Webhooks notifications based on ENV vars (brotandgames#25)

* Add basic structure for Webhooks notifications

* Webhooks final implementation

* Add tests for webhooks notifications

* Fix Rubocop

* Fix typo '#notify' instead of '#notiy'

Co-Authored-By: Brot & Games <[email protected]>

* Add example configuration for RocketChat.

* Create mail notification + introduce url and check_url

* Fix a typo at webhook_configuration.md

* Fix log entry when status changed.

.rubocop.yml

@@ -1,16 +1,19 @@
 inherit_from: .rubocop_todo.yml
 
 Metrics/AbcSize:
-  Max: 40
+  Enabled: false
 
 Metrics/BlockLength:
-  Max: 300
+  Enabled: false
 
 Metrics/CyclomaticComplexity:
-  Max: 10
+  Enabled: false
 
 Metrics/MethodLength:
-  Max: 35
+  Enabled: false
 
 Metrics/PerceivedComplexity:
-  Max: 10
+  Enabled: false
+
+Metrics/LineLength:
+  Enabled: false

Gemfile

@@ -18,7 +18,7 @@ gem 'webpacker', '~> 4.0'
 # Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
 gem 'turbolinks', '~> 5'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
-gem 'jbuilder', '~> 2.5'
+gem 'jbuilder', '~> 2.9'
 # Use Redis adapter to run Action Cable in production
 # gem 'redis', '~> 4.0'
 # Use Active Model has_secure_password
@@ -49,9 +49,11 @@ end
 group :test do
   # Adds support for Capybara system testing and selenium driver
   gem 'capybara', '>= 2.15'
+  gem 'mocha'
   gem 'selenium-webdriver'
   # Easy installation and use of web drivers to run system tests with browsers
   gem 'webdrivers'
+  gem 'webmock'
 end
 
 group :development, :test do

Gemfile.lock

@@ -81,6 +81,8 @@ GEM
     childprocess (1.0.1)
       rake (< 13.0)
     concurrent-ruby (1.1.5)
+    crack (0.4.3)
+      safe_yaml (~> 1.0.0)
     crass (1.0.4)
     erubi (1.8.0)
     et-orbi (1.2.1)
@@ -92,12 +94,12 @@ GEM
       raabro (~> 1.1)
     globalid (0.4.2)
       activesupport (>= 4.2.0)
+    hashdiff (1.0.0)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
     jaro_winkler (1.5.3)
-    jbuilder (2.8.0)
+    jbuilder (2.9.1)
       activesupport (>= 4.2.0)
-      multi_json (>= 1.2)
     launchy (2.4.3)
       addressable (~> 2.3)
     letter_opener (1.7.0)
@@ -113,13 +115,15 @@ GEM
       mini_mime (>= 0.1.1)
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
+    metaclass (0.0.4)
     method_source (0.9.2)
     mimemagic (0.3.3)
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
+    mocha (1.9.0)
+      metaclass (~> 0.0.1)
     msgpack (1.2.10)
-    multi_json (1.13.1)
     nio4r (2.3.1)
     nokogiri (1.10.3)
       mini_portile2 (~> 2.4.0)
@@ -179,6 +183,7 @@ GEM
     rubyzip (1.2.2)
     rufus-scheduler (3.6.0)
       fugit (~> 1.1, >= 1.1.6)
+    safe_yaml (1.0.5)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
@@ -238,6 +243,10 @@ GEM
       nokogiri (~> 1.6)
       rubyzip (~> 1.0)
       selenium-webdriver (~> 3.0)
+    webmock (3.6.0)
+      addressable (>= 2.3.6)
+      crack (>= 0.3.2)
+      hashdiff (>= 0.4.0, < 2.0.0)
     webpacker (4.0.2)
       activesupport (>= 4.2)
       rack-proxy (>= 0.6.1)
@@ -248,7 +257,7 @@ GEM
     xpath (3.2.0)
       nokogiri (~> 1.8)
     yard (0.9.20)
-    zeitwerk (2.1.6)
+    zeitwerk (2.1.9)
 
 PLATFORMS
   ruby
@@ -258,9 +267,10 @@ DEPENDENCIES
   bootstrap (~> 4.3.1)
   byebug
   capybara (>= 2.15)
-  jbuilder (~> 2.5)
+  jbuilder (~> 2.9)
   letter_opener
   listen (>= 3.0.5, < 3.2)
+  mocha
   puma (~> 3.11)
   rails (~> 6.0.0.rc1)
   rubocop
@@ -276,11 +286,12 @@ DEPENDENCIES
   tzinfo-data
   web-console (>= 3.3.0)
   webdrivers
+  webmock
   webpacker (~> 4.0)
   yard
 
