Revert "Merge pull request #1314 from estroz/autoscaling-group-tags"

[estroz]

This reverts commit b018c80, reversing changes made to d684cca.

When running terraform plan to deploy a cluster, the following error message is received:

1 error(s) occurred:

* variable tectonic_autoscaling_group_extra_tags should be type list, got map

Comments like hashicorp/terraform#7705 (comment) indicate that terraform cannot handle complicated data structures, such as lists of maps whose structures are not explicitly declared, i.e. user-created variables. Therefore the changes created by b018c80 should be reverted until lists of arbitrary maps are supported. In the meantime a workaround will be created and merged.

[sym3tri]

@estroz what was the workaround?

[estroz]

@sym3tri users must manually tag their autoscaling groups. I can make a PR documenting this if you'd like.

[s-urbaniak]

This is very strange, but I believe I have the explanation. We are generating a JSON based terraform.tfvars file.

Using a list of maps is fine in HCL syntax (I am using the following for all my clusters):

tectonic_autoscaling_group_extra_tags = [
  {
    key = "expirationDate",
    value = "yyyy-mm-dd",
    propagate_at_launch = true,
  },
]

When I convert the above to JSON syntax:

{
  "tectonic_autoscaling_group_extra_tags": [
    {
      "key": "expirationDate",
      "propagate_at_launch": true,
      "value": "yyyy-mm-dd"
    },
  ],
}

Then I also get the same reported error:

1 error(s) occurred:

* variable tectonic_autoscaling_group_extra_tags should be type list, got map

This error message doesn't make any sense, until we convert the above using https://github.com/kvz/json2hcl (which simply uses the Terraform JSON parser) back to HCL:

"tectonic_autoscaling_group_extra_tags" = {
  "key" = "expirationDate"

  "propagate_at_launch" = true

  "value" = "yyyy-mm-dd"
}

One can see, that the JSON parser simply omitted the list declaration and generated a simple map. Now the error message makes total sense.

[s-urbaniak]

Other interesting failure cases. When I declare two list entries like this:

  "tectonic_autoscaling_group_extra_tags": [
    {
      "key": "expirationDate",
      "propagate_at_launch": true,
      "value": "2017-09-20"
    },
    {
      "key": "foo",
      "propagate_at_launch": true,
      "value": "bar"
    }
  ],

Terraform generates two HCL variables of the same name:

"tectonic_autoscaling_group_extra_tags" = {
  "key" = "expirationDate"

  "propagate_at_launch" = true

  "value" = "2017-09-20"
}

"tectonic_autoscaling_group_extra_tags" = {
  "key" = "foo"

  "propagate_at_launch" = true

  "value" = "bar"
}

The terraform plan error message here obviously also makes sense:

invalid value "terraform.tfvars" for flag -var-file-default: multiple map declarations not supported for variables

[lucab]

For reference hashicorp/hcl#209.

[s-urbaniak]

Another reference hashicorp/terraform#15549

[s-urbaniak]

two ways out of this:

• we generate terraform.tfvars in HCL syntax (which supports lists of maps)
• we fix the JSON parser (that's obviously the cleaner way)