cc0e1c 100644
--- a/lib/moonshot/commands/deploy.rb
+++ b/lib/moonshot/commands/deploy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class Deploy < Moonshot::Command
diff --git a/lib/moonshot/commands/doctor.rb b/lib/moonshot/commands/doctor.rb
index 01925294..eb56c644 100644
--- a/lib/moonshot/commands/doctor.rb
+++ b/lib/moonshot/commands/doctor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class Doctor < Moonshot::Command
diff --git a/lib/moonshot/commands/generate_template.rb b/lib/moonshot/commands/generate_template.rb
index 2532394f..364e028f 100644
--- a/lib/moonshot/commands/generate_template.rb
+++ b/lib/moonshot/commands/generate_template.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class GenerateTemplate < Moonshot::Command
diff --git a/lib/moonshot/commands/interactive_command.rb b/lib/moonshot/commands/interactive_command.rb
index 7abb4ccb..2416405b 100644
--- a/lib/moonshot/commands/interactive_command.rb
+++ b/lib/moonshot/commands/interactive_command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     module InteractiveCommand
diff --git a/lib/moonshot/commands/list.rb b/lib/moonshot/commands/list.rb
index b28574a4..7d2bd464 100644
--- a/lib/moonshot/commands/list.rb
+++ b/lib/moonshot/commands/list.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class List < Moonshot::Command
diff --git a/lib/moonshot/commands/new.rb b/lib/moonshot/commands/new.rb
index cf9fbc4f..fee675ce 100644
--- a/lib/moonshot/commands/new.rb
+++ b/lib/moonshot/commands/new.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class New < Moonshot::Command
@@ -25,6 +27,7 @@ def run!(application_name)
         def create_project_dir
           raise "Directory '#{@application_name}' already exists!" \
             if Dir.exist?(project_path)
+
           Dir.mkdir(project_path)
         end
 
@@ -42,34 +45,34 @@ def fill_moonfile
         end
 
         def generate_moonfile
-          <<-EOF
-Moonshot.config do |m|
-  m.app_name             = '#{@application_name}'
-  m.artifact_repository  = S3Bucket.new('<your_bucket>')
-  m.build_mechanism      = Script.new('bin/build.sh')
-  m.deployment_mechanism = CodeDeploy.new(asg: 'AutoScalingGroup')
-end
-EOF
+          <<~EOF
+            Moonshot.config do |m|
+              m.app_name             = '#{@application_name}'
+              m.artifact_repository  = S3Bucket.new('<your_bucket>')
+              m.build_mechanism      = Script.new('bin/build.sh')
+              m.deployment_mechanism = CodeDeploy.new(asg: 'AutoScalingGroup')
+            end
+          EOF
         end
 
         def print_success_message
-          warn <<-EOF
-Your application is configured, the following changes have been made
-to your project directory:
-
-  * Created Moonfile.rb, where you can configure your project.
-  * Created moonshot/plugins, where you can place custom Ruby code
-    to add hooks to core Moonshot actions (create, update, delete, etc.)
-  * Created moonshot/cli_extensions, where you can place custom Ruby
-    code to add your own project-specific commands to Moonshot.
-  * Created moonshot/template.yml, where you can build your
-    CloudFormation template.
-
-You will also need to ensure your Amazon account is configured for
-CodeDeploy by creating a role that allows deployments.
-
-See: http://moonshot.readthedocs.io/en/latest/mechanisms/deployment/
-EOF
+          warn <<~EOF
+            Your application is configured, the following changes have been made
+            to your project directory:
+
+              * Created Moonfile.rb, where you can configure your project.
+              * Created moonshot/plugins, where you can place custom Ruby code
+                to add hooks to core Moonshot actions (create, update, delete, etc.)
+              * Created moonshot/cli_extensions, where you can place custom Ruby
+                code to add your own project-specific commands to Moonshot.
+              * Created moonshot/template.yml, where you can build your
+                CloudFormation template.
+
+            You will also need to ensure your Amazon account is configured for
+            CodeDeploy by creating a role that allows deployments.
+
+            See: http://moonshot.readthedocs.io/en/latest/mechanisms/deployment/
+          EOF
         end
       end
     end
diff --git a/lib/moonshot/commands/parameter_arguments.rb b/lib/moonshot/commands/parameter_arguments.rb
index 1dec6a96..c377fc6f 100644
--- a/lib/moonshot/commands/parameter_arguments.rb
+++ b/lib/moonshot/commands/parameter_arguments.rb
@@ -1,4 +1,6 @@
-# rubocop:disable LineLength
+# frozen_string_literal: true
+
+# rubocop:disable Layout/LineLength
 module Moonshot
   module Commands
     module ParameterArguments
@@ -15,9 +17,7 @@ def parser
 
         parser.on('--parameter KEY=VALUE', '-PKEY=VALUE', 'Specify Stack Parameter on the command line') do |v|
           data = v.split('=', 2)
-          unless data.size == 2
-            raise "Invalid parameter format '#{v}', expected KEY=VALUE (e.g. MyStackParameter=12)"
-          end
+          raise "Invalid parameter format '#{v}', expected KEY=VALUE (e.g. MyStackParameter=12)" unless data.size == 2
 
           Moonshot.config.parameter_overrides[data[0]] = data[1]
         end
@@ -25,3 +25,4 @@ def parser
     end
   end
 end
+# rubocop:enable Layout/LineLength
diff --git a/lib/moonshot/commands/parent_stack_option.rb b/lib/moonshot/commands/parent_stack_option.rb
index 3fd32daf..b1ef7163 100644
--- a/lib/moonshot/commands/parent_stack_option.rb
+++ b/lib/moonshot/commands/parent_stack_option.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     module ParentStackOption
diff --git a/lib/moonshot/commands/push.rb b/lib/moonshot/commands/push.rb
index 62ff5291..c6d009a6 100644
--- a/lib/moonshot/commands/push.rb
+++ b/lib/moonshot/commands/push.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class Push < Moonshot::Command
diff --git a/lib/moonshot/commands/show_all_events_option.rb b/lib/moonshot/commands/show_all_events_option.rb
index f8921526..fe879bbe 100644
--- a/lib/moonshot/commands/show_all_events_option.rb
+++ b/lib/moonshot/commands/show_all_events_option.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     module ShowAllEventsOption
diff --git a/lib/moonshot/commands/status.rb b/lib/moonshot/commands/status.rb
index b35d8246..68caef32 100644
--- a/lib/moonshot/commands/status.rb
+++ b/lib/moonshot/commands/status.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class Status < Moonshot::Command
diff --git a/lib/moonshot/commands/tag_arguments.rb b/lib/moonshot/commands/tag_arguments.rb
index a09abe1a..8e8aef1f 100644
--- a/lib/moonshot/commands/tag_arguments.rb
+++ b/lib/moonshot/commands/tag_arguments.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     module TagArguments
@@ -6,9 +8,7 @@ def parser
 
         parser.on('--tag KEY=VALUE', '-TKEY=VALUE', 'Specify Stack Tag on the command line') do |v|
           data = v.split('=', 2)
-          unless data.size == 2
-            raise "Invalid tag format '#{v}', expected KEY=VALUE (e.g. MyStackTag=12)"
-          end
+          raise "Invalid tag format '#{v}', expected KEY=VALUE (e.g. MyStackTag=12)" unless data.size == 2
 
           Moonshot.config.extra_tags << { key: data[0], value: data[1] }
         end
diff --git a/lib/moonshot/commands/update.rb b/lib/moonshot/commands/update.rb
index 9e7a99cb..5dba1639 100644
--- a/lib/moonshot/commands/update.rb
+++ b/lib/moonshot/commands/update.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class Update < Moonshot::Command
@@ -12,7 +14,7 @@ class Update < Moonshot::Command
       def parser
         parser = super
 
-        parser.on('--dry-run', TrueClass, 'Show the changes that would be applied, but do not execute them') do |v| # rubocop:disable LineLength
+        parser.on('--dry-run', TrueClass, 'Show the changes that would be applied, but do not execute them') do |v|
           @dry_run = v
         end
 
@@ -24,7 +26,7 @@ def parser
           @refresh_parameters = v
         end
 
-        parser.on('--template-file=FILE', 'Override the path to the CloudFormation template.') do |v| # rubocop:disable LineLength
+        parser.on('--template-file=FILE', 'Override the path to the CloudFormation template.') do |v|
           Moonshot.config.template_file = v
         end
       end
diff --git a/lib/moonshot/commands/version.rb b/lib/moonshot/commands/version.rb
index ed75b54a..2530a684 100644
--- a/lib/moonshot/commands/version.rb
+++ b/lib/moonshot/commands/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Commands
     class Version < Moonshot::Command
diff --git a/lib/moonshot/config.rb b/lib/moonshot/config.rb
index e69de29b..8e9b8f90 100644
--- a/lib/moonshot/config.rb
+++ b/lib/moonshot/config.rb
@@ -0,0 +1 @@
+# frozen_string_literal: true
diff --git a/lib/moonshot/controller.rb b/lib/moonshot/controller.rb
index c42b04ad..cc81250e 100644
--- a/lib/moonshot/controller.rb
+++ b/lib/moonshot/controller.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 module Moonshot
   # The Controller coordinates and performs all Moonshot actions.
-  class Controller # rubocop:disable ClassLength
+  class Controller # rubocop:disable Metrics/ClassLength
     attr_accessor :config
 
     def initialize(config)
@@ -11,7 +13,7 @@ def list
       Moonshot::StackLister.new(@config.app_name).list
     end
 
-    def create # rubocop:disable AbcSize
+    def create # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
       run_plugins(:setup_create)
       # Scan the template for all required parameters and configure
       # the ParameterCollection.
@@ -35,7 +37,7 @@ def create # rubocop:disable AbcSize
 
       # Interview the user for missing parameters, using the
       # appropriate prompts.
-      @config.parameters.values.each do |sp|
+      @config.parameters.hash.each_value do |sp|
         next if sp.set?
 
