Terraform-provider-aws: instances always need vpc_security_group_ids updated

[clippermadness]

Terraform Version

Terraform v0.10.6
AWS plugin: aws_v1.0.0_x4

Affected Resource(s)

• aws_instance.vpc_security_group_ids

Terraform Configuration Files

resource "aws_security_group" "portal_apptier_dev" {
  name        = "portal_apptier_dev"
  description = "Portal app security group"
  vpc_id      = "${data.aws_vpc.target.id}"
}

resource "aws_instance" "portal_dev1" {

  ami = "${data.aws_ami.ubuntu_20170811.id}"
  instance_type = "t2.micro"

  count = 1

  vpc_security_group_ids = ["${aws_security_group.portal_apptier_dev.id}"]

  iam_instance_profile = "${aws_iam_instance_profile.portal_dev1_instance_profile.name}"
  associate_public_ip_address = true
  key_name = "rich"

  root_block_device {
    volume_type = "gp2"
    volume_size = "32"
  }

  tags {
    Name = "portal${count.index + 1}.dev1"
  }
}

Debug Output

https://gist.github.com/clippermadness/7993969b9b8bdda2883f89fdf9c9456a

Steps to Reproduce

1. terraform plan - shows vpc_security_group_ids to update
2. terraform apply - changes the vpc_security_group_ids
3. terraform plan - still shows vpc_security_group_ids need to be updated

[roman-vynar]

Upgraded TF from 0.9.11 to 0.10.7.
Getting the same for every instance:

  ~ aws_instance.XXX
      vpc_security_group_ids.#:          "0" => "1"
      vpc_security_group_ids.852560208:  "" => "sg-YYY"

Always shown as to be updated.

[clippermadness]

I still have the issue after upgrading to Terraform 0.10.7.

[andrewchen5678]

ran into the same issue today with Terraform v0.10.7

[aerinblue]

Same issue here.

[klaus993]

Same issue here. #1911 definitely fixes it! Hope it gets merged soon.

[ikuwow]

Same issue exists in v0.11.1.

[bflad]

Hi everyone! Sorry you have been having trouble with this aws_instance bug relating to vpc_security_group_ids. It turns out this has been reported and discussed in quite a few separate issues (#1445, #1799, #1993, #2034, #2036, #2319). In order to consolidate efforts, I am closing everything except #1993 which seems to have the most thorough information at the moment. I would suggest voting on and following that issue for future updates.

Due to the high volume of reports surrounding this, the maintainers will be looking into this sometime in the near future (including the already open PRs: #1911, #2338). There are some nuances around this configuration that make it harder than a quick fix and we certainly do not want to make the situation worse. We'll keep you updated.

As a friendly reminder: voting with 👍 reactions on the original issue/PR comment is the best way to get our attention.

[bflad]

This has been released in terraform-provider-aws version 1.9.0. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[hashibot[bot]]

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!