`empty or illegal parameter` using `open_tracking: true`

[LoicMahieu]

Hi there,

First, great thanks @wgebis to have conclude my 2 previous PR (#32 #33 to #38). I was too busy for looking at that and it was lying in my todo list for a while!

I just tried the parameter open_tracking: true on an existing plan and it fails in error:

Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
  ~ update in-place

Terraform will perform the following actions:

  # module.mysuperapp_mailgun[0].mailgun_domain.default will be updated in-place
  ~ resource "mailgun_domain" "default" {
        id                    = "mysuper.domain.com"
        name                  = "mysuper.domain.com"
      ~ open_tracking         = false -> true
        # (10 unchanged attributes hidden)
    }

Plan: 0 to add, 1 to change, 0 to destroy.

Do you want to perform these actions in workspace "stable-next-m6bt8p"?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: yes

module.mysuperapp_mailgun[0].mailgun_domain.default: Modifying... [id=mysuper.domain.com]
╷
│ Error: empty or illegal parameter
│
│   with module.mysuperapp_mailgun[0].mailgun_domain.default,
│   on modules/mysuperapp_mailgun/main.tf line 35, in resource "mailgun_domain" "default":
│   35: resource "mailgun_domain" "default" {

I remember getting this kind of error when I was working on the module. But I confess, I am a pure noob in Go, I don't understand what's the problem and where I should looking for.

Do you have any advice?

Thanks

[manster18]

I have encountered the same issue. Additionally, you may encounter a problem when manually changing this parameter through the MailGun UI. In this case, I recommend adding a lifecycle block with ignore_changes for the "open_tracking" parameter.

 lifecycle {
        ignore_changes = [ open_tracking ]
    }