Diffs didn't match - AWS ASG

[hashibot]

This issue was originally opened by @GlowUpATeam as hashicorp/terraform#17092. It was migrated here as a result of the provider split. The original body of the issue is below.

---

Terraform Version

0.11.1
...

### Terraform Configuration Files
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```hcl
...
`resource "random_id" "asg" {
 byte_length = 8
}


resource "aws_autoscaling_group" "asg" {
  availability_zones = ["${var.aws_region}a", "${var.aws_region}c"]
  name = "asg-${aws_launch_configuration.devopslc.id}"
  max_size = "${var.asg_max}"
  min_size = "${var.asg_min}"
  health_check_grace_period = "${var.asg_grace}"
  health_check_type = "${var.asg_hct}"
  desired_capacity = "${var.asg_cap}"
  force_delete = true
  load_balancers = ["${aws_alb.devops_alb.id}"]
  vpc_zone_identifier = ["${aws_subnet.devops_private.*.id}"]
  launch_configuration = "${aws_launch_configuration.devopslc.name}"

  tag {
    key = "Name"
    value = "asg-instance"
    propagate_at_launch = true
    }

  lifecycle {
    create_before_destroy = true
  }
}
`

### Debug Output
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### Crash Output
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Mismatch reason: attribute mismatch: availability_zones.3569565595
    Diff One (usually from plan): *terraform.InstanceDiff{mu:sync.Mutex{state:0, sema:0x0}, Attributes:map[string]*terraform.ResourceAttrDiff{"default_cooldown":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "max_size":*terraform.ResourceAttrDiff{Old:"", New:"4", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "launch_configuration":*terraform.ResourceAttrDiff{Old:"", New:"${aws_launch_configuration.devopslc.name}", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "availability_zones.#":*terraform.ResourceAttrDiff{Old:"", New:"2", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "protect_from_scale_in":*terraform.ResourceAttrDiff{Old:"", New:"false", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "tag.#":*terraform.ResourceAttrDiff{Old:"", New:"1", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "tag.18571221.key":*terraform.ResourceAttrDiff{Old:"", New:"Name", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "health_check_type":*terraform.ResourceAttrDiff{Old:"", New:"EC2", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "availability_zones.986537655":*terraform.ResourceAttrDiff{Old:"", New:"us-east-1c", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "tag.18571221.value":*terraform.ResourceAttrDiff{Old:"", New:"asg-instance", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "vpc_zone_identifier.#":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "availability_zones.3569565595":*terraform.ResourceAttrDiff{Old:"", New:"us-east-1a", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "wait_for_capacity_timeout":*terraform.ResourceAttrDiff{Old:"", New:"10m", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "desired_capacity":*terraform.ResourceAttrDiff{Old:"", New:"4", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "metrics_granularity":*terraform.ResourceAttrDiff{Old:"", New:"1Minute", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "tag.18571221.propagate_at_launch":*terraform.ResourceAttrDiff{Old:"", New:"true", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "load_balancers.#":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "min_size":*terraform.ResourceAttrDiff{Old:"", New:"2", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "target_group_arns.#":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "force_delete":*terraform.ResourceAttrDiff{Old:"", New:"true", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "arn":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "health_check_grace_period":*terraform.ResourceAttrDiff{Old:"", New:"300", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "name":*terraform.ResourceAttrDiff{Old:"", New:"asg-${aws_launch_configuration.devopslc.id}", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}}, Destroy:false, DestroyDeposed:false, DestroyTainted:false, Meta:map[string]interface {}(nil)}
    Diff Two (usually from apply): *terraform.InstanceDiff{mu:sync.Mutex{state:0, sema:0x0}, Attributes:map[string]*terraform.ResourceAttrDiff{"tag.18571221.key":*terraform.ResourceAttrDiff{Old:"", New:"Name", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "health_check_type":*terraform.ResourceAttrDiff{Old:"", New:"EC2", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "wait_for_capacity_timeout":*terraform.ResourceAttrDiff{Old:"", New:"10m", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "metrics_granularity":*terraform.ResourceAttrDiff{Old:"", New:"1Minute", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "load_balancers.2970465301":*terraform.ResourceAttrDiff{Old:"", New:"arn:aws:elasticloadbalancing:us-east-1:910031756169:loadbalancer/app/devops-alb/8e90661c5ec12bf1", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "vpc_zone_identifier.1713328914":*terraform.ResourceAttrDiff{Old:"", New:"subnet-0d5bc850", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "vpc_zone_identifier.1942734813":*terraform.ResourceAttrDiff{Old:"", New:"subnet-8ee8b8ea", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "force_delete":*terraform.ResourceAttrDiff{Old:"", New:"true", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "protect_from_scale_in":*terraform.ResourceAttrDiff{Old:"", New:"false", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "vpc_zone_identifier.1988446959":*terraform.ResourceAttrDiff{Old:"", New:"subnet-570d9278", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "tag.#":*terraform.ResourceAttrDiff{Old:"", New:"1", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "tag.18571221.propagate_at_launch":*terraform.ResourceAttrDiff{Old:"", New:"true", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "arn":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "tag.18571221.value":*terraform.ResourceAttrDiff{Old:"", New:"asg-instance", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "min_size":*terraform.ResourceAttrDiff{Old:"", New:"2", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "load_balancers.#":*terraform.ResourceAttrDiff{Old:"", New:"1", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "target_group_arns.#":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "desired_capacity":*terraform.ResourceAttrDiff{Old:"", New:"4", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "vpc_zone_identifier.#":*terraform.ResourceAttrDiff{Old:"", New:"4", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "vpc_zone_identifier.3310987413":*terraform.ResourceAttrDiff{Old:"", New:"subnet-b77b5ffc", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "health_check_grace_period":*terraform.ResourceAttrDiff{Old:"", New:"300", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "default_cooldown":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "name":*terraform.ResourceAttrDiff{Old:"", New:"asg-devopslc-20180111183839904000000003", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Sensitive:false, Type:0x0}, "launch_configuration":*terraform.ResourceAttrDiff{Old:"", New:"devopslc-20180111183839904000000003", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}, "max_size":*terraform.ResourceAttrDiff{Old:"", New:"4", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Sensitive:false, Type:0x0}}, Destroy:false, DestroyDeposed:false, DestroyTainted:false, Meta:map[string]interface {}(nil)}
### Expected Behavior
<!--
What should have happened?
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### Actual Behavior
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What actually happened?
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### Steps to Reproduce
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Please list the full steps required to reproduce the issue, for example:
1. `terraform init`
2. `terraform apply`
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### Additional Context
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### References
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Are there any other GitHub issues (open or closed) or Pull Requests that should be linked here? For example:

- hashicorp/terraform#6017

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[bflad]

This issue was automatically closed by the documentation update in #3897. The configuration fix for diffs didn't match during apply and Mismatch reason: attribute mismatch: availability_zones.XXXXXX is to remove availability_zones configuration if vpc_zone_identifier is also specified. If you must specify availability_zones due to being used in a module that works with both EC2-Classic and VPC, availability_zones can be set to [] (an empty list).

[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!