Parameters: Bucket: Type: String CodeKey: Type: String SwaggerKey: Type: String AliasName: Type: String Default: Live Globals: Function: AutoPublishAlias: Ref: AliasName Resources: MyLambdaFunction: Type: AWS::Serverless::Function Properties: Handler: index.handler Runtime: nodejs14.x CodeUri: # Just trying to create a complex intrinsic function where only a part of it can be resolved Bucket: Fn::Join: ['', [Ref: Bucket]] Key: # Even though the entire Sub won't be resolved, translator will substitute ${Key} with value passed at runtime Fn::Sub: ${CodeKey} Metadata: SamTransformTest: true