         parameter_source = @config.parameter_sources.fetch(sp.name,
@@ -51,12 +53,12 @@ def create # rubocop:disable AbcSize
       # Fail if any parameters are still missing without defaults.
       missing_parameters = @config.parameters.missing_for_create
       unless missing_parameters.empty?
-        raise "The following parameters were not provided: #{missing_parameters.map(&:name).join(', ')}" # rubocop:disable LineLength
+        raise "The following parameters were not provided: #{missing_parameters.map(&:name).join(', ')}"
       end
 
       run_hook(:deploy, :pre_create)
       stack_ok = stack.create
-      if stack_ok # rubocop:disable GuardClause
+      if stack_ok # rubocop:disable Style/GuardClause
         run_hook(:deploy, :post_create)
         run_plugins(:post_create)
       else
@@ -64,7 +66,7 @@ def create # rubocop:disable AbcSize
       end
     end
 
-    def update(dry_run:, force:, refresh_parameters:) # rubocop:disable AbcSize
+    def update(dry_run:, force:, refresh_parameters:) # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
       run_plugins(:setup_update)
       # Scan the template for all required parameters and configure
       # the ParameterCollection.
@@ -108,11 +110,11 @@ def update(dry_run:, force:, refresh_parameters:) # rubocop:disable AbcSize
       # Fail if any parameters are still missing without defaults.
       missing_parameters = @config.parameters.missing_for_update
       unless missing_parameters.empty?
-        raise "The following parameters were not provided: #{missing_parameters.map(&:name).join(', ')}" # rubocop:disable LineLength
+        raise "The following parameters were not provided: #{missing_parameters.map(&:name).join(', ')}"
       end
 
       run_hook(:deploy, :pre_update)
-      stack.update(dry_run: dry_run, force: force)
+      stack.update(dry_run:, force:)
       run_hook(:deploy, :post_update)
       run_plugins(:post_update)
     end
@@ -159,7 +161,7 @@ def delete
       run_plugins(:pre_delete)
       run_hook(:deploy, :pre_delete)
       stack_ok = stack.delete
-      if stack_ok # rubocop:disable GuardClause
+      if stack_ok # rubocop:disable Style/GuardClause
         run_hook(:deploy, :post_delete)
         run_plugins(:post_delete)
       else
@@ -182,7 +184,8 @@ def doctor
     def ssh
       run_plugins(:pre_ssh)
       @config.ssh_instance ||= SSHTargetSelector.new(
-        stack, asg_name: @config.ssh_auto_scaling_group_name).choose!
+        stack, asg_name: @config.ssh_auto_scaling_group_name
+      ).choose!
       cb = SSHCommandBuilder.new(@config.ssh_config, @config.ssh_instance)
       result = cb.build(@config.ssh_command)
 
@@ -198,14 +201,14 @@ def stack
 
     def resources
       @resources ||=
-        Resources.new(stack: stack, ilog: @config.interactive_logger, controller: self)
+        Resources.new(stack:, ilog: @config.interactive_logger, controller: self)
     end
 
     def run_hook(type, name, *args)
       mech = get_mechanism(type)
       name = name.to_s << '_hook'
 
-      return unless mech && mech.respond_to?(name)
+      return unless mech.respond_to?(name)
 
       mech.resources = resources
       mech.send(name, *args)
@@ -215,6 +218,7 @@ def run_plugins(type)
       results = {}
       @config.plugins.each do |plugin|
         next unless plugin.respond_to?(type)
+
         results[plugin] =
           if type =~ /^setup_/
             plugin.send(type)
diff --git a/lib/moonshot/controller_config.rb b/lib/moonshot/controller_config.rb
index 90077f2c..c6486dcc 100644
--- a/lib/moonshot/controller_config.rb
+++ b/lib/moonshot/controller_config.rb
@@ -1,34 +1,16 @@
+# frozen_string_literal: true
+
 module Moonshot
   # Holds configuration for Moonshot::Controller
   class ControllerConfig
     attr_reader :account_alias
 
-    attr_accessor :additional_tag
-    attr_accessor :answer_file
-    attr_accessor :app_name
-    attr_accessor :artifact_repository
-    attr_accessor :build_mechanism
-    attr_accessor :changeset_wait_time
-    attr_accessor :deployment_mechanism
-    attr_accessor :dev_build_name_proc
-    attr_accessor :environment_name
-    attr_accessor :extra_tags
-    attr_accessor :interactive
-    attr_accessor :interactive_logger
-    attr_accessor :parameter_overrides
-    attr_accessor :parameters
-    attr_accessor :parent_stacks
-    attr_accessor :default_parameter_source
-    attr_accessor :parameter_sources
-    attr_accessor :plugins
-    attr_accessor :project_root
-    attr_accessor :show_all_stack_events
-    attr_accessor :ssh_auto_scaling_group_name
-    attr_accessor :ssh_command
-    attr_accessor :ssh_config
-    attr_accessor :ssh_instance
-    attr_accessor :template_file
-    attr_accessor :template_s3_bucket
+    attr_accessor :additional_tag, :answer_file, :app_name, :artifact_repository, :build_mechanism,
+                  :changeset_wait_time, :deployment_mechanism, :dev_build_name_proc, :environment_name,
+                  :extra_tags, :interactive, :interactive_logger, :parameter_overrides, :parameters, :parent_stacks,
+                  :default_parameter_source, :parameter_sources, :plugins, :project_root,
+                  :show_all_stack_events, :ssh_auto_scaling_group_name, :ssh_command, :ssh_config,
+                  :ssh_instance, :template_file, :template_s3_bucket
 
     def initialize
       @default_parameter_source = AskUserSource.new
diff --git a/lib/moonshot/creds_helper.rb b/lib/moonshot/creds_helper.rb
index 9d892c94..3de5380a 100644
--- a/lib/moonshot/creds_helper.rb
+++ b/lib/moonshot/creds_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # Create convenience methods for various AWS client creation.
   module CredsHelper
diff --git a/lib/moonshot/deployment_mechanism/code_deploy.rb b/lib/moonshot/deployment_mechanism/code_deploy.rb
index 1af73e82..9b4ec888 100644
--- a/lib/moonshot/deployment_mechanism/code_deploy.rb
+++ b/lib/moonshot/deployment_mechanism/code_deploy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'colorize'
 
 # This mechanism is used to deploy software to an auto-scaling group within
@@ -8,12 +10,12 @@
 #   self.artifact_repository = S3Bucket.new('foobucket')
 #   self.deployment_mechanism = CodeDeploy.new(asg: 'AutoScalingGroup')
 # end
-class Moonshot::DeploymentMechanism::CodeDeploy # rubocop:disable ClassLength
+class Moonshot::DeploymentMechanism::CodeDeploy # rubocop:disable Metrics/ClassLength
   include Moonshot::ResourcesHelper
   include Moonshot::CredsHelper
   include Moonshot::DoctorHelper
 
-  DEFAULT_ROLE_NAME = 'CodeDeployRole'.freeze
+  DEFAULT_ROLE_NAME = 'CodeDeployRole'
 
   # @param asg [Array, String]
   #   The logical name of the AutoScalingGroup to create and manage a Deployment
@@ -37,12 +39,13 @@ class Moonshot::DeploymentMechanism::CodeDeploy # rubocop:disable ClassLength
   #   CodeDeployDefault.OneAtATime.
   # rubocop:disable Metrics/ParameterLists
   def initialize(
-      asg: [],
-      optional_asg: [],
-      role: DEFAULT_ROLE_NAME,
-      app_name: nil,
-      group_name: nil,
-      config_name: 'CodeDeployDefault.OneAtATime')
+    asg: [],
+    optional_asg: [],
+    role: DEFAULT_ROLE_NAME,
+    app_name: nil,
+    group_name: nil,
+    config_name: 'CodeDeployDefault.OneAtATime'
+  )
     @asg_logical_ids = Array(asg)
     @optional_asg_logical_ids = Array(optional_asg)
     @app_name = app_name
@@ -51,6 +54,7 @@ def initialize(
     @codedeploy_config = config_name
     @ignore_app_stop_failures = false
   end
+  # rubocop:enable Metrics/ParameterLists
 
   def post_create_hook
     create_application_if_needed
@@ -62,7 +66,7 @@ def post_create_hook
   def post_update_hook
     post_create_hook
 
-    unless deployment_group_ok? # rubocop:disable GuardClause
+    unless deployment_group_ok? # rubocop:disable Style/GuardClause
       delete_deployment_group
       create_deployment_group_if_needed
     end
@@ -101,7 +105,7 @@ def post_delete_hook
   end
 
   def deploy_cli_hook(parser)
-    parser.on('--ignore-app-stop-failures', TrueClass, 'Continue deployment on ApplicationStop failures') do |v| # rubocop:disable LineLength
+    parser.on('--ignore-app-stop-failures', TrueClass, 'Continue deployment on ApplicationStop failures') do |v|
       puts "ignore = #{v}"
       @ignore_app_stop_failures = v
     end
@@ -178,27 +182,23 @@ def load_auto_scaling_groups
     autoscaling_groups = []
     @asg_logical_ids.each do |asg_logical_id|
       asg_name = stack.physical_id_for(asg_logical_id)
-      unless asg_name
-        raise "Could not find #{asg_logical_id} resource in Stack."
-      end
+      raise "Could not find #{asg_logical_id} resource in Stack." unless asg_name
 
       groups = as_client.describe_auto_scaling_groups(
-        auto_scaling_group_names: [asg_name])
-      if groups.auto_scaling_groups.empty?
-        raise "Could not find ASG #{asg_name}."
-      end
+        auto_scaling_group_names: [asg_name]
+      )
+      raise "Could not find ASG #{asg_name}." if groups.auto_scaling_groups.empty?
 
       autoscaling_groups.push(groups.auto_scaling_groups.first)
     end
     @optional_asg_logical_ids.each do |asg_logical_id|
       asg_name = stack.physical_id_for(asg_logical_id)
       next unless asg_name
+
       groups = as_client.describe_auto_scaling_groups(
         auto_scaling_group_names: [asg_name]
       )
-      unless groups.auto_scaling_groups.empty?
-        autoscaling_groups.push(groups.auto_scaling_groups.first)
-      end
+      autoscaling_groups.push(groups.auto_scaling_groups.first) unless groups.auto_scaling_groups.empty?
     end
     autoscaling_groups
   end
@@ -220,13 +220,15 @@ def application_exists?
 