 RUBY VERSION
    ruby 2.6.3p62
 
 BUNDLED WITH
-   2.0.1
+   2.0.2

app/controllers/application_controller.rb

@@ -5,7 +5,6 @@ class ApplicationController < ActionController::Base
   protect_from_forgery unless: -> { request.format.json? }
 
   def authenticate
-    # rubocop:disable Metrics/LineLength
     basic_auth_username = ENV.fetch('BASIC_AUTH_USERNAME', '')
     basic_auth_password = ENV.fetch('BASIC_AUTH_PASSWORD', '')
 
@@ -14,6 +13,5 @@ def authenticate
     authenticate_or_request_with_http_basic('Ciao Application') do |username, password|
       username == basic_auth_username && password == basic_auth_password
     end
-    # rubocop:enable Metrics/LineLength
   end
 end

app/lib/ciao/notifications/base.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module Ciao
+  module Notifications
+    class Base
+      def initialize(endpoint = nil,
+                     payload_template = nil,
+                     payload_renderer_cls = Ciao::Renderers::ReplaceRenderer)
+        @endpoint = endpoint
+        @payload_renderer = payload_renderer_cls.new(payload_template)
+      end
+
+      def notify(_payload_data = {})
+        raise NotImplementedError,
+              'You can not call Ciao::Notifications::Base#notify directly'
+      end
+    end
+  end
+end

app/lib/ciao/notifications/mail_notification.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module Ciao
+  module Notifications
+    class MailNotification < Base
+      def notify(payload_data = {})
+        CheckMailer.with(payload_data).change_status_mail.deliver
+      end
+    end
+  end
+end

app/lib/ciao/notifications/webhook_notification.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module Ciao
+  module Notifications
+    class WebhookNotification < Base
+      def notify(payload_data = {})
+        uri = URI.parse(@endpoint)
+        http = Net::HTTP.new(uri.host, uri.port)
+        http.use_ssl = uri.scheme == 'https'
+
+        request = Net::HTTP::Post.new(
+          uri.request_uri,
+          'Content-Type' => 'application/json'
+        )
+        request.body = @payload_renderer.render(payload_data)
+        http.request(request)
+      rescue *NET_HTTP_ERRORS => e
+        Rails.logger.error "Ciao::Notifications::WebhookNotification#notify Could not notify webhook(#{@endpoint}) - #{e}"
+      end
+    end
+  end
+end

app/lib/ciao/parsers/webhook_parser.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module Ciao
+  module Parsers
+    class WebhookParser
+      WEBHOOKS_ENDPOINT_PREFIX = 'CIAO_WEBHOOK_ENDPOINT_'
+      WEBHOOKS_PAYLOAD_PREFIX = 'CIAO_WEBHOOK_PAYLOAD_'
+
+      WEBHOOKS_ENDPOINT_FORMAT = "#{WEBHOOKS_ENDPOINT_PREFIX}%s"
+      WEBHOOKS_PAYLOAD_FORMAT = "#{WEBHOOKS_PAYLOAD_PREFIX}%s"
+
+      WEBHOOKS_FORMAT_REGEX = /^#{WEBHOOKS_ENDPOINT_PREFIX}(?<name>[A-Z0-9_]+)$/.freeze
+
+      def self.webhooks
+        names.map do |check_name|
+          {
+            endpoint: ENV.fetch(WEBHOOKS_ENDPOINT_FORMAT % check_name, ''),
+            payload: ENV.fetch(WEBHOOKS_PAYLOAD_FORMAT % check_name, '')
+          }
+        end
+      end
+
+      def self.names
+        matches.map { |match| match[:name] }
+      end
+
+      def self.matches
+        ENV.map do |k, _v|
+          k.match(WEBHOOKS_FORMAT_REGEX)
+        end.compact
+      end
+    end
+  end
+end

app/lib/ciao/renderers/base.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module Ciao
+  module Renderers
+    class Base
+      def initialize(template)
+        @template = template
+      end
+
+      def render(_data)
+        raise NotImplementedError,
+              'You can not call Ciao::Renderers::Base#render directly'
+      end
+    end
+  end
+end

app/lib/ciao/renderers/replace_renderer.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Ciao
+  module Renderers
+    class ReplaceRenderer < Base
+      CHECK_NAME_PLACEHOLDER = '__name__'
+      STATUS_AFTER_PLACEHOLDER = '__status_after__'
+      STATUS_BEFORE_PLACEHOLDER = '__status_before__'
+      URL_PLACEHOLDER = '__url__'
+      CHECK_URL_PLACEHOLDER = '__check_url__'
+
+      def render(data)
+        return '' if @template.nil?
+
+        @template
+          .gsub(CHECK_NAME_PLACEHOLDER, data.fetch(:name, '').to_s)
+          .gsub(STATUS_AFTER_PLACEHOLDER, data.fetch(:status_after, '').to_s)
+          .gsub(STATUS_BEFORE_PLACEHOLDER, data.fetch(:status_before, '').to_s)
+          .gsub(URL_PLACEHOLDER, data.fetch(:url, '').to_s)
+          .gsub(CHECK_URL_PLACEHOLDER, data.fetch(:check_url, '').to_s)
+      end
+    end
+  end
+end

