1 files changed, 52 insertions, 0 deletions
diff --git a/lib/gitlab/ci/project_config.rb b/lib/gitlab/ci/project_config.rb
new file mode 100644
index 00000000000..ded6877ef29
--- /dev/null
+++ b/lib/gitlab/ci/project_config.rb
@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    # Locates project CI config
+    class ProjectConfig
+      # The order of sources is important:
+      # - EE uses Compliance first since it must be used first if compliance templates are enabled.
+      #   (see ee/lib/ee/gitlab/ci/project_config.rb)
+      # - Parameter is used by on-demand security scanning which passes the actual CI YAML to use as argument.
+      # - Bridge is used for downstream pipelines since the config is defined in the bridge job. If lower in priority,
+      #   it would evaluate the project's YAML file instead.
+      # - Repository / ExternalProject / Remote: their order is not important between each other.
+      # - AutoDevops is used as default option if nothing else is found and if AutoDevops is enabled.
+      SOURCES = [
+        ProjectConfig::Parameter,
+        ProjectConfig::Bridge,
+        ProjectConfig::Repository,
+        ProjectConfig::ExternalProject,
+        ProjectConfig::Remote,
+        ProjectConfig::AutoDevops
+      ].freeze
+
+      def initialize(project:, sha:, custom_content: nil, pipeline_source: nil, pipeline_source_bridge: nil)
+        @config = find_config(project, sha, custom_content, pipeline_source, pipeline_source_bridge)
+      end
+
+      delegate :content, :source, to: :@config, allow_nil: true
+
+      def exists?
+        !!@config&.exists?
+      end
+
+      private
+
+      def find_config(project, sha, custom_content, pipeline_source, pipeline_source_bridge)
+        sources.each do |source|
+          config = source.new(project, sha, custom_content, pipeline_source, pipeline_source_bridge)
+          return config if config.exists?
+        end
+
+        nil
+      end
+
+      def sources
+        SOURCES
+      end
+    end
+  end
+end
+
+Gitlab::Ci::ProjectConfig.prepend_mod_with('Gitlab::Ci::ProjectConfig')