Chains section in TektonConfig gets override with default

[gbenhaim]

Expected Behavior

User provided configuration for Tekton Chains should be preserved.

Actual Behavior

When creating a TektonConfig with user provided configurations for chains, the operator overrides the values in the TektonConfig.

Example config the gets overriden:

---
apiVersion: operator.tekton.dev/v1alpha1
kind: TektonConfig
metadata:
  name: config
spec:
  profile: basic
  targetNamespace: tekton-pipelines
  pruner:
    resources:
    - pipelinerun
    - taskrun
    keep: 100
    schedule: "0 8 * * *"
  chain:
    artifacts.oci.storage: oci
    artifacts.pipelinerun.format: in-toto
    artifacts.pipelinerun.storage: oci
    artifacts.taskrun.format: in-toto
    artifacts.taskrun.storage: ""
    transparency.enabled: "false"

Steps to Reproduce the Problem

1. Install the Tekton operator
2. Create a TektonConfig with custom values for chains (for example the config above)

Additional Info

• Kubernetes version:

  Output of kubectl version:

Server Version: version.Info{Major:"1", Minor:"29", GitVersion:"v1.29.2", GitCommit:"4b8e819355d791d96b7e9d9efe4cbafae2311c88", GitTreeState:"clean", BuildDate:"2024-02-14T22:24:00Z", GoVersion:"go1.21.7", Compiler:"gc", Platform:"linux/amd64"}

• Tekton Pipeline version:

  Output of tkn version or kubectl get pods -n tekton-pipelines -l app=tekton-pipelines-controller -o=jsonpath='{.items[0].metadata.labels.version}'

Client version: 0.33.0
Chains version: v0.20.0
Pipeline version: v0.56.1
Triggers version: v0.26.1
Operator version: v0.70.0

I think that the issue is that the pipelines operator runs its pre-upgrade logic after the tetkon config is created, but before it creates the TektonChains CR (https://github.com/tektoncd/operator/blob/main/pkg/reconciler/shared/tektonconfig/upgrade/pre_upgrade.go#L33), because of that the default values of chains configuration are written to the tekton config.
I saw the the pre-upgrade logic is running by turning on debug logging:

{"level":"debug","logger":"tekton-operator-lifecycle.upgrade","caller":"upgrade/upgrade.go:89","msg":"executing pre upgrade functions","commit":"2014719-dirty","knative.dev/pod":"tekton-operator-54f9b585dd-xlv8f","knative.dev/controller":"github.com.tektoncd.operator.pkg.reconciler.shared.tektonconfig.Reconciler","knative.dev/kind":"operator.tekton.dev.TektonConfig","knative.dev/traceid":"e29a3087-faa9-47f9-9db6-2d068254dbf5","knative.dev/key":"config","numberOfFunctions":2}

{"level":"debug","logger":"tekton-operator-lifecycle.upgrade","caller":"upgrade/upgrade.go:105","msg":"completed pre upgrade execution","commit":"2014719-dirty","knative.dev/pod":"tekton-operator-54f9b585dd-xlv8f","knative.dev/controller":"github.com.tektoncd.operator.pkg.reconciler.shared.tektonconfig.Reconciler","knative.dev/kind":"operator.tekton.dev.TektonConfig","knative.dev/traceid":"e29a3087-faa9-47f9-9db6-2d068254dbf5","knative.dev/key":"config"}

https://github.com/tektoncd/operator/blob/main/pkg/reconciler/shared/tektonconfig/upgrade/upgrade.go#L34
https://github.com/tektoncd/operator/blob/main/pkg/reconciler/shared/tektonconfig/upgrade/upgrade.go#L89