[Bug]: Can't apply aws_globalaccelerator_endpoint_group resource after modifying the weight

[taisytran]

Terraform Core Version

1.3.7

AWS Provider Version

4.56.0

Affected Resource(s)

aws_globalaccelerator_endpoint_group

Expected Behavior

The weight's value can be applied after modifying

Actual Behavior

The weight's value couldn't be applied after modifying

Relevant Error/Panic Output Snippet

No response

Terraform Configuration Files

...

Steps to Reproduce

1. Create a aws_globalaccelerator_endpoint_group resource.
2. Add 2 endpoint_configuration blocks
3. Set weight the first block is 0 and the second block is 100
4. Run TF plan and hit TF Apply the plan (1st time)
5. After applying, modify the first block is 100 and the second is 0
6. Run TF plan and hit TF Apply again (2nd time)
7. After applying, Run TF plan again (3rd time), the changes of aws_globalaccelerator_endpoint_group still be there (couldn't be applied)

Debug Output

No response

Panic Output

No response

Important Factoids

No response

References

No response

Would you like to implement a fix?

None

[github-actions]

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[justinretzolk]

Hey @taisytran 👋 Thank you for taking the time to raise this! So that we have the necessary information in order to look into this, can you supply a sample Terraform configuration as well as debug logs (redacted as needed)?

[taisytran]

Hey @taisytran 👋 Thank you for taking the time to raise this! So that we have the necessary information in order to look into this, can you supply a sample Terraform configuration as well as debug logs (redacted as needed)?

Thank you for your support. Here is my TF configuration

terraform {
  required_version = ">= 0.13"
  required_providers {
    aws = {
      source = "hashicorp/aws"
      version = "~> 4.56.0"
    }
  }
}

provider "aws" {
  region = "us-east-1"
}

resource "aws_globalaccelerator_accelerator" "ga" {
  name            = "my-ga"
  ip_address_type = "IPV4"
  enabled         = true

  attributes {...}
}

resource "aws_globalaccelerator_listener" "ga_listenner" {
  accelerator_arn = aws_globalaccelerator_accelerator.ga.id
  client_affinity = "NONE"
  protocol        = "TCP"

  port_range {
    from_port = 443
    to_port   = 443
  }
  port_range {
    from_port = 80
    to_port   = 80
  }
}

resource "aws_lb" "old_alb" {...}
resource "aws_lb" "new_alb" {...}

resource "aws_globalaccelerator_endpoint_group" "ga_endpoint" {
  listener_arn      = aws_globalaccelerator_listener.ga_listenner.id
  health_check_port = "443"

  endpoint_configuration {
    client_ip_preservation_enabled = true
    endpoint_id = aws_lb.old_alb.arn
    weight      = "0"
  }

  endpoint_configuration {
    client_ip_preservation_enabled = true
    endpoint_id = aws_lb.new_alb.arn
    weight      = "100"
  }
}

[gagan-eg]

We are having possibly a similar issue. It seems that if the weight for an endpoint is set to 0 it is dropped API call to aws. I checked the Cloud Trail and with a weight of 0 in an endpoint configuration, I keep seeing

        "endpointConfigurations": [
            {
                "endpointId": "some_arn",
                "clientIPPreservationEnabled": false
>>>>>> (No weight field which in TF state file is 0. This causes weight to get set to 128 instead of 0.
            },
            {
                "endpointId": "some other arn",
                "weight": 100,
                "clientIPPreservationEnabled": false
            }
        ],

[gagan-eg]

Just as an update, It seems when this happens when you add a new endpoint in an endpoint group with its weight set to 0.

[yannrouillard]

I confirm this bug, a weight of 0 is ignored, it seems to be caused by this line:

terraform-provider-aws/internal/service/globalaccelerator/endpoint_group.go

Line 380 in 1f7066c

if v, ok := tfMap["weight"].(int); ok && v != 0 {

As a result, as no weight is sent in the API call, the value of 128 is used by AWS instead of 0 when creating a new endpoint configuration (which is kind of unexpected)

[github-actions]

This functionality has been released in v5.2.0 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. Thank you!

[github-actions]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.
If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.