   def deployment_group
     cd_client.get_deployment_group(
-      application_name: app_name, deployment_group_name: group_name)
+      application_name: app_name, deployment_group_name: group_name
+    )
              .deployment_group_info
   end
 
   def deployment_group_exists?
     cd_client.get_deployment_group(
-      application_name: app_name, deployment_group_name: group_name)
+      application_name: app_name, deployment_group_name: group_name
+    )
     true
   rescue Aws::CodeDeploy::Errors::ApplicationDoesNotExistException,
          Aws::CodeDeploy::Errors::DeploymentGroupDoesNotExistException
@@ -235,13 +237,13 @@ def deployment_group_exists?
 
   def deployment_group_ok?
     return false unless deployment_group_exists?
+
     asgs = deployment_group.auto_scaling_groups
     return false unless asgs
     return false unless asgs.count == auto_scaling_groups.count
+
     asgs.each do |asg|
-      if (auto_scaling_groups.find_index { |a| a.auto_scaling_group_name == asg.name }).nil?
-        return false
-      end
+      return false if (auto_scaling_groups.find_index { |a| a.auto_scaling_group_name == asg.name }).nil?
     end
     true
   end
@@ -284,7 +286,8 @@ def delete_deployment_group
     ilog.start "Deleting #{pretty_deploy_group}." do |s|
       cd_client.delete_deployment_group(
         application_name: app_name,
-        deployment_group_name: group_name)
+        deployment_group_name: group_name
+      )
       s.success
     end
   end
@@ -294,7 +297,8 @@ def create_deployment_group
       application_name: app_name,
       deployment_group_name: group_name,
       service_role_arn: role.arn,
-      auto_scaling_groups: asg_names)
+      auto_scaling_groups: asg_names
+    )
   end
 
   def wait_for_asg_capacity
@@ -306,10 +310,11 @@ def wait_for_asg_capacity
           count = asg.instances.count { |i| i.lifecycle_state == 'InService' }
           if asg.desired_capacity == count
             asgs_at_capacity += 1
-            s.continue "#{asg.auto_scaling_group_name} DesiredCapacity is #{asg.desired_capacity}, currently #{count} instance(s) are InService." # rubocop:disable LineLength
+            s.continue "#{asg.auto_scaling_group_name} DesiredCapacity is #{asg.desired_capacity}, currently #{count} instance(s) are InService." # rubocop:disable Layout/LineLength
           end
         end
         break if asgs.count == asgs_at_capacity
+
         sleep 5
       end
 
@@ -327,7 +332,7 @@ def wait_for_deployment(id, step)
 
       case status
       when 'Created', 'Queued', 'InProgress'
-        step.continue "Waiting for Deployment #{id.blue} to complete, current status is '#{status}'." # rubocop:disable LineLength
+        step.continue "Waiting for Deployment #{id.blue} to complete, current status is '#{status}'."
       when 'Succeeded'
         step.success "Deployment #{id.blue} completed successfully!"
         break
@@ -341,11 +346,11 @@ def wait_for_deployment(id, step)
     success
   end
 
-  def handle_deployment_failure(deployment_id)
-    instances = cd_client.list_deployment_instances(deployment_id: deployment_id)
+  def handle_deployment_failure(deployment_id) # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
+    instances = cd_client.list_deployment_instances(deployment_id:)
                          .instances_list.map do |instance_id|
-      cd_client.get_deployment_instance(deployment_id: deployment_id,
-                                        instance_id: instance_id)
+      cd_client.get_deployment_instance(deployment_id:,
+                                        instance_id:)
     end
 
     instances.map(&:instance_summary).each do |inst_summary|
@@ -373,7 +378,7 @@ def revision_for_artifact_repo(artifact_repo, version_name)
     when Moonshot::ArtifactRepository::S3Bucket
       s3_revision_for(artifact_repo, version_name)
     when NilClass
-      raise 'Must specify an ArtifactRepository with CodeDeploy. Take a look at the S3Bucket example.' # rubocop:disable LineLength
+      raise 'Must specify an ArtifactRepository with CodeDeploy. Take a look at the S3Bucket example.'
     else
       raise "Cannot use #{artifact_repo.class} to deploy with CodeDeploy."
     end
@@ -404,12 +409,12 @@ def create_deployment(artifact_repo, version_name)
   def doctor_check_code_deploy_role
     role
     success("#{@codedeploy_role} exists.")
-  rescue => e
-    help = <<-EOF
-Error: #{e.message}
+  rescue StandardError => e
+    help = <<~EOF
+      Error: #{e.message}
 
-For information on provisioning an account for use with CodeDeploy, see:
-http://docs.aws.amazon.com/codedeploy/latest/userguide/how-to-create-service-role.html
+      For information on provisioning an account for use with CodeDeploy, see:
+      http://docs.aws.amazon.com/codedeploy/latest/userguide/how-to-create-service-role.html
     EOF
     critical("Could not find #{@codedeploy_role}, ", help)
   end
@@ -419,7 +424,7 @@ def doctor_check_auto_scaling_resource_defined
       if stack.template.resource_names.include?(asg_logical_id)
         success("Resource '#{asg_logical_id}' exists in the CloudFormation template.")
       else
-        critical("Resource '#{asg_logical_id}' does not exist in the CloudFormation template!") # rubocop:disable LineLength
+        critical("Resource '#{asg_logical_id}' does not exist in the CloudFormation template!")
       end
     end
   end
diff --git a/lib/moonshot/doctor_helper.rb b/lib/moonshot/doctor_helper.rb
index f185235f..c802efa9 100644
--- a/lib/moonshot/doctor_helper.rb
+++ b/lib/moonshot/doctor_helper.rb
@@ -1,4 +1,5 @@
-# -*- coding: utf-8 -*-
+# frozen_string_literal: true
+
 require 'colorize'
 
 module Moonshot
@@ -19,18 +20,16 @@ def run_all_checks
       puts
       puts self.class.name.split('::').last
       private_methods.each do |meth|
-        begin
-          send(meth) if meth =~ /^doctor_check_/
-        rescue DoctorCritical
-          # Stop running checks in this Mechanism.
-          success = false
-          break
-        rescue => e
-          success = false
-          print '  ✗ '.red
-          puts "Exception while running check: #{e.class}: #{e.message.lines.first}"
-          break
-        end
+        send(meth) if meth =~ /^doctor_check_/
+      rescue DoctorCritical
+        # Stop running checks in this Mechanism.
+        success = false
+        break
+      rescue StandardError => e
+        success = false
+        print '  ✗ '.red
+        puts "Exception while running check: #{e.class}: #{e.message.lines.first}"
+        break
       end
 
       success
@@ -44,13 +43,13 @@ def success(str)
     def warning(str, additional_info = nil)
       print '  ? '.yellow
       puts str
-      additional_info.lines.each { |l| puts "      #{l}" } if additional_info
+      additional_info&.lines&.each { |l| puts "      #{l}" }
     end
 
     def critical(str, additional_info = nil)
       print '  ✗ '.red
       puts str
-      additional_info.lines.each { |l| puts "      #{l}" } if additional_info
+      additional_info&.lines&.each { |l| puts "      #{l}" }
       raise DoctorCritical
     end
   end
diff --git a/lib/moonshot/dynamic_template.rb b/lib/moonshot/dynamic_template.rb
index 48e3d51e..7e2f3a42 100644
--- a/lib/moonshot/dynamic_template.rb
+++ b/lib/moonshot/dynamic_template.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'erb'
 
 module Moonshot
@@ -51,6 +53,7 @@ def process
 
     def validate_destination_exists
       return unless File.file?(@destination)
+
       raise TemplateExists, "Output file '#{@destination}' already exists."
     end
 
diff --git a/lib/moonshot/interactive_logger_proxy.rb b/lib/moonshot/interactive_logger_proxy.rb
index 4fb8b5b8..d0edaa03 100644
--- a/lib/moonshot/interactive_logger_proxy.rb
+++ b/lib/moonshot/interactive_logger_proxy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'forwardable'
 
 module Moonshot
@@ -10,8 +12,7 @@ def initialize(logger)
         @logger = logger
       end
 
-      def blank
-      end
+      def blank; end
 
       def continue(str = nil)
         @logger.info(str) if str
@@ -21,8 +22,7 @@ def failure(str = 'Failure')
         @logger.error(str)
       end
 
-      def repaint
-      end
+      def repaint; end
 
       def success(str = 'Success')
         @logger.info(str)
diff --git a/lib/moonshot/parameter_collection.rb b/lib/moonshot/parameter_collection.rb
index edc90a77..2fccf901 100644
--- a/lib/moonshot/parameter_collection.rb
+++ b/lib/moonshot/parameter_collection.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # A Rigid Hash-like structure that only accepts manipulation of
   # parameters defined in the Stack template. Anything else results in
@@ -6,6 +8,7 @@ class ParameterCollection
     extend Forwardable
 
     def_delegators :@hash, :key?, :fetch, :[], :keys, :values
+    attr_reader :hash
 
     def self.from_template(template)
       obj = new
diff --git a/lib/moonshot/parent_stack_parameter_loader.rb b/lib/moonshot/parent_stack_parameter_loader.rb
index 468d3f17..edf6572b 100644
--- a/lib/moonshot/parent_stack_parameter_loader.rb
+++ b/lib/moonshot/parent_stack_parameter_loader.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   class ParentStackParameterLoader
     def initialize(config)
@@ -8,30 +10,32 @@ def load!
       @config.parent_stacks.each do |stack_name|
         count = 0
 
-        resp = cf_client.describe_stacks(stack_name: stack_name)
+        resp = cf_client.describe_stacks(stack_name:)
         raise "Parent Stack #{stack_name} not found!" unless resp.stacks.size == 1
 
         # If there is an input parameters matching a stack output, pass it.
         resp.stacks[0].outputs.each do |output|
           next unless @config.parameters.key?(output.output_key)
+
           # Our Stack has a Parameter matching this output. Set it's
           # value to the Output's value.
           count += 1
           @config.parameters.fetch(output.output_key).set(output.output_value)
         end
 
