Giving OriginAccessIdentity reference in CloudFormation or serverless.yml

Question

I want to have a CloudFront distribution with access to a private S3 bucket. For that, I have to create an origin access identity. Manually, I can do that using the AWS console, but I wanted to create it via a CloudFormation script or with Serverless (using serverless.yml). While doing this, I am able to add a physical Id of the origin access identity to my CloudFront distribution (using one script).

Relevant documentation: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/quickref-cloudfront.html

I tried this:

myDistribution:
  Type: AWS::CloudFront::Distribution
  Properties:
    DistributionConfig:
      Origins:
      - DomainName:bucket.s3.amazonaws.com
        Id: myS3Origin
        S3OriginConfig: {
          OriginAccessIdentity:origin-access-identity/cloudfront/ !Ref cloudfrontoriginaccessidentity
        }
      Enabled: 'true'
      Comment: Some comment
      DefaultCacheBehavior:
        ForwardedValues:
          QueryString: 'false'
          Cookies:
            Forward: none
        AllowedMethods:
        - GET
        - HEAD
        - OPTIONS
        TargetOriginId: myS3Origin
        ViewerProtocolPolicy: redirect-to-https
      PriceClass: PriceClass_200
      ViewerCertificate:
        CloudFrontDefaultCertificate: 'true'
cloudfrontoriginaccessidentity:
  Type: AWS::CloudFront::CloudFrontOriginAccessIdentity
  Properties:
    CloudFrontOriginAccessIdentityConfig:
      Comment: "some comment"

I have to create an origin access identity and a CloudFront distribution having this identity. Can we do both of these things in one CloudFormation script or with Serverless (using serverless.yml)?

Answer 1

You definitely can create an origin access identity and the CloudFront distribution in the same serverless.yml.

I've modified your scenario and changed the OriginAccessIdentity to use Fn::Join.

myDistribution:
  Type: AWS::CloudFront::Distribution
  Properties:
    DistributionConfig:
      Origins:
      - DomainName:bucket.s3.amazonaws.com
        Id: myS3Origin
        S3OriginConfig:
          OriginAccessIdentity:
            Fn::Join:
              - ''
              -
                - 'origin-access-identity/cloudfront/'
                - Ref: cloudfrontoriginaccessidentity
      Enabled: 'true'
      Comment: Some comment
      DefaultCacheBehavior:
        ForwardedValues:
          QueryString: 'false'
          Cookies:
            Forward: none
        AllowedMethods:
        - GET
        - HEAD
        - OPTIONS
        TargetOriginId: myS3Origin
        ViewerProtocolPolicy: redirect-to-https
      PriceClass: PriceClass_200
      ViewerCertificate:
        CloudFrontDefaultCertificate: 'true'

cloudfrontoriginaccessidentity:
  Type: AWS::CloudFront::CloudFrontOriginAccessIdentity
  Properties:
    CloudFrontOriginAccessIdentityConfig:
      Comment: "some comment"

The serverless examples repo has a great example of this too: https://github.com/serverless/examples/blob/master/aws-node-single-page-app-via-cloudfront/serverless.yml