Branch planner PR's assume empty state

[YentlFrickx]

I set up the tf-controller in my cluster and it works without issue for applying changes in the 'main' branch. But using the branch planner functionality I noticed that on every PR I create, it starts from an empty state instead of from the state from the main branch. This results in all resources seemingly being created for the first time, not changed or added.

[jsimpso]

I just ran into this too, it looks like it's due to how secretSuffix is being dynamically assigned in the backend config when not specified in the spec.

For a Terraform object named testing, the default secretSuffix is testing. However, for a branch-planner PR object, the default secretSuffix ends up being testing-pr-{pr_id}.

This can be worked around with the default backend by manually specifying secretSuffix in your backendConfig , e.g.

apiVersion: infra.contrib.fluxcd.io/v1alpha2
kind: Terraform
metadata:
  name: helloworld
  namespace: flux-system
spec:
  interval: 1m
  approvePlan: auto
  path: ./
  backendConfig:
    secretSuffix: helloworld
  sourceRef:
    kind: GitRepository
    name: helloworld
    namespace: flux-system

[yitsushi]

I remember an issue about it, or similar to this issue, but I can't find it. I have no idea if we fixed it (thought we fix) or just wanted to fix it.

[mnencia]

It looks like this is the commit that should fixe the issue e93dc5e

[yitsushi]

Thank you. Yes it's related. I don't know yet why it doesn't help the way we expect.

if spec.BackendConfig == nil {
	spec.BackendConfig = &infrav1.BackendConfigSpec{
		SecretSuffix:    originalTF.Name,
		InClusterConfig: true,
	}
}

One issue with this that I can see instantly, it only changes things if BackendConfig it does not apply this, which is okay in most cases, but I can see some edge cases where it fails as hard as it can (like only Labels is defined).

In other cases it literally does the same as the suggested workaround:

default backend by manually specifying secretSuffix

It sets the SecretSuffix to the same as the original TF resource name, so if that workaround works, than this patch should solve that case.

[yitsushi]

Ah, never mind. The mentioned commit landed on Sep 28, 2023, but out latest RC release was on Sep 19, 2023, so it's fixed only in main. We should really create a new release :/

So I guess it's fixed, but the fix is not released yet only merged.