Adding Rubygem for Ruby Applications (#21)

**Why:**

* Currently tested to run a `sinatra` application
* Uses the same `mp-compiler` to build out the specs
* Uses an `alpine` image out of the box to run

Author: christopherhein

README.md

@@ -33,11 +33,13 @@ When you run this program via the `java` command or your IDE, rather than simply
 packages up the Java code in a container, and runs that container.
 
 ## What languages do you support?
+
 Currently:
    * [java](java)
    * [.NET core](dotnet)
    * [javascript](javascript) (NodeJS)
    * [go](go)
+   * [ruby](ruby)
 
 But it's fairly straightforward to add other languages, we would love to see contributions.
 
@@ -47,6 +49,7 @@ For more details see the more complete walkthroughs for each language:
    * [java tutorial](tutorials/java/tutorial.md)
    * [.NET Core tutorial](tutorials/dotnet/tutorial.md)
    * [javascript tutorial](tutorials/javascript/tutorial.md)
+   * [Ruby tutorial](tutorials/ruby/tutorial.md)
 
 ## Contribute
 There are many ways to contribute to Metaparticle

ruby/README.md

@@ -0,0 +1,60 @@
+# Metaparticle/Package for Ruby
+Metaparticle/Package is a collection of libraries intended to 
+make building and deploying containers a seamless and idiomatic
+experience for developers.
+
+This is the implementation for Ruby.
+
+## Introduction
+Metaparticle/Package simplifies and centralizes the task of
+building and deploying a container image.
+
+Here is a quick example.
+
+Consider this simple Ruby application:
+
+```ruby
+class App < Sinatra::Base
+  set :bind, '0.0.0.0'
+
+  get '/' do
+    'metaparticle from ruby!'
+  end
+end
+```
+
+To containerize this application, you need to use the `metaparticle` gem and
+the `Metaparticle::Package` wrapper class like this:
+
+```ruby
+require 'metaparticle'
+require 'sinatra/base'
+
+Metaparticle::Package.containerize(
+  {
+    name: 'sinatra-app',
+    ports: [4567],
+    replicas: 3,
+    runner: 'metaparticle',
+    repository: 'christopherhein',
+    publish: true,
+    public: true
+  }) do
+  class App < Sinatra::Base
+    set :bind, '0.0.0.0'
+
+    get '/' do
+      'metaparticle from ruby!'
+    end
+    run!
+  end
+end
+```
+
+Then when you run the ruby file it will automatically create a docker image,
+push to your registry of choice, and then use `mp-compiler` to push to your k8s
+cluster.
+
+## Tutorial
+For a more complete exploration of the Metaparticle/Package for Ruby, please see the [in-depth tutorial](../tutorials/ruby/tutorial.md).
+

ruby/examples/Dockerfile

@@ -0,0 +1,11 @@
+FROM ruby:2.4-alpine
+
+RUN mkdir -p /sinatra-app
+WORKDIR /sinatra-app
+
+COPY Gemfile /sinatra-app/
+COPY Gemfile.lock /sinatra-app/
+RUN bundle install
+
+COPY . /sinatra-app/
+CMD ruby app.rb

ruby/examples/Gemfile

@@ -0,0 +1,5 @@
+source 'https://rubygems.org'
+
+gem 'sinatra'
+# gem 'metaparticle', path: './metaparticle'
+gem 'metaparticle'

ruby/examples/Gemfile.lock

@@ -0,0 +1,24 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    metaparticle (0.0.0.13)
+    mustermann (1.0.1)
+    rack (2.0.3)
+    rack-protection (2.0.0)
+      rack
+    sinatra (2.0.0)
+      mustermann (~> 1.0)
+      rack (~> 2.0)
+      rack-protection (= 2.0.0)
+      tilt (~> 2.0)
+    tilt (2.0.8)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  metaparticle
+  sinatra
+
+BUNDLED WITH
+   1.15.4

ruby/examples/app.rb

@@ -0,0 +1,28 @@
+require 'rubygems'
+require 'metaparticle'
+require 'sinatra/base'
+
+class App < Sinatra::Base
+  set :bind, '0.0.0.0'
+
+  get '/' do
+    'metaparticle from ruby!'
+  end
+end
+
+Metaparticle::Package.containerize(
+  {
+    name: 'sinatra-app',
+    ports: [4567],
+    replicas: 3,
+    runner: 'metaparticle',
+    repository: 'christopherhein',
+    publish: true,
+    public: true,
+		# shardSpec: {
+		# 	shards: 3,
+		# 	"urlPattern": "(.*)"
+		# },
+  }) do
+  App.run!
+end

ruby/metaparticle/.gitignore

@@ -0,0 +1,12 @@
+/.bundle/
+/.yardoc
+/Gemfile.lock
+/_yardoc/
+/coverage/
+/doc/
+/pkg/
+/spec/reports/
+/tmp/
+
+# rspec failure tracking
+.rspec_status

