Don't load all of GitLab in mail_room

Fixes #12731

CHANGELOG

@@ -3,6 +3,7 @@ Please view this file on the master branch, on stable branches it's out of date.
 v 8.6.0 (unreleased)
   - Improve the formatting for the user page bio (Connor Shea)
   - Fix avatar stretching by providing a cropping feature (Johann Pardanaud)
+  - Don't load all of GitLab in mail_room
 
 v 8.5.1
   - Fix group projects styles

config/initializers/1_settings.rb

@@ -208,10 +208,6 @@ Settings.gitlab_ci['builds_path']           = File.expand_path(Settings.gitlab_c
 #
 Settings['incoming_email'] ||= Settingslogic.new({})
 Settings.incoming_email['enabled'] = false if Settings.incoming_email['enabled'].nil?
-Settings.incoming_email['port']       = 143 if Settings.incoming_email['port'].nil?
-Settings.incoming_email['ssl']        = false if Settings.incoming_email['ssl'].nil?
-Settings.incoming_email['start_tls']  = false if Settings.incoming_email['start_tls'].nil?
-Settings.incoming_email['mailbox']    = "inbox" if Settings.incoming_email['mailbox'].nil?
 
 #
 # Build Artifacts

config/mail_room.yml

 :mailboxes:
 <%
-require_relative 'config/environment.rb'
+require "yaml"
+require "json"
 
-if Gitlab::IncomingEmail.enabled? 
-  config = Gitlab::IncomingEmail.config
+rails_env = ENV["RAILS_ENV"] || ENV["RACK_ENV"] || "development"
 
+config_file = ENV["MAIL_ROOM_GITLAB_CONFIG_FILE"] || "config/gitlab.yml"
+if File.exists?(config_file)
+  all_config = YAML.load_file(config_file)[rails_env]
+
+  config = all_config["incoming_email"] || {}
+  config['enabled']    = false    if config['enabled'].nil?
+  config['port']       = 143      if config['port'].nil?
+  config['ssl']        = false    if config['ssl'].nil?
+  config['start_tls']  = false    if config['start_tls'].nil?
+  config['mailbox']    = "inbox"  if config['mailbox'].nil?
+
+  if config['enabled'] && config['address'] && config['address'].include?('%{key}')
     redis_config_file = "config/resque.yml"
     redis_url =
       if File.exists?(redis_config_file)
-      YAML.load_file(redis_config_file)[Rails.env]
+        YAML.load_file(redis_config_file)[rails_env]
       else
         "redis://localhost:6379"
       end
     %>
     -
-    :host: <%= config.host.to_json %>
-    :port: <%= config.port.to_json %>
-    :ssl: <%= config.ssl.to_json %>
-    :start_tls: <%= config.start_tls.to_json %>
-    :email: <%= config.user.to_json %>
-    :password: <%= config.password.to_json %>
+      :host: <%= config['host'].to_json %>
+      :port: <%= config['port'].to_json %>
+      :ssl: <%= config['ssl'].to_json %>
+      :start_tls: <%= config['start_tls'].to_json %>
+      :email: <%= config['user'].to_json %>
+      :password: <%= config['password'].to_json %>
 
-    :name: <%= config.mailbox.to_json %>
+      :name: <%= config['mailbox'].to_json %>
 
       :delete_after_delivery: true
 
@@ -36,4 +48,5 @@ if Gitlab::IncomingEmail.enabled?
       :arbitration_options:
         :redis_url: <%= redis_url.to_json %>
         :namespace: mail_room:gitlab
+  <% end %>
 <% end %>

spec/config/mail_room_spec.rb

+require "spec_helper"
+
+describe "mail_room.yml" do
+  let(:config_path)   { "config/mail_room.yml" }
+  let(:configuration) { YAML.load(ERB.new(File.read(config_path)).result) }
+
+  context "when incoming email is disabled" do
+    before do
+      ENV["MAIL_ROOM_GITLAB_CONFIG_FILE"] = Rails.root.join("spec/fixtures/mail_room_disabled.yml").to_s
+    end
+
+    after do
+      ENV["MAIL_ROOM_GITLAB_CONFIG_FILE"] = nil
+    end
+
+    it "contains no configuration" do
+      expect(configuration[:mailboxes]).to be_nil
+    end
+  end
+
+  context "when incoming email is enabled" do
+    before do
+      ENV["MAIL_ROOM_GITLAB_CONFIG_FILE"] = Rails.root.join("spec/fixtures/mail_room_enabled.yml").to_s
+    end
+
+    after do
+      ENV["MAIL_ROOM_GITLAB_CONFIG_FILE"] = nil
+    end
+
+    it "contains the intended configuration" do
+      expect(configuration[:mailboxes].length).to eq(1)
+
+      mailbox = configuration[:mailboxes].first
+
+      expect(mailbox[:host]).to eq("imap.gmail.com")
+      expect(mailbox[:port]).to eq(993)
+      expect(mailbox[:ssl]).to eq(true)
+      expect(mailbox[:start_tls]).to eq(false)
+      expect(mailbox[:email]).to eq("gitlab-incoming@gmail.com")
+      expect(mailbox[:password]).to eq("[REDACTED]")
+      expect(mailbox[:name]).to eq("inbox")
+
+      redis_config_file = Rails.root.join('config', 'resque.yml')
+
+      redis_url =
+        if File.exists?(redis_config_file)
+          YAML.load_file(redis_config_file)[Rails.env]
+        else
+          "redis://localhost:6379"
+        end
+
+      expect(mailbox[:delivery_options][:redis_url]).to eq(redis_url)
+      expect(mailbox[:arbitration_options][:redis_url]).to eq(redis_url)
+    end
+  end
+end

spec/fixtures/mail_room_disabled.yml

+test:
+  incoming_email:
+    enabled: false
+    address: "gitlab-incoming+%{key}@gmail.com"
+    user: "gitlab-incoming@gmail.com"
+    password: "[REDACTED]"
+    host: "imap.gmail.com"
+    port: 993
+    ssl: true
+    start_tls: false
+    mailbox: "inbox"

spec/fixtures/mail_room_enabled.yml

+test:
+  incoming_email:
+    enabled: true
+    address: "gitlab-incoming+%{key}@gmail.com"
+    user: "gitlab-incoming@gmail.com"
+    password: "[REDACTED]"
+    host: "imap.gmail.com"
+    port: 993
+    ssl: true
+    start_tls: false
+    mailbox: "inbox"