Add support for `extends` key in CI/CD configuration

3 files changed, 20 insertions, 7 deletions

diff --git a/lib/gitlab/ci/config.rb b/lib/gitlab/ci/config.rb
index 66ac4a40616..2a53d43e761 100644
--- a/lib/gitlab/ci/config.rb
+++ b/lib/gitlab/ci/config.rb
@@ -4,12 +4,17 @@ module Gitlab
     # Base GitLab CI Configuration facade
     #
     class Config
-      # EE would override this and utilize opts argument
+      ConfigError = Class.new(StandardError)
+
       def initialize(config, opts = {})
-        @config = Loader.new(config).load!
+        @config = Extendable::Collection
+          .new(build_config(config, opts))
+          .to_hash
 
         @global = Entry::Global.new(@config)
         @global.compose!
+      rescue Loader::FormatError, Extendable::Collection::ExtensionError => e
+        raise Config::ConfigError, e.message
       end
 
       def valid?
@@ -58,6 +63,11 @@ module Gitlab
       def jobs
         @global.jobs_value
       end
+
+      # 'opts' argument is used in EE see /ee/lib/ee/gitlab/ci/config.rb
+      def build_config(config, opts = {})
+        Loader.new(config).load!
+      end
     end
   end
 end
diff --git a/lib/gitlab/ci/config/entry/job.rb b/lib/gitlab/ci/config/entry/job.rb
index 91aac6df4b1..016a896bde5 100644
--- a/lib/gitlab/ci/config/entry/job.rb
+++ b/lib/gitlab/ci/config/entry/job.rb
@@ -9,9 +9,10 @@ module Gitlab
           include Configurable
           include Attributable
 
-          ALLOWED_KEYS = %i[tags script only except type image services allow_failure
-                            type stage when artifacts cache dependencies before_script
-                            after_script variables environment coverage retry].freeze
+          ALLOWED_KEYS = %i[tags script only except type image services
+                            allow_failure type stage when artifacts cache
+                            dependencies before_script after_script variables
+                            environment coverage retry extends].freeze
 
           validations do
             validates :config, allowed_keys: ALLOWED_KEYS
@@ -32,6 +33,7 @@ module Gitlab
                                       'always or manual' }
 
               validates :dependencies, array_of_strings: true
+              validates :extends, type: String
             end
           end
 
@@ -81,7 +83,8 @@ module Gitlab
                   :cache, :image, :services, :only, :except, :variables,
                   :artifacts, :commands, :environment, :coverage, :retry
 
-          attributes :script, :tags, :allow_failure, :when, :dependencies, :retry
+          attributes :script, :tags, :allow_failure, :when, :dependencies,
+                     :retry, :extends
 
           def compose!(deps = nil)
             super do
diff --git a/lib/gitlab/ci/yaml_processor.rb b/lib/gitlab/ci/yaml_processor.rb
index e829f2a95f8..5d1864ae9e2 100644
--- a/lib/gitlab/ci/yaml_processor.rb
+++ b/lib/gitlab/ci/yaml_processor.rb
@@ -16,7 +16,7 @@ module Gitlab
         end
 
         initial_parsing
-      rescue Gitlab::Ci::Config::Loader::FormatError => e
+      rescue Gitlab::Ci::Config::ConfigError => e
         raise ValidationError, e.message
       end