Error coming while executing the script: Error: value must be known

[jiten-kmar]

Getting the following error when executing Terraform Apply
[9:44 PM] Jitender Kumar

module.gke.random_string.cluster_service_account_suffix: Creating...
module.gke.random_string.cluster_service_account_suffix: Creation complete after 0s [id=qplv]
module.gke.random_shuffle.available_zones: Creating...
module.gke.google_service_account.cluster_service_account[0]: Creating...
module.gke.random_shuffle.available_zones: Creation complete after 0s [id=-]

Error: value must be known

[basphilippus]

I am also experiencing this issue with version 14.0.0. Pinning the version to 13.1.0 works for me.

[bharathkkb]

Hi @jitender1278 @basphilippus
Could you share an example config I can use to reproduce the issue

[basphilippus]

Hi @bharathkkb,

I can reproduce the issue with the following config:

main.txt

Let me know if you need anything else.

[jiten-kmar]

yes, 13.1.0 works but 14.0.0 fails. we should get this fixed

[shanedownes-dmi]

I started running into this issue recently. In my case, downgrading to 13 alone did not resolve it. I usually use the -out flag on the plan command, and then reference it when applying. When I applied without specifying a pre-generated plan file, it worked as expected.

I suspect that a value is re-evaluated after generating the initial plan. Not sure if it's a bug, or known limitation.

[bharathkkb]

@basphilippus thanks, I tried https://gist.github.com/bharathkkb/ef9ee3facfcdc93621964f46ebb9a8eb (your example with minimal modifications) and was able to repro for TF 0.14.5, works okay with 0.13.5 which is why our CI did not flag this.

@morgante looks like the issue is the dynamic blueprint name, hardcoding that seems to resolve for 0.14.5

[rwkarg]

Would it be a good idea to put a cap on the supported terraform version matching the highest version tested in CI?

https://github.com/terraform-google-modules/terraform-google-kubernetes-engine/blob/master/versions.tf#L23

[morgante]

@bharathkkb Sounds like a core regression, let's file an upstream bug.

@rwkarg We did that historically but the reality is that in the vast majority of cases it is forward-compatible and people complain when you can't use the latest Terraform version.

[bharathkkb]

@morgante will do, after some more debugging seems to only happen when using a local. A quick fix seems to be to remove the locals and do it inline which seems to work on 0.14.5

module_name = "blueprints/terraform/${join("/", compact([var._parent_module, "terraform-google-kubernetes-engine/v14.0.0"]))}"

[bharathkkb]

@basphilippus @jitender1278 @rwkarg @shanedownes-dmi release 14.0.1 should contain the fix for this

[jiten-kmar]

Thank you so much