A Rakefile to manage dev instances using Docker, boot2docker, and fig for configuration management.

Rakefile

namespace :boot2docker do
  desc 'Start VM from any states'
  task :start do
    %x(boot2docker start > /dev/null 2>&1)
  end

  desc 'Setup shell'
  task :shellinit => [:start] do
    # NOTE: this does not set the env, so we have to do something different
    # %x($(boot2docker shellinit > /dev/null 2>&1))
    env = %x(boot2docker shellinit 2> /dev/null)
    env.split(/\n/).each do |line|
      env, setting = line.gsub(/^.* /, '').split(/\=/)
      ENV[env] = setting
    end
  end

  desc 'Gracefully shutdown the VM'
  task :stop do
    %x(boot2docker stop)
  end

  desc 'Install nsenter'
  task :install_nsenter => [:shellinit] do
    system("boot2docker ssh '[ -f /var/lib/boot2docker/nsenter ] || docker run --rm -v /var/lib/boot2docker/:/target jpetazzo/nsenter'")
  end

  desc 'SSH into the given container'
  task :ssh, [:container] => :install_nsenter do |t, args|
    container_hash = %x(docker ps | grep #{args[:container]} | awk '{ print $1 }')
    puts "SSH into container: #{container_hash}"
    exec "boot2docker ssh -t sudo /var/lib/boot2docker/docker-enter #{container_hash}"
  end
end

namespace :docker do
  namespace :maintenance do
    desc 'Stop running containers'
    task :stop, [:container] => 'boot2docker:shellinit' do |t, args|
      # rake docker:maintenance:stop[foo]
      if args[:container]
        puts "Stopping #{args[:container]}"
        %x(docker ps -a | grep #{args[:container]} | awk '{print $1}' | xargs docker stop)
      else
        puts "Stopping ALL"
        %x(docker stop $(docker ps -aq))
      end
    end

    desc 'Remove one or more containers'
    task :rm, [:container] => [:stop] do |t, args|
      if args[:container]
        puts "Removing #{args[:container]}"
        %x(docker ps -a | grep #{args[:container]} | awk '{print $1}' | xargs docker rm)
      else
        puts "Removing ALL"
        %x(docker rm $(docker ps -aq))
      end
    end

    desc 'Remove one or more images'
    task :rmi, [:container] => [:stop, :rm] do |t, args|
      %x(docker rmi $(docker images -a | grep "^<none>" | awk '{print $3}') > /dev/null 2>&1)
    end
  end

  namespace :fig do
    desc 'Use fig to build the Dockerfile image'
    task :build => ['boot2docker:shellinit'] do
      ENV['FIG_PROJECT_NAME'] = File.dirname(__FILE__).split(/\//).last.downcase
      system "fig build"
    end

    desc 'Use fig to run the app as described in fig.yml'
    # TODO: clean out old images
    task :up => :build do
      system "fig up"
    end
  end

  namespace :info do
    desc 'List all the container (docker ps -a)'
    task :ps => 'boot2docker:shellinit' do
      system("docker ps -a")
    end

    desc 'List all the images on localhost (docker images)'
    task :images => 'boot2docker:shellinit' do
      system("docker images")
    end

    # rake docker:hostname[rails-basic-app,3000]
    # open $(rake docker:info:hostname[railsbasic_web_1,3000])
    desc 'Give the hostname and port for a container'
    task :hostname, [:container, :port] => 'boot2docker:shellinit' do |t, args|
      require 'json'
      docker_host = ENV['DOCKER_HOST'].match(/\/(\d*.\d*.\d*.\d*):/).to_a.last
      json        = JSON.parse(%x(docker inspect #{args[:container]})).first
      if json["NetworkSettings"]["Ports"]
        port        = args[:port]
        host_port   = json["NetworkSettings"]["Ports"]["#{port}/tcp"].first["HostPort"]
        puts "http://#{docker_host}:#{host_port}"
      else
        puts "No docker container instance found for #{args[:container]}"
      end
    end
  end
end

namespace :git do
  desc 'Stash files'
  task :stash do
    %x(git stash save)
  end

  desc 'Pull the freshest code'
  task :pull, [:remote, :branch] do |t, args|
    # NOTE: when used as a dependency this is pretty sloppy
    remote = args[:remote] || 'origin'
    branch = args[:branch] || 'master'
    %x(git pull --rebase #{remote} #{branch})
  end
end

task :default => 'docker:fig:up'

__END__