[Bug]: Wrong ARN for AWS Amplify Webhooks

[AriannaLanz]

Terraform Core Version

1.9.0

AWS Provider Version

5.67.0

Affected Resource(s)

aws_amplify_webhook

Expected Behavior

The output of aws_amplify_webhook.example_webhook.arn should be arn:aws:amplify:<region>:<account-id>:webhooks/<webhook-id>.

Actual Behavior

The actual output of aws_amplify_webhook.example_webhook.arn is arn:aws:amplify:<region>:<account-id>:apps/<app-id>/webhooks/<webhook-id>

Relevant Error/Panic Output Snippet

No response

Terraform Configuration Files

terraform {
required_providers {
aws = {
source = "hashicorp/aws"
version = "> 5.0"
}
}
required_version = "> 1.9.0"
}

Steps to Reproduce

resource "aws_amplify_app" "example" {
  name = "app"
}

resource "aws_amplify_branch" "master" {
  app_id      = aws_amplify_app.example.id
  branch_name = "master"
}

resource "aws_amplify_webhook" "master" {
  app_id      = aws_amplify_app.example.id
  branch_name = aws_amplify_branch.master.branch_name
  description = "triggermaster"
}

2. terraform apply
3. terraform state show aws_amplify_webhook.master

Debug Output

No response

Panic Output

No response

Important Factoids

I need to add an amplify:GetWebhook IAM permission for this specific webhook, but I was getting the error:

Error: reading Amplify Webhook (<webhook-id>): operation error Amplify: GetWebhook, https response error StatusCode: 403, RequestID: <request-id id>, api error AccessDeniedException: User: arn:aws:sts::<account-id>:assumed-role/<role> is not authorized to perform: amplify:GetWebhook on resource: arn:aws:amplify:<region>:<account-id>:webhooks/<webhook-id>

and I noticed the discrepancy in that Terraform outputs the ARN as arn:aws:amplify:<region>:<account-id>:apps/<app-id>/webhooks/<webhook-id> when AWS expects arn:aws:amplify:<region>:<account-id>:webhooks/<webhook-id> (without the apps/<app-id> part).

When I fixed this manually in the IAM console, I no longer saw the 403 error.

References

No response

Would you like to implement a fix?

None

[github-actions]

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[RomanGonzalezEA]

This issue has now become critical as it's actively blocking the creation of an Amplify webhook with the error:
Error: unexpected format for ARN resource (webhooks/webhook_id)

The root cause appears to stem from the ARN format discrepancy described earlier. Terraform's generated ARN (...:apps/<app-id>/webhooks/<webhook-id>) conflicts with AWS's expected format (...:webhooks/<webhook-id>), which is now causing resource creation failures in addition to the original IAM permission issues.

Additionally, I confirm that I am using version 5.86.0 of the AWS Terraform provider.

[brunokloss]

+1. It isn't working here as well.
Terraform creates the webhook, but then shows the message Error: unexpected format for ARN resource (webhooks/webhook_id)

[Yuan-Verity]

Probably AWS changed the webhook URL structure yesterday. Now all projects with amplify webhook are failing.

[brunordias]

+1
Error: unexpected format for ARN resource (webhooks/<id>)
My plan failed with this error. I deleted the webhook to proceed, then re-ran the plan, and it successfully recreated the webhook. However, I still got the same error at the end of the apply.

[mhd-rawashdah]

We are experiencing the same issue where all our pipelines have failed any suggested solution?

[carvantes]

Hi, I'm from AWS Amplify.

There was a change in the ARN format on the API responses for webhooks. The change has been reverted.

You should not experience the Error: unexpected format for ARN resource (webhooks/webhook_id) anymore. We apologize for the inconvenience