-        puts "Imported #{count} parameters from parent stack #{stack_name.blue}!" if count > 0
+        puts "Imported #{count} parameters from parent stack #{stack_name.blue}!" if count.positive?
       end
     end
 
     def load_missing_only!
       @config.parent_stacks.each do |stack_name|
-        resp = cf_client.describe_stacks(stack_name: stack_name)
+        resp = cf_client.describe_stacks(stack_name:)
         raise "Parent Stack #{stack_name} not found!" unless resp.stacks.size == 1
 
         # If there is an input parameters matching a stack output, pass it.
         resp.stacks[0].outputs.each do |output|
           next unless @config.parameters.key?(output.output_key)
+
           # Our Stack has a Parameter matching this output. Set it's
           # value to the Output's value, but only if we don't already
           # have a previous value we're using.
diff --git a/lib/moonshot/resources.rb b/lib/moonshot/resources.rb
index 7a954c36..addbe62b 100644
--- a/lib/moonshot/resources.rb
+++ b/lib/moonshot/resources.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # Resources is a dependency container that holds references to instances
   # provided to a Mechanism (build, deploy, etc.).
diff --git a/lib/moonshot/resources_helper.rb b/lib/moonshot/resources_helper.rb
index f6d48409..37457abb 100644
--- a/lib/moonshot/resources_helper.rb
+++ b/lib/moonshot/resources_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # Provides shorthand methods for accessing resources provided by the Resources
   # container.
@@ -8,16 +10,18 @@ module ResourcesHelper
 
     # TODO: Deprecate this interface.
     def log
-      @log ||= Logger.new(STDOUT)
+      @log ||= Logger.new($stdout)
     end
 
     def stack
       raise 'Resources not provided to Mechanism!' unless @resources
+
       @resources.stack
     end
 
     def ilog
       raise 'Resources not provided to Mechanism!' unless @resources
+
       @resources.ilog
     end
   end
diff --git a/lib/moonshot/shell.rb b/lib/moonshot/shell.rb
index 364e548e..eb373eb1 100644
--- a/lib/moonshot/shell.rb
+++ b/lib/moonshot/shell.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'thor'
 require 'retriable'
 
@@ -17,7 +19,7 @@ module Moonshot::Shell
 
   # Run a command, returning stdout. Stderr is suppressed unless the command
   # returns non-zero.
-  def sh_out(cmd, fail: true, stdin: '')
+  def sh_out(cmd, fail = true, stdin = '') # rubocop:disable Style/OptionalBooleanParameter
     r_in, w_in = IO.pipe
     r_out, w_out = IO.pipe
     r_err, w_err = IO.pipe
@@ -46,20 +48,18 @@ def sh_out(cmd, fail: true, stdin: '')
   module_function :sh_out
 
   def shell
-    @thor_shell ||= Thor::Base.shell.new
+    @shell ||= Thor::Base.shell.new
   end
 
   Thor::Shell::Basic.public_instance_methods(false).each do |meth|
     define_method(meth) { |*args| shell.public_send(meth, *args) }
   end
 
-  def sh_step(cmd, args = {})
+  def sh_step(cmd, **args)
     msg = args.delete(:msg) || cmd
-    if msg.length > (terminal_width - 18)
-      msg = "#{msg[0..(terminal_width - 22)]}..."
-    end
+    msg = "#{msg[0..(terminal_width - 22)]}..." if msg.length > (terminal_width - 18)
     ilog.start_threaded(msg) do |step|
-      out = sh_out(cmd, args)
+      out = sh_out(cmd, **args)
       yield step, out if block_given?
       step.success
     end
@@ -73,9 +73,9 @@ def sh_step(cmd, args = {})
   # @param opts [Hash] Options for retriable.
   #
   # @return [String] Stdout form the command.
-  def sh_retry(cmd, fail: true, stdin: '', opts: {})
+  def sh_retry(cmd, fail = true, stdin = '', opts: {}) # rubocop:disable Style/OptionalBooleanParameter
     Retriable.retriable(DEFAULT_RETRY_OPTIONS.merge(opts)) do
-      out = sh_out(cmd, stdin: stdin)
+      out = sh_out(cmd, stdin:)
       yield out if block_given?
       out
     end
diff --git a/lib/moonshot/ssh_command.rb b/lib/moonshot/ssh_command.rb
index ad24ac5d..13efb0ec 100644
--- a/lib/moonshot/ssh_command.rb
+++ b/lib/moonshot/ssh_command.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'thor'
 
 module Moonshot
diff --git a/lib/moonshot/ssh_command_builder.rb b/lib/moonshot/ssh_command_builder.rb
index dccca04e..40829e6f 100644
--- a/lib/moonshot/ssh_command_builder.rb
+++ b/lib/moonshot/ssh_command_builder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'shellwords'
 
 module Moonshot
@@ -26,7 +28,7 @@ def instance_ip
       @instance_ip ||= Aws::EC2::Client.new
                                        .describe_instances(instance_ids: [@instance_id])
                                        .reservations.first.instances.first.public_ip_address
-    rescue
+    rescue StandardError
       raise "Failed to determine public IP address for instance #{@instance_id}!"
     end
   end
diff --git a/lib/moonshot/ssh_config.rb b/lib/moonshot/ssh_config.rb
index 8f590f45..ae4791cf 100644
--- a/lib/moonshot/ssh_config.rb
+++ b/lib/moonshot/ssh_config.rb
@@ -1,8 +1,8 @@
+# frozen_string_literal: true
+
 module Moonshot
   class SSHConfig
-    attr_accessor :ssh_identity_file
-    attr_accessor :ssh_user
-    attr_accessor :ssh_options
+    attr_accessor :ssh_identity_file, :ssh_user, :ssh_options
 
     def initialize
       @ssh_identity_file = ENV['MOONSHOT_SSH_KEY_FILE']
diff --git a/lib/moonshot/ssh_fork_executor.rb b/lib/moonshot/ssh_fork_executor.rb
index 8fcf4796..348877a7 100644
--- a/lib/moonshot/ssh_fork_executor.rb
+++ b/lib/moonshot/ssh_fork_executor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'open3'
 
 module Moonshot
diff --git a/lib/moonshot/ssh_target_selector.rb b/lib/moonshot/ssh_target_selector.rb
index 2bb52f00..e1a8e5fc 100644
--- a/lib/moonshot/ssh_target_selector.rb
+++ b/lib/moonshot/ssh_target_selector.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # Choose a publically accessible instance to run commands on, given a Moonshot::Stack.
   class SSHTargetSelector
@@ -6,7 +8,7 @@ def initialize(stack, asg_name: nil)
       @stack = stack
     end
 
-    def choose!
+    def choose! # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
       groups = @stack.resources_of_type('AWS::AutoScaling::AutoScalingGroup')
 
       asg = if groups.count == 1
@@ -23,7 +25,7 @@ def choose!
       Aws::AutoScaling::Client.new.describe_auto_scaling_groups(
         auto_scaling_group_names: [asg.physical_resource_id]
       ).auto_scaling_groups.first.instances.map(&:instance_id).first
-    rescue => e
+    rescue StandardError => e
       raise "Failed to select an instance from the Auto Scaling Group: #{e.message}"
     end
   end
diff --git a/lib/moonshot/stack.rb b/lib/moonshot/stack.rb
index 2701534d..62a64bd9 100644
--- a/lib/moonshot/stack.rb
+++ b/lib/moonshot/stack.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'yaml'
 
 module Moonshot
@@ -5,12 +7,11 @@ module Moonshot
   # stores the state of the active stack running on AWS, but contains a
   # reference to the StackTemplate that would be applied with an update
   # action.
-  class Stack # rubocop:disable ClassLength
+  class Stack # rubocop:disable Metrics/ClassLength
     include CredsHelper
     include DoctorHelper
 
-    attr_reader :app_name
-    attr_reader :name
+    attr_reader :app_name, :name
 
     class << self
       def generate_name(config)
@@ -20,13 +21,11 @@ def generate_name(config)
       def make_tags(config)
         default_tags = [
           { key: 'moonshot_application', value: config.app_name },
-          { key: 'moonshot_environment', value: config.environment_name },
+          { key: 'moonshot_environment', value: config.environment_name }
         ]
         name = generate_name(config)
 
-        if config.additional_tag
-          default_tags << { key: config.additional_tag, value: name }
-        end
+        default_tags << { key: config.additional_tag, value: name } if config.additional_tag
 
         default_tags + config.extra_tags
       end
@@ -131,7 +130,7 @@ def physical_id_for(logical_id)
       resource_summary = resource_summaries.find do |r|
         r.logical_resource_id == logical_id
       end
-      resource_summary.physical_resource_id if resource_summary
+      resource_summary&.physical_resource_id
     end
 
     # @return [Array<Aws::CloudFormation::Types::StackResourceSummary>]
@@ -172,9 +171,11 @@ def load_template_file
 
         # Support the legacy file location from Moonshot 1.0.
         YamlStackTemplate.new(
-          File.join(@config.project_root, 'cloud_formation', "#{@config.app_name}.yml")),
+          File.join(@config.project_root, 'cloud_formation', "#{@config.app_name}.yml")
+        ),
         JsonStackTemplate.new(
-          File.join(@config.project_root, 'cloud_formation', "#{@config.app_name}.json"))
+          File.join(@config.project_root, 'cloud_formation', "#{@config.app_name}.json")
+        )
       ]
 
       # If a template file has been specified in the config, look there first.
@@ -186,6 +187,7 @@ def load_template_file
       template = templates.find(&:exist?)
 
       raise 'No template found in moonshot/template.{yml,json}!' unless template
+
       template
     end
 
