deepmerge: - name: deepMerge template: Fn::DeepMerge: - us-east-1: object: one: - "a" - "b" - "c" two: two account1: - "1" - "2" - "3" - us-east-1: object: one: - "d" - "e" - "f" three: three four: four account1: - "4" - "5" - "6" output: us-east-1: object: one: - "a" - "b" - "c" - "d" - "e" - "f" two: two three: three four: four account1: - "1" - "2" - "3" - "4" - "5" - "6" - name: deepMerge With Include template: Grabbed: Fn::Include: "./fixtures/foobar.json" Fn::DeepMerge: - us-east-1: object: one: - "a" - "b" - "c" two: two account1: - "1" - "2" - "3" - us-east-1: object: one: - "d" - "e" - "f" three: three four: four account1: - "4" - "5" - "6" output: Grabbed: foo: bar us-east-1: object: one: - "a" - "b" - "c" - "d" - "e" - "f" two: two three: three four: four account1: - "1" - "2" - "3" - "4" - "5" - "6"