Add elixir support

compiled_starters/elixir/.codecrafters/compile.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+#
+# This script is used to compile your program on CodeCrafters
+#
+# This runs before .codecrafters/run.sh
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit on failure
+
+# (This file is empty since Elixir programs don't use a compile step)

compiled_starters/elixir/.codecrafters/run.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+#
+# This script is used to run your program on CodeCrafters
+#
+# This runs after .codecrafters/compile.sh
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit on failure
+
+exec mix run --no-halt -- "$@"

compiled_starters/elixir/.formatter.exs

@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

compiled_starters/elixir/.gitattributes

@@ -0,0 +1 @@
+* text=auto

compiled_starters/elixir/.gitignore

@@ -0,0 +1,24 @@
+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+app-*.tar
+

compiled_starters/elixir/README.md

@@ -0,0 +1,34 @@
+![progress-banner](https://codecrafters.io/landing/images/default_progress_banners/kafka.png)
+
+This is a starting point for Elixir solutions to the
+["Build Your Own Kafka" Challenge](https://codecrafters.io/challenges/kafka).
+
+In this challenge, you'll build a toy Kafka clone that's capable of accepting
+and responding to APIVersions & Fetch API requests. You'll also learn about
+encoding and decoding messages using the Kafka wire protocol. You'll also learn
+about handling the network protocol, event loops, TCP sockets and more.
+
+**Note**: If you're viewing this repo on GitHub, head over to
+[codecrafters.io](https://codecrafters.io) to try the challenge.
+
+# Passing the first stage
+
+The entry point for your Kafka implementation is in `lib/server.ex`. Study and
+uncomment the relevant code, and push your changes to pass the first stage:
+
+```sh
+git commit -am "pass 1st stage" # any msg
+git push origin master
+```
+
+That's all!
+
+# Stage 2 & beyond
+
+Note: This section is for stages 2 and beyond.
+
+1. Ensure you have `mix` installed locally
+1. Run `./your_program.sh` to run your Kafka broker, which is implemented in
+   `lib/server.ex`.
+1. Commit your changes and run `git push origin master` to submit your solution
+   to CodeCrafters. Test output will be streamed to your terminal.

compiled_starters/elixir/codecrafters.yml

@@ -0,0 +1,11 @@
+# Set this to true if you want debug logs.
+#
+# These can be VERY verbose, so we suggest turning them off
+# unless you really need them.
+debug: false
+
+# Use this to change the Elixir version used to run your code
+# on Codecrafters.
+#
+# Available versions: elixir-1.17
+language_pack: elixir-1.17

compiled_starters/elixir/lib/server.ex

@@ -0,0 +1,26 @@
+defmodule Server do
+  @moduledoc """
+  Your implementation of a Kafka broker
+  """
+
+  use Application
+
+  def start(_type, _args) do
+    Supervisor.start_link([{Task, fn -> Server.listen() end}], strategy: :one_for_one)
+  end
+
+  @doc """
+  Listen for incoming connections
+  """
+  def listen() do
+    # You can use print statements as follows for debugging, they'll be visible when running tests.
+    IO.puts("Logs from your program will appear here!")
+
+    # Uncomment this block to pass the first stage
+    #
+    # # Since the tester restarts your program quite often, setting SO_REUSEADDR
+    # # ensures that we don't run into 'Address already in use' errors
+    # {:ok, socket} = :gen_tcp.listen(9092, [:binary, active: false, reuseaddr: true])
+    # {:ok, _client} = :gen_tcp.accept(socket)
+  end
+end

compiled_starters/elixir/mix.exs

@@ -0,0 +1,20 @@
+defmodule App.MixProject do
+  # NOTE: You do not need to change anything in this file.
+  use Mix.Project
+
+  def project do
+    [
+      app: :kafka,
+      version: "1.0.0",
+      elixir: "~> 1.10",
+      start_permanent: Mix.env() == :prod
+    ]
+  end
+
+  def application do
+    [
+      extra_applications: [:logger],
+      mod: {Server, []}
+    ]
+  end
+end

compiled_starters/elixir/your_program.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+#
+# Use this script to run your program LOCALLY.
+#
+# Note: Changing this script WILL NOT affect how CodeCrafters runs your program.
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit early if any commands fail
+
+# Copied from .codecrafters/run.sh
+#
+# - Edit this to change how your program runs locally
+# - Edit .codecrafters/run.sh to change how your program runs remotely
+exec mix run --no-halt -- "$@"

course-definition.yml

@@ -21,6 +21,9 @@ languages:
   - slug: "javascript"
   - slug: "python"
   - slug: "rust"
+  - slug: "elixir"
+    release_status: "alpha"
+    alpha_tester_usernames: ["hlorellium"]
 
 marketing:
   difficulty: medium

dockerfiles/elixir-1.17.Dockerfile

@@ -0,0 +1,17 @@
+# syntax=docker/dockerfile:1.7-labs
+FROM elixir:1.17.2-alpine
+
+# Ensures the container is re-built if dependency files change
+ENV CODECRAFTERS_DEPENDENCY_FILE_PATHS="mix.exs"
+
+WORKDIR /app
+
+# .git & README.md are unique per-repository. We ignore them on first copy to prevent cache misses
+COPY --exclude=.git --exclude=README.md . /app
+
+# Install & cache deps
+RUN .codecrafters/compile.sh
+
+# If _build directory exists, move it to /app-cached
+RUN mkdir -p /app-cached
+RUN if [ -d "/app/_build" ]; then mv /app/_build /app-cached; fi