@@ -204,9 +206,7 @@ def get_stack(name)
     end
 
     def upload_template_to_s3
-      unless @config.template_s3_bucket
-        raise 'The S3 bucket to store the template in is not configured.'
-      end
+      raise 'The S3 bucket to store the template in is not configured.' unless @config.template_s3_bucket
 
       s3_object_key = "#{@name}-#{Time.now.getutc.to_i}-#{File.basename(template.filename)}"
       template_url = "http://#{@config.template_s3_bucket}.s3.amazonaws.com/#{s3_object_key}"
@@ -226,7 +226,7 @@ def upload_template_to_s3
     def create_stack
       parameters = {
         stack_name: @name,
-        capabilities: %w(CAPABILITY_IAM CAPABILITY_NAMED_IAM),
+        capabilities: %w[CAPABILITY_IAM CAPABILITY_NAMED_IAM],
         parameters: @config.parameters.values.map(&:to_cf),
         tags: make_tags
       }
@@ -248,10 +248,10 @@ def new_change_set
       ].join('-')
 
       parameters = {
-        change_set_name: change_set_name,
+        change_set_name:,
         description: "Moonshot update command for application '#{Moonshot.config.app_name}'",
         stack_name: @name,
-        capabilities:  %w(CAPABILITY_IAM CAPABILITY_NAMED_IAM),
+        capabilities: %w[CAPABILITY_IAM CAPABILITY_NAMED_IAM],
         parameters: @config.parameters.values.map(&:to_cf),
         tags: make_tags
       }
@@ -276,36 +276,31 @@ def wait_for_stack_state(wait_target, past_tense_verb)
       events.show_only_errors unless @config.show_all_stack_events
 
       @ilog.start_threaded "Waiting for #{stack_name} to be successfully #{past_tense_verb}." do |s|
-        begin
-          cf_client.wait_until(wait_target, stack_name: stack_id) do |w|
-            w.delay = 10
-            w.max_attempts = 360 # 60 minutes.
-            w.before_wait do |attempt, resp|
-              begin
-                events.latest_events.each { |e| @ilog.error(format_event(e)) }
-                # rubocop:disable Lint/HandleExceptions
-              rescue Aws::CloudFormation::Errors::ValidationError
-                # Do nothing.  The above event logging block may result in
-                # a ValidationError while waiting for a stack to delete.
-              end
-              # rubocop:enable Lint/HandleExceptions
-
-              if attempt == w.max_attempts - 1
-                s.failure "#{stack_name} was not #{past_tense_verb} after 30 minutes."
-                result = false
-
-                # We don't want the interactive logger to catch an exception.
-                throw :success
-              end
-              s.continue "Waiting for CloudFormation Stack to be successfully #{past_tense_verb}, current status '#{resp.stacks.first.stack_status}'." # rubocop:disable LineLength
+        cf_client.wait_until(wait_target, stack_name: stack_id) do |w|
+          w.delay = 10
+          w.max_attempts = 360 # 60 minutes.
+          w.before_wait do |attempt, resp|
+            begin
+              events.latest_events.each { |e| @ilog.error(format_event(e)) }
+            rescue Aws::CloudFormation::Errors::ValidationError
+              # Do nothing.  The above event logging block may result in
+              # a ValidationError while waiting for a stack to delete.
             end
-          end
+            if attempt == w.max_attempts - 1
+              s.failure "#{stack_name} was not #{past_tense_verb} after 30 minutes."
+              result = false
 
-          s.success "#{stack_name} successfully #{past_tense_verb}." if result
-        rescue Aws::Waiters::Errors::FailureStateError
-          result = false
-          s.failure "#{stack_name} failed to update."
+              # We don't want the interactive logger to catch an exception.
+              throw :success
+            end
+            s.continue "Waiting for CloudFormation Stack to be successfully #{past_tense_verb}, current status '#{resp.stacks.first.stack_status}'." # rubocop:disable Layout/LineLength
+          end
         end
+
+        s.success "#{stack_name} successfully #{past_tense_verb}." if result
+      rescue Aws::Waiters::Errors::FailureStateError
+        result = false
+        s.failure "#{stack_name} failed to update."
       end
 
       result
@@ -347,7 +342,7 @@ def doctor_check_template_against_aws
       end
       cf_client.validate_template(validate_params)
       success('CloudFormation template is valid.')
-    rescue => e
+    rescue StandardError => e
       critical('Invalid CloudFormation template!', e.message)
     end
 
@@ -371,6 +366,7 @@ def execute_change_set(change_set)
 
       success = wait_for_stack_state(:stack_update_complete, 'updated')
       raise 'Failed to update the CloudFormation Stack.' unless success
+
       success
     end
   end
diff --git a/lib/moonshot/stack_asg_printer.rb b/lib/moonshot/stack_asg_printer.rb
index 79691182..e9b22f38 100644
--- a/lib/moonshot/stack_asg_printer.rb
+++ b/lib/moonshot/stack_asg_printer.rb
@@ -1,4 +1,5 @@
-# coding: utf-8
+# frozen_string_literal: true
+
 require 'colorize'
 require 'ruby-duration'
 
@@ -16,7 +17,8 @@ def initialize(stack, table)
     def print
       asgs.each do |asg|
         asg_info = as_client.describe_auto_scaling_groups(
-          auto_scaling_group_names: [asg.physical_resource_id])
+          auto_scaling_group_names: [asg.physical_resource_id]
+        )
                             .auto_scaling_groups.first
         t_asg_info = @table.add_leaf("ASG: #{asg.logical_resource_id}")
 
@@ -70,7 +72,7 @@ def health_color(health)
 
     # Get additional information about instances not returned by the ASG API.
     def get_addl_info(instance_ids)
-      resp = ec2_client.describe_instances(instance_ids: instance_ids)
+      resp = ec2_client.describe_instances(instance_ids:)
 
       data = {}
       resp.reservations.map(&:instances).flatten.each do |instance|
@@ -93,7 +95,7 @@ def add_asg_info(table, asg_info)
       table.add_line "Desired Capacity is #{dc} (Min: #{min}, Max: #{max})."
 
       lbs = asg_info.load_balancer_names
-      table.add_line "Has #{lbs.count.to_s.blue} Load Balancer(s): #{lbs.map(&:blue).join(', ')}" # rubocop:disable LineLength
+      table.add_line "Has #{lbs.count.to_s.blue} Load Balancer(s): #{lbs.map(&:blue).join(', ')}"
     end
 
     def create_instance_table(asg_info)
@@ -142,7 +144,8 @@ def uptime_format(launch_time)
     def add_recent_activity_leaf(table, asg_name)
       recent = table.add_leaf('Recent Activity')
       resp = as_client.describe_scaling_activities(
-        auto_scaling_group_name: asg_name).activities
+        auto_scaling_group_name: asg_name
+      ).activities
 
       rows = resp.sort_by(&:start_time).reverse.first(10).map do |activity|
         row_for_activity(activity)
diff --git a/lib/moonshot/stack_config.rb b/lib/moonshot/stack_config.rb
index 7093ce1a..86cf2018 100644
--- a/lib/moonshot/stack_config.rb
+++ b/lib/moonshot/stack_config.rb
@@ -1,8 +1,9 @@
+# frozen_string_literal: true
+
 module Moonshot
   # Configuration for the Moonshot::Stack class.
   class StackConfig
-    attr_accessor :parent_stacks
-    attr_accessor :show_all_events
+    attr_accessor :parent_stacks, :show_all_events
 
     def initialize
       @parent_stacks = []
diff --git a/lib/moonshot/stack_events_poller.rb b/lib/moonshot/stack_events_poller.rb
index 46a90092..e5c8080d 100644
--- a/lib/moonshot/stack_events_poller.rb
+++ b/lib/moonshot/stack_events_poller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # The StackEventsPoller queries DescribeStackEvents every time #latest_events
   # is invoked, filtering out events that have already been returned. It can
@@ -32,7 +34,7 @@ def latest_events
     def filter_events(events)
       if @errors_only
         events.select do |event|
-          %w(CREATE_FAILED UPDATE_FAILED DELETE_FAILED).include?(event.resource_status)
+          %w[CREATE_FAILED UPDATE_FAILED DELETE_FAILED].include?(event.resource_status)
         end
       else
         events
diff --git a/lib/moonshot/stack_list_printer.rb b/lib/moonshot/stack_list_printer.rb
index 30e5774c..4791e253 100644
--- a/lib/moonshot/stack_list_printer.rb
+++ b/lib/moonshot/stack_list_printer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   class StackListPrinter
     attr_accessor :stacks
diff --git a/lib/moonshot/stack_lister.rb b/lib/moonshot/stack_lister.rb
index 1203fd69..eacfefd5 100644
--- a/lib/moonshot/stack_lister.rb
+++ b/lib/moonshot/stack_lister.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # The StackLister is world renoun for it's ability to list stacks.
   class StackLister
@@ -9,11 +11,11 @@ def initialize(app_name)
     end
 
     # rubocop:disable Metrics/AbcSize
-    def list
+    def list # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
       result = []
       next_token = nil
       loop do
-        resp = cf_client.describe_stacks(next_token: next_token)
+        resp = cf_client.describe_stacks(next_token:)
         resp.stacks.each do |stack|
           app_tag = stack.tags.find { |t| t.key == 'moonshot_application' }
           env_tag = stack.tags.find { |t| t.key == 'moonshot_environment' }
@@ -22,15 +24,17 @@ def list
           if app_tag && app_tag.value == Moonshot.config.app_name
             result <<
               EnvironmentDescription.new(env_tag.value, stack.creation_time, stack.stack_status)
-          elsif legacy_tag && legacy_tag.value.start_with?(Moonshot.config.app_name)
+          elsif legacy_tag&.value&.start_with?(Moonshot.config.app_name)
             result <<
               EnvironmentDescription.new(legacy_tag.value, stack.creation_time, stack.stack_status)
           end
         end
         break unless resp.next_token
+
         next_token = resp.next_token
       end
       result.sort_by(&:name)
     end
+    # rubocop:enable Metrics/AbcSize
   end
 end
diff --git a/lib/moonshot/stack_output_printer.rb b/lib/moonshot/stack_output_printer.rb
index 59a67bf1..87e68f19 100644
--- a/lib/moonshot/stack_output_printer.rb
+++ b/lib/moonshot/stack_output_printer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # Display the stack outputs to the user.
   class StackOutputPrinter
diff --git a/lib/moonshot/stack_parameter.rb b/lib/moonshot/stack_parameter.rb
index d7c9df66..b4087113 100644
--- a/lib/moonshot/stack_parameter.rb
+++ b/lib/moonshot/stack_parameter.rb
@@ -1,8 +1,8 @@
+# frozen_string_literal: true
+
 module Moonshot
   class StackParameter
-    attr_reader :name
-    attr_reader :default
-    attr_reader :description
+    attr_reader :name, :default, :description
 
     def initialize(name, default: nil, use_previous: false, description: '')
       @default      = default
@@ -32,9 +32,7 @@ def set(value)
     end
 
     def use_previous!(value)
-      if @value
-        raise "Value already set for StackParameter #{@name}, cannot use previous value!"
-      end
+      raise "Value already set for StackParameter #{@name}, cannot use previous value!" if @value
 
       # Make the current value available to plugins.
       @value = value
@@ -42,9 +40,7 @@ def use_previous!(value)
     end
 
     def value
-      unless @value || default?
-        raise "No value set and no default for StackParameter #{@name}!"
-      end
+      raise "No value set and no default for StackParameter #{@name}!" unless @value || default?
 
