Creation of "aws_appmesh_route" fails if one of the "weighted_targets" has "weight = 0"

[mkielar]

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Terraform Version

0.12.20

Affected Resource(s)

• aws_appmesh_route

Terraform Configuration Files

resource "aws_appmesh_route" "vrr" {
  mesh_name           = var.appmesh.name
  name                = local.name
  virtual_router_name = aws_appmesh_virtual_router.vr.name

  spec {
    http_route {
      match {
        prefix = "/"
      }

      action {
        dynamic "weighted_target" {
          for_each = local.deployments
          content {
            virtual_node = aws_appmesh_virtual_node.vn[weighted_target.key].name
            weight       = weighted_target.value.weight
          }
        }
      }
    }
  }

}

Terraform Plan Output

 Terraform will perform the following actions:
   # module.[MASKED].module.[MASKED].aws_appmesh_route.vrr will be updated in-place
   ~ resource "aws_appmesh_route" "vrr" {
         arn                 = "arn:aws:appmesh:eu-west-1:[MASKED]:mesh/[MASKED]/virtualRouter/[MASKED]/route/[MASKED]"
         created_date        = "2020-05-23T22:46:26Z"
         id                  = "[MASKED]"
         last_updated_date   = "2020-05-23T22:46:26Z"
         mesh_name           = "[MASKED]"
         name                = "[MASKED]"
         tags                = {}
         virtual_router_name = "[MASKED]"
       ~ spec {
             priority = 0
           ~ http_route {
               ~ action {
                   + weighted_target {
                       + virtual_node = "[MASKED]-blue"
                       + weight       = 100
                     }
                   - weighted_target {
                       - virtual_node = "[MASKED]-blue" -> null
                       - weight       = 90 -> null
                     }
                   + weighted_target {
                       + virtual_node = "[MASKED]-green"
                       + weight       = 0
                     }
                   - weighted_target {
                       - virtual_node = "[MASKED]-green" -> null
                       - weight       = 10 -> null
                     }
                 }
                 match {
                     prefix = "/"
                 }
             }
         }
     }

Debug Output

�[0m�[1mmodule.[MASKED].module.[MASKED].aws_appmesh_route.vrr: Modifying... [id=c662fd86-1630-492c-952e-2cca14d07795]�[0m�[0m
2020/05/25 00:01:01 [DEBUG] module.[MASKED].module.[MASKED].aws_appmesh_route.vrr: applying the planned Update change
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4: 2020/05/25 00:01:01 [DEBUG] Updating App Mesh route: {
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:   MeshName: "[MASKED]",
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:   RouteName: "[MASKED]",
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:   Spec: {
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:     HttpRoute: {
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:       Action: {
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:         WeightedTargets: [{
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:             VirtualNode: "[MASKED]"
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:           },{
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:             VirtualNode: "[MASKED]",
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:             Weight: 100
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:           }]
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:       },
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:       Match: {
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:         Prefix: "/"
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:       }
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:     }
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:   },
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4:   VirtualRouterName: "[MASKED]"
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4: }
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4: 2020/05/25 00:01:01 [DEBUG] [aws-sdk-go] DEBUG: Validate Request App Mesh/UpdateRoute failed, not retrying, error InvalidParameter: 1 validation error(s) found.
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4: - missing required field, UpdateRouteInput.Spec.HttpRoute.Action.WeightedTargets[0].Weight.
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4: 2020/05/25 00:01:01 [DEBUG] [aws-sdk-go] DEBUG: Build Request App Mesh/UpdateRoute failed, not retrying, error InvalidParameter: 1 validation error(s) found.
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4: - missing required field, UpdateRouteInput.Spec.HttpRoute.Action.WeightedTargets[0].Weight.
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4: 2020/05/25 00:01:01 [DEBUG] [aws-sdk-go] DEBUG: Sign Request App Mesh/UpdateRoute failed, not retrying, error InvalidParameter: 1 validation error(s) found.
2020-05-25T00:01:01.973Z [DEBUG] plugin.terraform-provider-aws_v2.63.0_x4: - missing required field, UpdateRouteInput.Spec.HttpRoute.Action.WeightedTargets[0].Weight.
2020/05/25 00:01:01 [DEBUG] module.[MASKED].module.[MASKED].aws_appmesh_route.vrr: apply errored, but we're indicating that via the Error pointer rather than returning it: error updating App Mesh route: InvalidParameter: 1 validation error(s) found.
- missing required field, UpdateRouteInput.Spec.HttpRoute.Action.WeightedTargets[0].Weight.
2020/05/25 00:01:01 [ERROR] module.[MASKED].module.[MASKED]: eval: *terraform.EvalApplyPost, err: error updating App Mesh route: InvalidParameter: 1 validation error(s) found.
- missing required field, UpdateRouteInput.Spec.HttpRoute.Action.WeightedTargets[0].Weight.
2020/05/25 00:01:01 [ERROR] module.[MASKED].module.[MASKED]: eval: *terraform.EvalSequence, err: error updating App Mesh route: InvalidParameter: 1 validation error(s) found.
- missing required field, UpdateRouteInput.Spec.HttpRoute.Action.WeightedTargets[0].Weight.

Panic Output

N/A

Expected Behavior

I'm deploying a new version of service and want the old one to have 100% traffic routed on Virtual Router, while the new one initially gets no traffic. I intend script traffic shifting for Canary Deployments and make it happen outside of terraform.

I checked that this configuration is possible, by manually created two routes (one with 100% weight, and the other with 0% weight) in AWS Console.

The output of terraform plan properly shows that it will set one of the weights to 100 and the other to 0.

The expected behaviour in this case is that the resource gets updated accordingly.

Actual Behavior

The API Call (see the debug log) shows, that - were weight was intended to be 0 - the attribute is not sent to AWS at all. Instead Terraform attempts to send malformed message, lacking weight attribute in one of the WeightedTargets, and AWS Rejects that request with an error message:

 Error: error updating App Mesh route: InvalidParameter: 1 validation error(s) found.
 - missing required field, UpdateRouteInput.Spec.HttpRoute.Action.WeightedTargets[0].Weight.
   on .terraform/modules/[MASKED].[MASKED]/terraform/modules/ecs/service_blue_green/appmesh.tf line 67, in resource "aws_appmesh_route" "vrr":
   67: resource "aws_appmesh_route" "vrr" {

Steps to Reproduce

1. Create a deployment of aws_appmesh_route with one of the weighted_target.weight set to 0.
2. terraform apply

Important Factoids

References

[ewbankkit]

Will need to change

https://github.com/terraform-providers/terraform-provider-aws/blob/2cc9c47a4f152c250609a88351dd72da3c2368e8/aws/structure.go#L5133-L5135

and

https://github.com/terraform-providers/terraform-provider-aws/blob/2cc9c47a4f152c250609a88351dd72da3c2368e8/aws/structure.go#L5237-L5239

[anGie44]

The fix for this has been merged and will release with version 2.65.0 of the Terraform AWS Provider, expected in this week's release.

[ghost]

This has been released in version 2.65.0 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!

[ghost]

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 feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!