1 files changed, 26 insertions, 0 deletions
diff --git a/lib/gitlab/ci/config/dependencies.rb b/lib/gitlab/ci/config/dependencies.rb
new file mode 100644
index 00000000000..9029e5f5155
--- /dev/null
+++ b/lib/gitlab/ci/config/dependencies.rb
@@ -0,0 +1,26 @@
+module Gitlab
+  module Ci
+    class Config
+      class Dependencies
+        class UnmetDependencyError < StandardError; end
+
+        def initialize
+          @entries = {}
+        end
+
+        def visit(entry)
+          @entries[entry.location] = entry
+          entry.dependencies = self
+        end
+
+        def entry(location)
+          unless @entries.has_key?(location)
+            raise UnmetDependencyError, "Unmet dependency #{location}"
+          end
+
+          @entries[location]
+        end
+      end
+    end
+  end
+end