       @value || default
     end
diff --git a/lib/moonshot/stack_parameter_printer.rb b/lib/moonshot/stack_parameter_printer.rb
index 7e7e0d2c..8fd31200 100644
--- a/lib/moonshot/stack_parameter_printer.rb
+++ b/lib/moonshot/stack_parameter_printer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # Displays information about existing stack parameters to the user, with
   # information on what a stack update would do.
@@ -18,7 +20,7 @@ def print
 
     def format_value(value)
       if value.size > 60
-        value[0..60] + '...'
+        "#{value[0..60]}..."
       else
         value
       end
diff --git a/lib/moonshot/stack_template.rb b/lib/moonshot/stack_template.rb
index 165878f2..e4a971ce 100644
--- a/lib/moonshot/stack_template.rb
+++ b/lib/moonshot/stack_template.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   # A StackTemplate loads the template from disk and stores information
   # about it.
diff --git a/lib/moonshot/task.rb b/lib/moonshot/task.rb
index 68ec97db..3393a47f 100644
--- a/lib/moonshot/task.rb
+++ b/lib/moonshot/task.rb
@@ -1,6 +1,9 @@
+# frozen_string_literal: true
+
 module Moonshot
   class Task
     attr_reader :name, :desc, :block
+
     def initialize(name, desc, &block)
       @name = name.to_sym
       @desc = desc
diff --git a/lib/moonshot/tools/asg_rollout.rb b/lib/moonshot/tools/asg_rollout.rb
index 0986ea90..aa40479d 100644
--- a/lib/moonshot/tools/asg_rollout.rb
+++ b/lib/moonshot/tools/asg_rollout.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Tools
-    class ASGRollout # rubocop:disable ClassLength
+    class ASGRollout # rubocop:disable  Metrics/ClassLength
       attr_accessor :config
 
       def initialize(controller:, logical_id:)
@@ -16,7 +18,7 @@ def run!
           new_instance = wait_for_new_instance
           begin
             wait_for_in_service(new_instance)
-          rescue
+          rescue StandardError
             next
           end
           break
@@ -74,6 +76,7 @@ def wait_for_in_service(new_instance)
               raise "Instance #{new_instance.blue} went OutOfService while waiting to join..."
             end
             break if instance_health.in_service?
+
             s.continue "Instance #{new_instance.blue} is #{instance_health}..."
             sleep @config.instance_health_delay
           end
@@ -83,22 +86,22 @@ def wait_for_in_service(new_instance)
       end
 
       def run_pre_detach(instance)
-        if @config.pre_detach
-          log.start_threaded "Running PreDetach hook on #{instance.blue}..." do |s|
-            he = HookExecEnvironment.new(@controller.config, instance)
-            if false == @config.pre_detach.call(he)
-              s.failure "PreDetach hook failed for #{instance.blue}!"
-              raise "PreDetach hook failed for #{instance.blue}!"
-            end
+        return unless @config.pre_detach
 
-            s.success "PreDetach hook complete for #{instance.blue}!"
+        log.start_threaded "Running PreDetach hook on #{instance.blue}..." do |s|
+          he = HookExecEnvironment.new(@controller.config, instance)
+          if @config.pre_detach.call(he) == false
+            s.failure "PreDetach hook failed for #{instance.blue}!"
+            raise "PreDetach hook failed for #{instance.blue}!"
           end
+
+          s.success "PreDetach hook complete for #{instance.blue}!"
         end
       end
 
       def detach(instance, decrement:)
         log.start_threaded "Detaching instance #{instance.blue}..." do |s|
-          asg.detach_instance(instance, decrement: decrement)
+          asg.detach_instance(instance, decrement:)
 
           if decrement
             s.success "Detached instance #{instance.blue}, and decremented DesiredCapacity."
@@ -115,6 +118,7 @@ def wait_for_out_of_service(instance)
           loop do
             instance_health = asg.instance_health(instance)
             break if instance_health.out_of_service?
+
             s.continue "Instance #{instance.blue} is #{instance_health}..."
             sleep @config.instance_health_delay
           end
@@ -155,9 +159,7 @@ def asg
         return @asg if @asg
 
         asg_name = @controller.stack.physical_id_for(@logical_id)
-        unless asg_name
-          raise "Could not find Auto Scaling Group #{@logical_id}!"
-        end
+        raise "Could not find Auto Scaling Group #{@logical_id}!" unless asg_name
 
         @asg ||= ASGRollout::ASG.new(asg_name)
       end
diff --git a/lib/moonshot/tools/asg_rollout/asg.rb b/lib/moonshot/tools/asg_rollout/asg.rb
index 44332572..9ecde519 100644
--- a/lib/moonshot/tools/asg_rollout/asg.rb
+++ b/lib/moonshot/tools/asg_rollout/asg.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Tools
     class ASGRollout
@@ -20,14 +22,15 @@ def set_max_and_desired(max, desired)
           autoscaling.update_auto_scaling_group(
             auto_scaling_group_name: @name,
             max_size: max,
-            desired_capacity: desired)
+            desired_capacity: desired
+          )
         end
 
         def non_conforming_instances
           asg = load_asg
 
           asg.instances
-             .select { |i| i.launch_configuration_name != asg.launch_configuration_name }
+             .reject { |i| i.launch_configuration_name == asg.launch_configuration_name }
              .map(&:instance_id)
         end
 
@@ -59,17 +62,17 @@ def detach_instance(id, decrement:)
           resp = autoscaling.detach_instances(
             auto_scaling_group_name: @name,
             instance_ids: [id],
-            should_decrement_desired_capacity: decrement)
+            should_decrement_desired_capacity: decrement
+          )
 
           activity = resp.activities.first
-          unless activity
-            raise 'Did not receive Activity from DetachInstances call!'
-          end
+          raise 'Did not receive Activity from DetachInstances call!' unless activity
 
           # Wait for the detach activity to complete:
           loop do
             resp = autoscaling.describe_scaling_activities(
-              auto_scaling_group_name: @name)
+              auto_scaling_group_name: @name
+            )
 
             current_status = resp.activities
                                  .find { |a| a.activity_id == activity.activity_id }
@@ -97,7 +100,8 @@ def instance_health(id)
 
         def asg_instance_state(id)
           resp = autoscaling.describe_auto_scaling_instances(
-            instance_ids: [id])
+            instance_ids: [id]
+          )
 
           instance_info = resp.auto_scaling_instances.first
           return 'Missing' unless instance_info
@@ -110,12 +114,11 @@ def elb_instance_state(id)
             load_balancer_name: elb_name,
             instances: [
               { instance_id: id }
-            ])
+            ]
+          )
 
           instance_info = resp.instance_states.first
-          unless instance_info
-            raise "Failed to call DescribeInstanceHealth for #{id}!"
-          end
+          raise "Failed to call DescribeInstanceHealth for #{id}!" unless instance_info
 
           instance_info.state
         rescue Aws::ElasticLoadBalancing::Errors::InvalidInstance
@@ -133,11 +136,10 @@ def loadbalancing
 
         def load_asg
           resp = autoscaling.describe_auto_scaling_groups(
-            auto_scaling_group_names: [@name])
+            auto_scaling_group_names: [@name]
+          )
 
-          if resp.auto_scaling_groups.empty?
-            raise "Failed to call DescribeAutoScalingGroups for #{@name}!"
-          end
+          raise "Failed to call DescribeAutoScalingGroups for #{@name}!" if resp.auto_scaling_groups.empty?
 
           asg = resp.auto_scaling_groups.first
           @last_seen_ids = asg.instances.map(&:instance_id)
@@ -149,9 +151,7 @@ def elb_name
           return @elb_name if @elb_name
 
           asg = load_asg
-          if asg.load_balancer_names.size > 1
-            raise 'ASGRollout does not support configurations with multiple ELBs!'
-          end
+          raise 'ASGRollout does not support configurations with multiple ELBs!' if asg.load_balancer_names.size > 1
 
           @elb_name ||= asg.load_balancer_names.first
         end
diff --git a/lib/moonshot/tools/asg_rollout/asg_instance.rb b/lib/moonshot/tools/asg_rollout/asg_instance.rb
index f4c3e32c..a86ff7d3 100644
--- a/lib/moonshot/tools/asg_rollout/asg_instance.rb
+++ b/lib/moonshot/tools/asg_rollout/asg_instance.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Tools
     class ASGRollout
diff --git a/lib/moonshot/tools/asg_rollout/hook_exec_environment.rb b/lib/moonshot/tools/asg_rollout/hook_exec_environment.rb
index 7ed13efc..761785de 100644
--- a/lib/moonshot/tools/asg_rollout/hook_exec_environment.rb
+++ b/lib/moonshot/tools/asg_rollout/hook_exec_environment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'moonshot/ssh_fork_executor'
 
 module Moonshot
diff --git a/lib/moonshot/tools/asg_rollout/instance_health.rb b/lib/moonshot/tools/asg_rollout/instance_health.rb
index 23cad106..09c67ace 100644
--- a/lib/moonshot/tools/asg_rollout/instance_health.rb
+++ b/lib/moonshot/tools/asg_rollout/instance_health.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Tools
     class ASGRollout
diff --git a/lib/moonshot/tools/asg_rollout_config.rb b/lib/moonshot/tools/asg_rollout_config.rb
index 84177034..0b12a5fd 100644
--- a/lib/moonshot/tools/asg_rollout_config.rb
+++ b/lib/moonshot/tools/asg_rollout_config.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Tools
     class ASGRolloutConfig
diff --git a/lib/moonshot/unicode_table.rb b/lib/moonshot/unicode_table.rb
index 917d2ac5..fb41e092 100644
--- a/lib/moonshot/unicode_table.rb
+++ b/lib/moonshot/unicode_table.rb
@@ -1,4 +1,4 @@
-# coding: utf-8
+# frozen_string_literal: true
 
 require 'colorize'
 