ruby/metaparticle/.rspec

@@ -0,0 +1,2 @@
+--format documentation
+--color

ruby/metaparticle/.travis.yml

@@ -0,0 +1,5 @@
+sudo: false
+language: ruby
+rvm:
+  - 2.4.0
+before_install: gem install bundler -v 1.15.4

ruby/metaparticle/Gemfile

@@ -0,0 +1,6 @@
+source "https://rubygems.org"
+
+git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
+
+# Specify your gem's dependencies in metaparticle.gemspec
+gemspec

ruby/metaparticle/README.md

@@ -0,0 +1,62 @@
+# Metaparticle
+
+Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/metaparticle`. To experiment with that code, run `bin/console` for an interactive prompt.
+
+TODO: Delete this and the text above, and describe your gem
+
+## Installation
+
+Add this line to your application's Gemfile:
+
+```ruby
+gem 'metaparticle'
+```
+
+And then execute:
+
+    $ bundle
+
+Or install it yourself as:
+
+    $ gem install metaparticle
+
+## Usage
+
+    require 'metaparticle'
+    require 'sinatra/base'
+
+    class App < Sinatra::Base
+      set :bind, '0.0.0.0'
+
+      get '/' do
+        'metaparticle from ruby!'
+      end
+    end
+
+    Metaparticle::Package.containerize(
+      {
+        name: 'sinatra-app',
+        ports: [4567],
+        replicas: 3,
+        runner: 'metaparticle',
+        repository: 'christopherhein',
+        publish: true,
+        public: true
+      }) do
+      App.run!
+    end
+
+## Development
+
+After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
+
+To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
+
+## Contributing
+
+Bug reports and pull requests are welcome on GitHub at https://github.com/metaparticle/package.
+
+## License
+
+The gem is available as open source under the terms of the [MIT License](http://opensource.org/licenses/MIT).
+

ruby/metaparticle/Rakefile

@@ -0,0 +1,6 @@
+require "bundler/gem_tasks"
+require "rspec/core/rake_task"
+
+RSpec::Core::RakeTask.new(:spec)
+
+task :default => :spec

ruby/metaparticle/lib/metaparticle.rb

@@ -0,0 +1,5 @@
+require "metaparticle/version"
+require 'metaparticle/package'
+
+module Metaparticle
+end

ruby/metaparticle/lib/metaparticle/docker.rb

@@ -0,0 +1,26 @@
+module Metaparticle
+  class Docker
+    def in_docker_container?
+      if ENV['METAPARTICLE_IN_CONTAINER'] == "true"
+        return true
+      end
+
+      # Using same hack to work on macOS
+      begin
+        info = File.readlines('/proc/1/cgroup')
+
+        # horribly ineffient, can do this better
+        if !info.select {|line| line =~ /docker/}.empty?
+          return true
+        end
+        if !info.select {|line| line =~ /kubepods/}.empty?
+          return true
+        end
+      rescue
+        return false
+      end
+
+      return false
+    end
+  end
+end

ruby/metaparticle/lib/metaparticle/docker_builder.rb

@@ -0,0 +1,15 @@
+module Metaparticle
+  class DockerBuilder
+    def initialize(config)
+      @config = config
+    end
+
+    def build
+      `docker build -t #{@config.image} .`
+    end
+
+    def push
+      `docker push #{@config.image}`
+    end
+  end
+end

ruby/metaparticle/lib/metaparticle/docker_runner.rb

@@ -0,0 +1,16 @@
+module Metaparticle
+  class DockerRunner
+    def initialize(config)
+      @config = config
+    end
+
+    def run
+      `docker run -it --name #{@config.name} #{port_string} #{@config.image}`
+    end
+
+    private
+    def port_string
+      @port_string = @config.ports.map {|port| "-p #{port}:#{port}" }.join(" ")
+    end
+  end
+end

ruby/metaparticle/lib/metaparticle/metaparticle_runner.rb

@@ -0,0 +1,49 @@
+require 'fileutils'
+
+module Metaparticle
+  class MetaparticleRunner
+    def initialize(config)
+      @config = config
+    end
+
+    def run
+      options = {
+        name: @config.name,
+        guid: 1234567,
+        services: [
+          {
+            name: @config.name,
+            replicas: @config.replicas,
+            shardSpec: @config.shardSpec,
+            containers: [
+              {
+                image: @config.image
+              }
+            ],
+            ports: @config.ports.map {|p| {number: p}}
+          }
+        ],
+        serve: {
+          name: @config.name
+        }
+      }
+      if @config.public
+        options[:serve][:public] = true
+      end
+
+      create_directory
+
+      File.open(".metaparticle/service.json", "w") do |f|
+        f.write(options.compact!.to_json)
+      end
+
+      `mp-compiler -f .metaparticle/service.json`
+      `mp-compiler -f .metaparticle/service.json --deploy=false --attach=true`
+    end
+
+    private
+    def create_directory
+      FileUtils::mkdir_p('.metaparticle')
+    end
+  end
+end