AWS CloudFormation Concepts Intrinsic Functions: Difference between revisions

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{{External|[https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-sub.html Sub]}}
{{External|[https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-sub.html Sub]}}
If only template parameters, resource logical IDs and resource attributes are substituted in the String parameter, no variable map is required:
!Sub '${AWS::Region}-something'

Revision as of 19:33, 13 March 2019

External

Intrinsic Function Reference

Internal

Ref

Ref

The intrinsic function Ref returns the value of the specified parameter or resource. When a parameter logical name is specified, it returns the value of the parameter. When a resource logical name is specified, it returns a value that can be typically used to refer to that resource, such as a physical ID.

Join

Join
!Join [ delimiter, [ comma-delimited list of values ] ]
!Join ['-', [ a, b, c ]]

returns "a:b:c"

Split

Split
!Split ['.', "www.example.com"]

returns ["www", "example", "com"].

Select

Select

Sub

Sub

If only template parameters, resource logical IDs and resource attributes are substituted in the String parameter, no variable map is required:

!Sub '${AWS::Region}-something'