AWS CloudFormation Concepts Condition Functions: Difference between revisions
Jump to navigation
Jump to search
| (One intermediate revision by the same user not shown) | |||
| Line 27: | Line 27: | ||
=Fn::Not: !Not= | =Fn::Not: !Not= | ||
For YAML syntax reasons, it's best to leave spaces around [ and ]. | |||
Conditions: | Conditions: | ||
SomeCondition: | |||
Fn::Not: [!Equals ['blue', !Ref SomeParameter]] | Fn::Not: [ !Equals [ 'blue', !Ref SomeParameter ] ] | ||
Conditions: | |||
SomeCondition: | |||
!Not [ !Equals [ 'blue', !Ref SomeParameter ] ] | |||
=Fn::Or: !Or= | =Fn::Or: !Or= | ||
Latest revision as of 19:12, 18 April 2019
External
Internal
Overview
As it is the case for intrinsic functions, condition functions have a full function name, and a short form. For more details see:
Fn::If: !If
Fn::If: function can be used to conditionally specify a property.
Fn::If is only supported in the metadata attribute, update policy attribute, and property values in the Resources section and Outputs sections of a template.
Fn::And: !And
Fn::Equals: !Equals
!Equals ['something', !Ref SomethingElse]
Fn::Not: !Not
For YAML syntax reasons, it's best to leave spaces around [ and ].
Conditions:
SomeCondition:
Fn::Not: [ !Equals [ 'blue', !Ref SomeParameter ] ]
Conditions: SomeCondition: !Not [ !Equals [ 'blue', !Ref SomeParameter ] ]
Fn::Or: !Or
Expressions
Expressions can use pseudo-parameters, template input parameters and mappings. Expressions are useful when declaring Conditions. Other conditions can be referenced within conditions.