04 Apr 2019

Conditionally create CodePipeline Actions based on Cloudformation Conditions

You can accomplish this by conditionally by inserting the AWS::CodePipeline::Pipeline Resource’s Action into the Actions list using the Fn::If Intrinsic Function referencing your Conditions element, returning the Action when the Condition is true and AWS::NoValue (which removes the property, in this case removing the item from the list) when it is not true.

For example we can cause particular element to be included when the stack is created based on a parameter.

In this case, lets look at deploying a redis cluster Cloudformation file when the pipeline is ran.

We add the parameter and give it some allowed values.

    Type: String
    Description: Do you want to create a redis? (yes/no)
    Default: "no"
    AllowedValues: ["yes", "no"]

Then setup a conditional based on it:

  NeedsRedis: !Equals [ !Ref CreateRedis, "yes" ]

Then in the Actions Section of the CodePipeline resource we can toggle a sections inclusion based on the state of the condition:

- !If 
- NeedsRedis
- Name: !Sub "${ApplicationName}-redis"
  RunOrder: 2
    - Name: Build
    Category: Deploy
    Owner: AWS
    Version: '1'
    Provider: CloudFormation
    RoleArn: !Sub "${CodePipelineCloudFormationRole.Arn}"
    Capabilities: CAPABILITY_NAMED_IAM
    StackName: !Sub "${ApplicationName}-redis"
    TemplatePath: Build::cloudformation/redis.cform
    ParameterOverrides: !Sub |
        "ApplicationName": "${ApplicationName}"
- !Ref AWS::NoValue