Plugins » Docker

module Service

  class RegistryApi

    DOCKER_HUB = 'https://index.docker.io/'.freeze

    DEFAULTS = {

      url: 'http://localhost:5000'.freeze,

      connection: { omit_default_port: true,

                    headers: { "Content-Type" => "application/json" }

                  }

    }

    attr_accessor :config, :url

    delegate :logger, :to => Rails

    def initialize(params = {})

      self.config = DEFAULTS.merge(params)

      self.url = config[:url]

      Docker.logger = logger if Rails.env.development? || Rails.env.test?

    end

    def connection

      @connection ||= ::Docker::Connection.new(url, default_connection_options.merge(credentials))

    end

    def get(path, params = nil)

      response = connection.get('/'.freeze, params,

                                connection.options.merge({ path: "#{path}" }))

      response = parse_json(response)

      response

    end

    # Since the Registry API v2 does not support a search the v1 endpoint is used

    # Newer registries will fail, the v2 catalog endpoint is used

    def search(query)

      get('/v1/search'.freeze, { q: query })

    rescue => e

      logger.warn "API v1 - Search failed #{e.backtrace}"

      { 'results' => catalog(query) }

    end

    # Some Registries might have this endpoint not implemented/enabled

    def catalog(query)

      get('/v2/_catalog'.freeze)['repositories'].select do |image|

        image =~ /^#{query}/

      end.map { |image_name| { 'name' => image_name } }

    end

    def tags(image_name, query = nil)

      result = get_tags(image_name)

      result = result.keys.map { |t| {'name' => t.to_s } } if result.is_a? Hash

      result = filter_tags(result, query) if query

      result

    end

    def ok?

      get('/v1/'.freeze).match("Docker Registry API")

    rescue => e

      logger.warn "API v1 - Ping failed #{e.backtrace}"

      get('/v2/'.freeze).is_a? Hash

    end

    def self.docker_hub

      @@docker_hub ||= new(url: DOCKER_HUB)

    end

    private

    def default_connection_options

      @default_connection_options ||= DEFAULTS[:connection].tap do |defaults|

        defaults[:ssl_verify_peer] = config.fetch(:verify_ssl, true)

      end

    end

    def parse_json(string)

      JSON.parse(string)

    rescue => e

      logger.warn "JSON parsing failed: #{e.backtrace}"

      string

    end

    def get_tags(image_name)

      get("/v1/repositories/#{image_name}/tags")

    rescue => e

      Foreman::Logging.exception("API v1 - Repository images request failed", e)

      tags_v2(image_name)

    end

    def tags_v2(image_name)

      get("/v2/#{image_name}/tags/list")['tags'].map { |tag| { 'name' => tag } }

    rescue Docker::Error::NotFoundError

      []

    rescue Excon::Error::Found => e

      if e.response.status == 302

        new_path = URI.parse(e.response.headers['Location']).path

        get(new_path)['tags'].map { |tag| { 'name' => tag } }

      else

        ::Foreman.exception "Could not load tags using v2", e

        []

      end

    end

    def credentials

      { user: config.fetch(:user, nil),

        password: config.fetch(:password, nil) }

    end

    def filter_tags(result, query)

      result.select do |tag_name|

        tag_name['name'] =~ /^#{query}/

      end

    end

  end

end