Feature Request: CloudFront Functions

[alexjurkiewicz]

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Description

Please add support for CloudFront Functions

New or Affected Resource(s)

• aws_cloudfront_function

Potential Terraform Configuration

resource "aws_cloudfront_function" "default" {
  name = "test"
  runtime = "cloudfront-js-1.0"
  comment = "my function"
  publish = true
  code = file("${path.module}/function.js")
}

References

• Launch blog: https://blog.github.com/2016-03-10-add-reactions-to-pull-requests-issues-and-comments/
• Developer docs: https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/cloudfront-functions.html
• API docs: https://docs.aws.amazon.com/cloudfront/latest/APIReference/API_CreateFunction.html

[ewbankkit]

Requires AWS SDK v1.38.30:

• build(deps): bump github.com/aws/aws-sdk-go from 1.38.29 to 1.38.31 #19224

[chrs-myrs]

We have been working with AWS on the private preview here, the above functionality creates the function, but what we urgently need is the ability to assign a function to a CloudFront Behaviour. We wouldn't use the above suggestion as our functions are deployed and published by a deployment pipeline. Currently we need to do the Function -> Behaviour assignment manually, but this is the perfect job for Terraform (which currently unassociates the functions every time an apply is made affecting a distribution)

[dbednall]

Cloudfront Functions basically get associated to distribution behaviour(s) like Lambda@Edge

In addition to the proposed new resource is a change is required to cloudfront_distribution to have a new config block to manage the function association as part of a Default/Ordered Cache Behaviour configuration.

So taking inspiration from the existing config block for Lambda@Edge: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/cloudfront_distribution#lambda-function-association this feature requires the following

ordered_cache_behavior {
    # ... other configuration ...

    # zero or more of 
    function_association {
      event_type   = "viewer-request"
      # the specific event to trigger this function. Valid values: viewer-request, viewer-response

      arn   = aws_cloudfront_function.default.arn
      #  e.g. arn:aws:cloudfront::000000000001:function/test
    }
  }

Some might say function_association {} should be cloudfront_function_association {} or similar to fully distinguish from lambda_function_association {} but the API doesn't https://docs.aws.amazon.com/cloudfront/latest/APIReference/API_DefaultCacheBehavior.html (see FunctionAssociations)

---

Alternatively the config block could be made generic to handle both the association of Lambda@Edge functions AND Cloudfront Functions fuctions and deprecate lambda_function_association {}

[ZsoltPath]

Is someone working on this? I could give it a go next week.

[rgant]

Is there any work around in the meantime that I can use to stop terraform from removing the cloudfront functions from my distributions?

Right now every time my cloudfront distribution is modified it removes the functions without warning me. Even something that warns me would be good.

[andy-b-84]

Is there any work around in the meantime that I can use to stop terraform from removing the cloudfront functions from my distributions?

Right now every time my cloudfront distribution is modified it removes the functions without warning me. Even something that warns me would be good.

The best you can get, without using a branch or a fork for the provider, would be to execute terraform plan & terraform apply using -target options and not target your aws_cloudfront_distributions .

[ghost]

This has been released in version 3.41.0 of the Terraform AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template for triage. Thanks!

[github-actions]

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