@@ -36,13 +36,13 @@ def add_table(table)
       table.each { |line| add_line(format(format, *line)) }
     end
 
-    def draw(depth = 1, first = true)
+    def draw(depth = 1, first = true) # rubocop:disable Style/OptionalBooleanParameter
       print first ? '┌' : '├'
       print '─' * depth
-      puts ' ' << @name.light_black
+      puts " #{@name.light_black}"
       @lines = [''] + @lines + ['']
       @lines.each do |line|
-        puts '│' << (' ' * depth) << line
+        puts "│#{' ' * depth}#{line}"
       end
       @children.each do |child|
         child.draw(depth + 1, false)
diff --git a/lib/moonshot/yaml_stack_template.rb b/lib/moonshot/yaml_stack_template.rb
index 72e57022..9ebb825b 100644
--- a/lib/moonshot/yaml_stack_template.rb
+++ b/lib/moonshot/yaml_stack_template.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'yaml'
 
 module Moonshot
diff --git a/lib/plugins/backup.rb b/lib/plugins/backup.rb
index 67e2b1b5..e5136cf4 100644
--- a/lib/plugins/backup.rb
+++ b/lib/plugins/backup.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rubygems/package'
 require 'zlib'
 require 'yaml'
@@ -20,7 +22,7 @@ class Backup # rubocop:disable Metrics/ClassLength
       def initialize
         yield self if block_given?
         validate_configuration
-        @target_name ||= '%{app_name}_%{timestamp}_%{user}.tar.gz'
+        @target_name ||= '%<app_name>s_%<timestamp>s_%<user>s.tar.gz'
       end
 
       # Factory method to create preconfigured Backup plugins. Uploads current
@@ -29,11 +31,12 @@ def initialize
       # @return [Backup] configured backup object
       def self.to_bucket(bucket)
         raise ArgumentError if bucket.nil? || bucket.empty?
+
         Moonshot::Plugins::Backup.new do |b|
           b.bucket = bucket
           b.backup_parameters = true
           b.backup_template = true
-          b.hooks = [:post_create, :post_update]
+          b.hooks = %i[post_create post_update]
         end
       end
 
@@ -53,27 +56,25 @@ def backup(resources)
         return if @target_bucket.nil?
 
         resources.ilog.start("#{log_message} in progress.") do |s|
-          begin
-            tar_out = tar(@files)
-            zip_out = zip(tar_out)
-            upload(zip_out)
-
-            s.success("#{log_message} succeeded.")
-          rescue => e
-            s.failure("#{log_message} failed: #{e}")
-          ensure
-            tar_out.close unless tar_out.nil?
-            zip_out.close unless zip_out.nil?
-          end
+          tar_out = tar(@files)
+          zip_out = zip(tar_out)
+          upload(zip_out)
+
+          s.success("#{log_message} succeeded.")
+        rescue StandardError => e
+          s.failure("#{log_message} failed: #{e}")
+        ensure
+          tar_out&.close
+          zip_out&.close
         end
       end
 
       # Dynamically responding to hooks supplied in the constructor
-      def method_missing(method_name, *args, &block)
+      def method_missing(method_name, *args, &block) # rubocop:disable Style/MissingRespondToMissing
         @hooks.include?(method_name) ? backup(*args) : super
       end
 
-      def respond_to?(method_name, include_private = false)
+      def respond_to?(method_name, include_private: false)
         @hooks.include?(method_name) || super
       end
 
@@ -110,7 +111,7 @@ def tar(target_files)
 
           # adding template file
           if @backup_template
-            template_file_path = render('cloud_formation/%{app_name}.json')
+            template_file_path = render('cloud_formation/%<app_name>s.json')
             add_file_to_tar(writer, template_file_path)
           end
         end
@@ -123,12 +124,10 @@ def tar(target_files)
       # @param writer [TarWriter]
       # @param file_name [String]
       def add_file_to_tar(writer, file_name)
-        writer.add_file(File.basename(file_name), 0644) do |io|
-          begin
-            File.open(file_name, 'r') { |f| io.write(f.read) }
-          rescue Errno::ENOENT
-            warn "'#{file_name}' was not found."
-          end
+        writer.add_file(File.basename(file_name), 0o644) do |io|
+          File.open(file_name, 'r') { |f| io.write(f.read) }
+        rescue Errno::ENOENT
+          warn "'#{file_name}' was not found."
         end
       end
 
@@ -139,7 +138,7 @@ def add_file_to_tar(writer, file_name)
       # @param target_filename [String]
       # @param content [String]
       def add_str_to_tar(writer, target_filename, content)
-        writer.add_file(File.basename(target_filename), 0644) do |io|
+        writer.add_file(File.basename(target_filename), 0o644) do |io|
           io.write(content.to_yaml)
         end
       end
@@ -165,11 +164,13 @@ def zip(io_tar)
       def upload(io_zip)
         opts = {}
         opts[:region] = @bucket_region if @bucket_region
-        s3_client(opts).put_object(
-          acl: 'private',
-          bucket: @target_bucket,
-          key: @target_name,
-          body: io_zip
+        s3_client(**opts).put_object(
+          {
+            acl: 'private',
+            bucket: @target_bucket,
+            key: @target_name,
+            body: io_zip
+          }
         )
       end
 
@@ -196,17 +197,13 @@ def iam_account
       end
 
       def define_bucket
-        case
         # returning already calculated bucket name
-        when @target_bucket
-          @target_bucket
+        return @target_bucket if @target_bucket
         # single bucket for all accounts
-        when @bucket
-          @bucket
+        return @bucket if @bucket
+
         # calculating bucket based on account name
-        when @buckets
-          bucket_by_account(iam_account)
-        end
+        bucket_by_account(iam_account) if @buckets
       end
 
       def bucket_by_account(account)
diff --git a/lib/plugins/code_deploy_setup.rb b/lib/plugins/code_deploy_setup.rb
index dd25fc6d..9959711c 100644
--- a/lib/plugins/code_deploy_setup.rb
+++ b/lib/plugins/code_deploy_setup.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Plugins
     # Plugin to ensure CodeDeploy has all necessary S3 buckets created.
@@ -33,11 +35,11 @@ def bucket_prefix
       # Create an S3 bucket in each supported region for CodeDeploy
       def setup_code_deploy_s3_buckets
         @regions.uniq.each do |region|
-          client = s3_client(region: region)
+          client = s3_client(region:)
           name = bucket_name(region)
           bucket = Aws::S3::Bucket.new(
             name,
-            client: client
+            client:
           )
           bucket.create unless bucket.exists?
         end
diff --git a/lib/plugins/dynamic_template.rb b/lib/plugins/dynamic_template.rb
index e15b8ffd..cc252029 100644
--- a/lib/plugins/dynamic_template.rb
+++ b/lib/plugins/dynamic_template.rb
@@ -1,11 +1,13 @@
+# frozen_string_literal: true
+
 module Moonshot
   module Plugins
     class DynamicTemplate
       def initialize(source:, parameters:, destination:)
         @dynamic_template = ::Moonshot::DynamicTemplate.new(
-          source: source,
-          parameters: parameters,
-          destination: destination
+          source:,
+          parameters:,
+          destination:
         )
       end
 
@@ -14,7 +16,7 @@ def run_hook
       end
 
       def cli_hook(parser)
-        parser.on('--template-file=FILE', 'Override the path to the CloudFormation template.') do |v| # rubocop:disable LineLength
+        parser.on('--template-file=FILE', 'Override the path to the CloudFormation template.') do |v|
           @dynamic_template.destination = v
           Moonshot.config.template_file = v
         end
diff --git a/lib/plugins/encrypted_parameters.rb b/lib/plugins/encrypted_parameters.rb
index e8ce381f..ac367815 100644
--- a/lib/plugins/encrypted_parameters.rb
+++ b/lib/plugins/encrypted_parameters.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This plugin encrypts parameters of the stack using a KMS Key,
 # storing and passing the key used to the stack as a parameter as
 # well. The resources in the stack can then use that KMS Key to
@@ -96,13 +98,13 @@ def find_or_create_kms_key
 
         @ilog.start_threaded "Checking for KMS Key #{@kms_key_parameter_name}" do |s|
           if Moonshot.config.parameters.key?(@kms_key_parameter_name)
-            if 'Auto' == Moonshot.config.parameters[@kms_key_parameter_name].value
+            if Moonshot.config.parameters[@kms_key_parameter_name].value == 'Auto'
               s.continue "Auto-generating KMS Key for #{@kms_key_parameter_name.blue}... "
               key_arn = KmsKey.create.arn
               Moonshot.config.parameters[@kms_key_parameter_name].set(key_arn)
               s.success "Created a new KMS Key for #{@kms_key_parameter_name.blue}!"
             else
-              kms=KmsKey.new(Moonshot.config.parameters[@kms_key_parameter_name].value)
+              kms = KmsKey.new(Moonshot.config.parameters[@kms_key_parameter_name].value)
               key_arn = kms.arn
               kms.update
               s.success "Using existing KMS Key for #{@kms_key_parameter_name.blue}!"
diff --git a/lib/plugins/encrypted_parameters/kms_key.rb b/lib/plugins/encrypted_parameters/kms_key.rb
index 62e8fa91..6dfcf4dd 100644
--- a/lib/plugins/encrypted_parameters/kms_key.rb
+++ b/lib/plugins/encrypted_parameters/kms_key.rb
@@ -1,4 +1,6 @@
-require_relative '../../moonshot/stack.rb'
+# frozen_string_literal: true
+
+require_relative '../../moonshot/stack'
 
 module Moonshot
   module Plugins
@@ -6,19 +8,20 @@ class EncryptedParameters
       # Class that manages KMS keys in AWS.
       class KmsKey
         attr_reader :arn
+
         class << self
           def create
             standard_tags = stack_tags
             resp = Aws::KMS::Client.new.create_key({
-               tags:  standard_tags, # An array of tags.
-              })
+                                                     tags: standard_tags # An array of tags.
+                                                   })
             arn = resp.key_metadata.arn
             new(arn)
           end
 
           def stack_tags
             tags = Moonshot::Stack.make_tags(Moonshot.config)
-            tags.map { |tag| { tag_key:  tag[:key], tag_value:  tag[:value] } }
+            tags.map { |tag| { tag_key: tag[:key], tag_value: tag[:value] } }
           end
         end
 
