Terraform: Passing ignore_changes into a module

[nodesocket]

Is there a way to pass ignore_changes into a module. I.E. I want to ignore aws_instance.ami only for some instances of a module. I tried adding ignore_changes as a new module variable, but getting:

aws_instance.instance: lifecycle ignore_changes cannot contain interpolations

# in module
lifecycle {
    ignore_changes = [
      "${var.ignore_changes}",
    ]
  }

[sworisbreathing]

I've just run into this same issue. in my case I've got AWS CodePipeline doing CI/CD for a lambda function in my dev account, and I don't want terraform to overwrite the version deployed in dev, but in prod I want to lock it down and be more explicit about which version I'm running. So I want to do something like:

lifecycle {
  ignore_changes = "${var.environment == "prod" ? list() : list("s3_key")}"
}

However, even in the latest build of terraform there is an explicit check preventing interpolations for lifecycle.ignore_changes

[sworisbreathing]

This issue appears to be a duplicate of #3116 (or at least, I'm assuming it will work once that issue is fixed).

@apparentlymart - since that issue is locked I can't comment on it, but is there any chance this could be revisited, given the changes to interpolation that were made in terraform 0.12?

[jaksky]

Is there any update on this or workaround?

[LukeCarrier]

The other issue with locking the other discussion is that we can't add our 👍 to the issue, thus I'm not sure we have an accurate number of how many folks are being bitten by this. Could the issue be unlocked, maybe?