helix_web_services.rb #6

require 'auth'
require 'config'
require 'hws_p4_cleanup'
require 'hws_helpers'
require 'hws_settings'
require 'helix_sync'
require 'helix_web_services/version'
require 'helix_versioning_engine'
require 'projects'
require 'rack/parser'
require 'sinatra/base'
require 'sinatra/namespace'

require 'git_fusion_strings'
require 'P4'

module HelixWebServices
  module ErrorHandling
    def self.registered(app)
      # Always invoke our error handlers.
      app.set :raise_errors => false
      app.set :show_exceptions => false
      app.set :dump_errors => true

      app.error do |err|
        err = env['sinatra.error']

        if err.is_a?(P4Exception)
          # Can happen when we're not passing a block to
          # open_p4. Convert to a P4WebAPI error. This is not ideal
          # as it always uses the same code, but then we have no idea
          # what actually happened here.

          err = P4Error.default_error(err.to_s)

          # Fall through...
        end

        body = nil

        if err.is_a?(P4Error)
          if err.message_code == 7480 || err.message_code == 7189
            halt 401, {
                        MessageCode: 0,
                        MessageSeverity: 4,
                        MessageText: 'Resource not found'
                    }.to_json
          else
            code = 500
            code = 400 if err.user_error?
            halt code, {
                         MessageCode: err.message_code,
                         MessageSeverity: err.message_severity,
                         MessageText: err.message_text
                     }.to_json
          end
        end

        if body.nil?
          body = {
              MessageCode: 15_361,
              MessageSeverity: P4::E_FATAL,
              MessageText: 'Unknown server issue'
          }.to_json
        end

        halt 500, body
      end
    end
  end

  # A master Sinatra instance that basically sets up routing to each of the
  # sub-applications, and connects the authorization mechanism.
  #
  # In the future, we may have status and health check functionality available
  # here.
  #
  # We mount each application under a "versioned" subpath. This allows us to
  # keep an old and new version of a sub-application in the system at the
  # same time, ideally to allow for migration to breaking changes.
  class Master < Sinatra::Base
    register Sinatra::Namespace
    register HelixWebServices::ErrorHandling

    # Without this set, the return content type is always text/html
    before do
      content_type 'application/json'
    end

    # Inject Rack::Parser into the middleware stack so that it
    # automatically parses json bodies in post requests into the params
    # array.
    use Rack::Parser,
        content_types: {
            'application/json' => proc { |body| ::MultiJson.decode body }
        }

    use HWSSettings

    use HWSP4Cleanup

    use Auth::Middleware,
        unauthenticated_paths: [
            {method: 'POST', path: '/projects/v1/login'},
            {method: 'POST', path: /p4\/v(\d*)\/login/},
            {method: 'GET', path: '/status'}
        ]

    not_found do
      status 404
      ''
    end

    class << self
      def register_app(app)
        use app
        app.register HelixWebServices::ErrorHandling
        app.before do
          content_type 'application/json'
          headers['X-Helix-Web-Services-Version'] = HelixWebServices::PRODUCT_ID
        end
        app.helpers HWSHelpers
        app.not_found do
          status 404
          ''
        end
      end
    end

    get '/status' do
      {'status'=>'OK'}.to_json
    end

    register_app(Config::App)
    register_app(HelixVersioningEngine::App)
    register_app(Projects::App)
    if HWSSettings.system.ENABLE_GIT_FUSION
      require 'git_fusion'
      register_app(GitFusion::App)
    end
    register_app(HelixSync::App)

    # This is special method to inject custom middleware after you know the
    # per-request settings have been initialized.
    def self.use_after_settings(middleware, *args, &block)
      @prototype = nil
      settings_index = @middleware.index { |m| m.first == HWSSettings }
      @middleware.insert settings_index + 1, [middleware, args, block]
    end
  end
end

# We offer a special path in our settings where we'll load up any scripts
# and require them.
scripts_dir = ENV['CUSTOM_SCRIPTS'] || HWSSettings.system.CUSTOM_SCRIPTS
if Dir.exist?(scripts_dir)
  $LOAD_PATH << scripts_dir
  Dir.glob("#{scripts_dir}/*.rb").each do |s|
    require s
  end
end