@@ -30,9 +33,9 @@ def initialize(arn)
         def update
           standard_tags = self.class.stack_tags
           @kms_client.tag_resource({
-            key_id: @arn, # arn of the CMK being tagged
-            tags: standard_tags, # An array of tags.
-          })
+                                     key_id: @arn, # arn of the CMK being tagged
+                                     tags: standard_tags # An array of tags.
+                                   })
         end
 
         def delete
diff --git a/lib/plugins/encrypted_parameters/parameter_encrypter.rb b/lib/plugins/encrypted_parameters/parameter_encrypter.rb
index b5c1d0fb..344be8ae 100644
--- a/lib/plugins/encrypted_parameters/parameter_encrypter.rb
+++ b/lib/plugins/encrypted_parameters/parameter_encrypter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'base64'
 module Moonshot
   module Plugins
diff --git a/lib/plugins/rotate_asg_instances/asg.rb b/lib/plugins/rotate_asg_instances/asg.rb
index e50568f7..4031c9e2 100644
--- a/lib/plugins/rotate_asg_instances/asg.rb
+++ b/lib/plugins/rotate_asg_instances/asg.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module RotateAsgInstances
     class ASG # rubocop:disable Metrics/ClassLength
@@ -67,7 +69,6 @@ def identify_outdated_instances
       def with_scale_up
         scaled_up = scale_up_if_possible
         yield
-
       rescue StandardError => e
         @ilog.error("Failure encountered during scale up to the desired capacity: #{e.message}")
       ensure
@@ -110,7 +111,7 @@ def outdated_volumes(outdated_instances)
           begin
             inst = Aws::EC2::Instance.new(id: i.id)
             first_block_device = inst.block_device_mappings.first
-            volumes << first_block_device.ebs.volume_id if first_block_device
+            volumes << first_block_device[:ebs][:volume_id] if first_block_device
           rescue StandardError => e
             # We're catching all errors here, because failing to reap a volume
             # is not a critical error, will not cause issues with the update.
@@ -187,6 +188,7 @@ def detach_instance(instance)
           true
         rescue Aws::AutoScaling::Errors::ValidationError => e
           raise e unless e.message.include?('is not part of Auto Scaling group')
+
           wait_for_capacity
           false
         rescue StandardError => e
@@ -203,7 +205,7 @@ def detach_instance(instance)
       def reattach_instance(instance)
         instance.load
         return unless instance.data.nil? \
-          || %w(Detached Detaching).include?(instance.lifecycle_state)
+          || %w[Detached Detaching].include?(instance.lifecycle_state)
 
         until instance.data.nil? || instance.lifecycle_state == 'Detached'
           sleep 10
@@ -218,6 +220,7 @@ def reattach_instance(instance)
       #   List of instances to terminate. Defaults to all instances with outdated
       #   launch configurations.
       def terminate_instances(shutdown_instances)
+        @ilog.info("Terminate instances: #{shutdown_instances}")
         if shutdown_instances.any?
           @step.continue(
             "Terminating #{shutdown_instances.size} outdated instances..."
@@ -231,7 +234,7 @@ def terminate_instances(shutdown_instances)
             next
           end
 
-          next unless %w(stopping stopped).include?(instance.state.name)
+          next unless %w[stopping stopped].include?(instance.state[:name])
 
           instance.wait_until_stopped
 
@@ -249,15 +252,13 @@ def scale_asg(new_desired_capacity)
 
       def reap_volumes(volumes)
         volumes.each do |volume_id|
-          begin
-            @step.continue("Deleting volume: #{volume_id}")
-            ec2_client(region: ENV['AWS_REGION'])
-              .delete_volume(volume_id: volume_id)
-          rescue StandardError => e
-            # We're catching all errors here, because failing to reap a volume
-            # is not a critical error, will not cause issues with the release.
-            @step.failure("Failed to delete volume #{volume_id}: #{e.message}")
-          end
+          @step.continue("Deleting volume: #{volume_id}")
+          ec2_client(region: ENV['AWS_REGION'])
+            .delete_volume(volume_id:)
+        rescue StandardError => e
+          # We're catching all errors here, because failing to reap a volume
+          # is not a critical error, will not cause issues with the release.
+          @step.failure("Failed to delete volume #{volume_id}: #{e.message}")
         end
       end
 
@@ -277,7 +278,7 @@ def wait_for_capacity
           @step.continue("Instances: #{instances.join(', ')}")
         end
 
-        asg.reload.wait_until(before_wait: before_wait, max_attempts: 60,
+        asg.reload.wait_until(before_wait:, max_attempts: 60,
                               delay: 30) do |a|
           instances_up = a.instances.select do |i|
             i.lifecycle_state == 'InService'
@@ -292,8 +293,9 @@ def wait_for_capacity
       #
       # @param id [String] ID of the instance to terminate.
       def shutdown_instance(id)
-        instance = Aws::EC2::Instance.new(id: id)
+        instance = Aws::EC2::Instance.new(id:)
         return if instance_in_terminal_state?(instance)
+
         @ssh.exec('sudo shutdown -h now', id)
         instance.wait_until_stopped
       end
@@ -304,12 +306,13 @@ def instance_in_terminal_state?(instance)
                 elsif instance.is_a?(Aws::AutoScaling::Instance)
                   check_asg_instance(instance)
                 end
-        %w(Terminating Terminated).include?(state)
+        %w[Terminating Terminated].include?(state)
       end
 
       def check_ec2_instance(instance)
+        @ilog.info("Check ec2 instance: #{instance}")
         if instance.exists?
-          instance.state.name
+          instance.state[:name]
         else
           'Terminated'
         end
diff --git a/lib/plugins/rotate_asg_instances/ssh.rb b/lib/plugins/rotate_asg_instances/ssh.rb
index e23d079c..ae29067a 100644
--- a/lib/plugins/rotate_asg_instances/ssh.rb
+++ b/lib/plugins/rotate_asg_instances/ssh.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Moonshot
   module RotateAsgInstances
     class SSHValidationError < StandardError
@@ -15,6 +17,7 @@ def test_ssh_connection(instance_id)
           # rubocop:disable Style/RaiseArgs
           raise SSHValidationError.new(response) unless
             response.exitstatus.zero?
+          # rubocop:enable Style/RaiseArgs
         end
       end
 
diff --git a/moonshot.gemspec b/moonshot.gemspec
index a177dd49..0a4daff6 100644
--- a/moonshot.gemspec
+++ b/moonshot.gemspec
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 Gem::Specification.new do |s|
   s.name        = 'moonshot'
-  s.version     = '2.0.0.beta6'
+  s.version     = '3.0.0'
   s.licenses    = ['Apache-2.0']
   s.summary     = 'A library and CLI tool for launching services into AWS'
   s.description = 'A library and CLI tool for launching services into AWS.'
@@ -14,6 +16,8 @@ Gem::Specification.new do |s|
   s.homepage    = 'https://github.com/acquia/moonshot'
 
   s.add_dependency('aws-sdk', '~> 2.0', '>= 2.2.0')
+  s.required_ruby_version = '>= 3.1.2'
+
   s.add_dependency('activesupport')
   s.add_dependency('colorize')
   s.add_dependency('highline')
diff --git a/sample/Gemfile b/sample/Gemfile
index 06e72e9a..c8e8217f 100644
--- a/sample/Gemfile
+++ b/sample/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 gem 'moonshot', '~> 0.7.0'
diff --git a/spec/moonshot/commands/build_spec.rb b/spec/moonshot/commands/build_spec.rb
index bf7424e7..addcf919 100644
--- a/spec/moonshot/commands/build_spec.rb
+++ b/spec/moonshot/commands/build_spec.rb
@@ -5,7 +5,7 @@
     parser = cli_dispatcher.send(:build_parser, subject)
     expect { parser.parse(%w(--skip-ci-status)) }.to raise_error(RuntimeError)
   end
-  
+
   it 'should not raise RuntimeError when send --skip-ci-status param with GithubRelease plugin' do
     Moonshot.config = Moonshot::ControllerConfig.new
     Moonshot.config do |c|
@@ -14,6 +14,6 @@
     cli_dispatcher = Moonshot::CommandLineDispatcher.new('build', subject, {})
     parser = cli_dispatcher.send(:build_parser, subject)
     expect { parser.parse(%w(--skip-ci-status)) }.to_not raise_error
-  end 
-  
+  end
+
 end
diff --git a/spec/moonshot/shell_spec.rb b/spec/moonshot/shell_spec.rb
index 28de2346..c18ccbe3 100644
--- a/spec/moonshot/shell_spec.rb
+++ b/spec/moonshot/shell_spec.rb
@@ -27,7 +27,7 @@ module Moonshot
       end
 
       it 'should not raise if fail is disabled.' do
-        sh_out('false', fail: false)
+        sh_out('false', false)
       end
     end
 
diff --git a/spec/moonshot/stack_spec.rb b/spec/moonshot/stack_spec.rb
index 2a4068d2..4a243008 100644
--- a/spec/moonshot/stack_spec.rb
+++ b/spec/moonshot/stack_spec.rb
@@ -97,7 +97,7 @@
       end
 
       context 'when template_s3_bucket is set' do
-        let(:time_obj) { Time.new('2017-11-07 12:00:00 +0000') }
+        let(:time_obj) { Time.parse('2017-11-07 12:00:00 +0000') }
 
         before(:each) do
           config.template_s3_bucket = 'rspec-bucket'