solutions/elixir/01-vi6/code/.codecrafters/compile.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+#
+# This script is used to compile your program on CodeCrafters
+#
+# This runs before .codecrafters/run.sh
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit on failure
+
+# (This file is empty since Elixir programs don't use a compile step)

solutions/elixir/01-vi6/code/.codecrafters/run.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+#
+# This script is used to run your program on CodeCrafters
+#
+# This runs after .codecrafters/compile.sh
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit on failure
+
+exec mix run --no-halt -- "$@"

solutions/elixir/01-vi6/code/.formatter.exs

@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

solutions/elixir/01-vi6/code/.gitattributes

@@ -0,0 +1 @@
+* text=auto

solutions/elixir/01-vi6/code/.gitignore

@@ -0,0 +1,24 @@
+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+app-*.tar
+

solutions/elixir/01-vi6/code/README.md

@@ -0,0 +1,34 @@
+![progress-banner](https://codecrafters.io/landing/images/default_progress_banners/kafka.png)
+
+This is a starting point for Elixir solutions to the
+["Build Your Own Kafka" Challenge](https://codecrafters.io/challenges/kafka).
+
+In this challenge, you'll build a toy Kafka clone that's capable of accepting
+and responding to APIVersions & Fetch API requests. You'll also learn about
+encoding and decoding messages using the Kafka wire protocol. You'll also learn
+about handling the network protocol, event loops, TCP sockets and more.
+
+**Note**: If you're viewing this repo on GitHub, head over to
+[codecrafters.io](https://codecrafters.io) to try the challenge.
+
+# Passing the first stage
+
+The entry point for your Kafka implementation is in `lib/server.ex`. Study and
+uncomment the relevant code, and push your changes to pass the first stage:
+
+```sh
+git commit -am "pass 1st stage" # any msg
+git push origin master
+```
+
+That's all!
+
+# Stage 2 & beyond
+
+Note: This section is for stages 2 and beyond.
+
+1. Ensure you have `mix` installed locally
+1. Run `./your_program.sh` to run your Kafka broker, which is implemented in
+   `lib/server.ex`.
+1. Commit your changes and run `git push origin master` to submit your solution
+   to CodeCrafters. Test output will be streamed to your terminal.

solutions/elixir/01-vi6/code/codecrafters.yml

@@ -0,0 +1,11 @@
+# Set this to true if you want debug logs.
+#
+# These can be VERY verbose, so we suggest turning them off
+# unless you really need them.
+debug: false
+
+# Use this to change the Elixir version used to run your code
+# on Codecrafters.
+#
+# Available versions: elixir-1.17
+language_pack: elixir-1.17

solutions/elixir/01-vi6/code/lib/server.ex

@@ -0,0 +1,21 @@
+defmodule Server do
+  @moduledoc """
+  Your implementation of a Kafka broker
+  """
+
+  use Application
+
+  def start(_type, _args) do
+    Supervisor.start_link([{Task, fn -> Server.listen() end}], strategy: :one_for_one)
+  end
+
+  @doc """
+  Listen for incoming connections
+  """
+  def listen() do
+    # Since the tester restarts your program quite often, setting SO_REUSEADDR
+    # ensures that we don't run into 'Address already in use' errors
+    {:ok, socket} = :gen_tcp.listen(9092, [:binary, active: false, reuseaddr: true])
+    {:ok, _client} = :gen_tcp.accept(socket)
+  end
+end

solutions/elixir/01-vi6/code/mix.exs

@@ -0,0 +1,20 @@
+defmodule App.MixProject do
+  # NOTE: You do not need to change anything in this file.
+  use Mix.Project
+
+  def project do
+    [
+      app: :kafka,
+      version: "1.0.0",
+      elixir: "~> 1.10",
+      start_permanent: Mix.env() == :prod
+    ]
+  end
+
+  def application do
+    [
+      extra_applications: [:logger],
+      mod: {Server, []}
+    ]
+  end
+end

solutions/elixir/01-vi6/code/your_program.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+#
+# Use this script to run your program LOCALLY.
+#
+# Note: Changing this script WILL NOT affect how CodeCrafters runs your program.
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit early if any commands fail
+
+# Copied from .codecrafters/run.sh
+#
+# - Edit this to change how your program runs locally
+# - Edit .codecrafters/run.sh to change how your program runs remotely
+exec mix run --no-halt -- "$@"

solutions/elixir/01-vi6/diff/lib/server.ex.diff

@@ -0,0 +1,31 @@
+@@ -1,26 +1,21 @@
+ defmodule Server do
+   @moduledoc """
+   Your implementation of a Kafka broker
+   """
+
+   use Application
+
+   def start(_type, _args) do
+     Supervisor.start_link([{Task, fn -> Server.listen() end}], strategy: :one_for_one)
+   end
+
+   @doc """
+   Listen for incoming connections
+   """
+   def listen() do
+-    # You can use print statements as follows for debugging, they'll be visible when running tests.
+-    IO.puts("Logs from your program will appear here!")
+-
+-    # Uncomment this block to pass the first stage
+-    #
+-    # # Since the tester restarts your program quite often, setting SO_REUSEADDR
+-    # # ensures that we don't run into 'Address already in use' errors
+-    # {:ok, socket} = :gen_tcp.listen(9092, [:binary, active: false, reuseaddr: true])
+-    # {:ok, _client} = :gen_tcp.accept(socket)
++    # Since the tester restarts your program quite often, setting SO_REUSEADDR
++    # ensures that we don't run into 'Address already in use' errors
++    {:ok, socket} = :gen_tcp.listen(9092, [:binary, active: false, reuseaddr: true])
++    {:ok, _client} = :gen_tcp.accept(socket)
+   end
+ end