app/models/check.rb

@@ -42,7 +42,6 @@ def self.percentage_healthy
   end
 
   def create_job
-    # rubocop:disable Metrics/LineLength
     job =
       Rufus::Scheduler.singleton.cron cron, job: true do
         url = URI.parse(self.url)
@@ -62,8 +61,16 @@ def create_job
           status_after = self.status
         end
         if status_before != status_after
-          CheckMailer.with(name: name, status_before: status_before, status_after: status_after).change_status_mail.deliver
-          Rails.logger.info "ciao-scheduler Sent 'changed_status' notification mail"
+          Rails.logger.info "ciao-scheduler Check '#{name}': Status changed from '#{status_before}' to '#{status_after}'"
+          NOTIFICATIONS.each do |notification|
+            notification.notify(
+              name: name,
+              status_before: status_before,
+              status_after: status_after,
+              url: url,
+              check_url: Rails.application.routes.url_helpers.check_path(self)
+            )
+          end
         end
       end
     if job
@@ -73,7 +80,6 @@ def create_job
       Rails.logger.error 'ciao-scheduler Could not create job'
     end
     job
-    # rubocop:enable Metrics/LineLength
   end
 
   def unschedule_job

bin/bundle

@@ -28,7 +28,7 @@ m = Module.new do
     bundler_version = nil
     update_index = nil
     ARGV.each_with_index do |a, i|
-      if update_index && update_index.succ == i && a =~ Gem::Version::ANCHORED_VERSION_PATTERN
+      if update_index && update_index.succ == i && a =~ Gem::Version::ANCHORED_VERSION_PATTERN # rubocop:disable Style/IfUnlessModifier
         bundler_version = a
       end
       next unless a =~ /\A--bundler(?:[= ](#{Gem::Version::VERSION_PATTERN}))?\z/
@@ -79,7 +79,7 @@ m = Module.new do
   end
 
   def activate_bundler(bundler_version)
-    if Gem::Version.correct?(bundler_version) && Gem::Version.new(bundler_version).release < Gem::Version.new('2.0')
+    if Gem::Version.correct?(bundler_version) && Gem::Version.new(bundler_version).release < Gem::Version.new('2.0') # rubocop:disable Style/IfUnlessModifier
       bundler_version = '< 2'
     end
     gem_error = activation_error_handling do

config/initializers/create_background_jobs.rb

@@ -2,6 +2,7 @@
 
 # Create all Rufus Scheduler Jobs for active checks on Application Start
 # Prevent the initializer to be run during rake tasks
-if defined?(Rails::Server) && ActiveRecord::Base.connection.table_exists?('checks')
+
+if defined?(Rails::Server) && ActiveRecord::Base.connection.table_exists?('checks') # rubocop:disable Style/IfUnlessModifier
   Check.active.each(&:create_job)
 end

config/initializers/notifications.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+# Some time in the future Rails is not going to auto_load these for us :(
+# we have to explictly require it here
+Dir[Rails.root.join('app', 'lib', 'ciao', '**', '*.rb')].each { |f| require f }
+
+# export CIAO_WEBHOOK_ENDPOINT_$NAME=https://chat.yourhost.net/*****
+# export CIAO_WEBHOOK_PAYLOAD_$NAME=#'{"username":"Brot & Games","icon_url":"https://avatars0.githubusercontent.com/u/43862266?s=400&v=4","text":"Example message","attachments":[{"title":"Rocket.Chat","title_link":"https://rocket.chat","text":"Rocket.Chat, the best open source chat","image_url":"/images/integration-attachment-example.png","color":"#764FA5"}]}'
+# `$NAME` can be any word `[A-Z0-9_]+` and must be unique as it is used as an identifier
+
+NOTIFICATIONS = Ciao::Parsers::WebhookParser.webhooks.map do |webhook|
+  Ciao::Notifications::WebhookNotification.new(
+    webhook[:endpoint],
+    webhook[:payload],
+    Ciao::Renderers::ReplaceRenderer
+  )
+end
+
+NOTIFICATIONS << Ciao::Notifications::MailNotification.new if ENV['SMTP_ADDRESS'].present?

test/test_helper.rb

@@ -3,6 +3,8 @@
 ENV['RAILS_ENV'] ||= 'test'
 require_relative '../config/environment'
 require 'rails/test_help'
+require 'mocha/minitest'
+require 'webmock/minitest'
 
 module ActiveSupport
   class TestCase