1 files changed, 33 insertions, 0 deletions
diff --git a/lib/gitlab/ci/config/interpolation/functions/expand_vars.rb b/lib/gitlab/ci/config/interpolation/functions/expand_vars.rb
new file mode 100644
index 00000000000..658964018b5
--- /dev/null
+++ b/lib/gitlab/ci/config/interpolation/functions/expand_vars.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    class Config
+      module Interpolation
+        module Functions
+          class ExpandVars < Base
+            def self.function_expression_pattern
+              /^#{name}$/
+            end
+
+            def self.name
+              'expand_vars'
+            end
+
+            def execute(input_value)
+              unless input_value.is_a?(String)
+                error("invalid input type: #{self.class.name} can only be used with string inputs")
+                return
+              end
+
+              ExpandVariables.expand_existing(input_value, ctx.variables, fail_on_masked: true)
+            rescue ExpandVariables::VariableExpansionError => e
+              error("variable expansion error: #{e.message}")
+              nil
+            end
+          end
+        end
+      end
+    end
+  end
+end