Class: Vanagon::Engine::Docker

Inherits:
Base
  • Object
show all
Defined in:
lib/vanagon/engine/docker.rb

Instance Attribute Summary

Attributes inherited from Base

#remote_workdir, #target

Instance Method Summary collapse

Methods inherited from Base

#dispatch, #get_remote_workdir, #retrieve_built_artifact, #setup, #ship_workdir, #startup, #validate_platform

Constructor Details

#initialize(platform, target = nil, **opts) ⇒ Docker

Both the docker_image and the docker command itself are required for the docker engine to work



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# File 'lib/vanagon/engine/docker.rb', line 8

def initialize(platform, target = nil, **opts)
  super

  @docker_cmd = Vanagon::Utilities.find_program_on_path('docker')
  @required_attributes << "docker_image"
end

Instance Method Details

#build_host_name ⇒ Object

Return the docker image name to build on



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# File 'lib/vanagon/engine/docker.rb', line 21

def build_host_name
  if @build_host_name.nil?
    validate_platform
    # Docker requires container names to match: [a-zA-Z0-9][a-zA-Z0-9_.-]
    # So, transform slashes and colons commonly used as separators in
    # image names.
    @build_host_name = @platform.docker_image.gsub(%r{[/:]}, '_')
  end

  @build_host_name
end

#name ⇒ Object

Get the engine name



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# File 'lib/vanagon/engine/docker.rb', line 16

def name
  'docker'
end

#select_target ⇒ Object

This method is used to obtain a vm to build upon using a docker container.

Raises:



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# File 'lib/vanagon/engine/docker.rb', line 36

def select_target # rubocop:disable Metrics/AbcSize
  extra_args = @platform.docker_run_args.nil? ? [] : @platform.docker_run_args

  Vanagon::Utilities.ex("#{@docker_cmd} run -d --name #{build_host_name}-builder -p #{@platform.ssh_port}:22 #{extra_args.join(' ')} #{@platform.docker_image}")
  @target = 'localhost'

  # Wait for ssh to come up in the container. Retry 5 times with a 1
  # second sleep between errors to account for network resets while SSHD
  # is starting. Allow a maximum of 5 seconds for SSHD to start.
  Vanagon::Utilities.retry_with_timeout(5, 5) do
    begin
      Vanagon::Utilities.remote_ssh_command("#{@target_user}@#{@target}", 'exit', @platform.ssh_port)
    rescue StandardError => e
      sleep(1) # Give SSHD some time to start.
      raise e
    end
  end
rescue StandardError => e
  raise Vanagon::Error.wrap(e, "Something went wrong getting a target vm to build on using docker. Ssh was not up in the container after 5 seconds.")
end

#teardown ⇒ Object

This method is used to tell the vmpooler to delete the instance of the vm that was being used so the pool can be replenished.



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# File 'lib/vanagon/engine/docker.rb', line 59

def teardown
  Vanagon::Utilities.ex("#{@docker_cmd} stop #{build_host_name}-builder")
  Vanagon::Utilities.ex("#{@docker_cmd} rm #{build_host_name}-builder")
rescue Vanagon::Error => e
  warn "There was a problem tearing down the docker container #{build_host_name}-builder (#{e.message})."
end