Fix container indexing bug in SetContainerImageFromRegistry function #7727

[jiridanek]

• Fix container indexing bug in SetContainerImageFromRegistry function kubeflow/kubeflow#7727

• RHOAIENG-25707: feat(webhook): read namespace annotation on Notebook CR to locate ImageStream #625 (comment)

Problem

The SetContainerImageFromRegistry function in components/odh-notebook-controller/controllers/notebook_webhook.go has a bug where it operates on the wrong slice element and drops environment variable edits.

Details

Inside the for _, container := range notebook.Spec.Template.Spec.Containers loop (around lines 756-770), the code:

1. Writes the image to notebook.Spec.Template.Spec.Containers[0], irrespective of which container actually matched the notebook name
2. Modifies the copied container variable's Env slice, but never writes it back to the parent slice, so the JUPYTER_IMAGE update is lost

Solution

Refactor to iterate with index and update in place:

-for _, container := range notebook.Spec.Template.Spec.Containers {

• if container.Name == notebook.Name {
  +for idx, container := range notebook.Spec.Template.Spec.Containers {

• if container.Name == notebook.Name {
  …

•    notebook.Spec.Template.Spec.Containers[0].Image = imageHash
  

•    notebook.Spec.Template.Spec.Containers[idx].Image = imageHash
     …
  

•    for i, envVar := range container.Env {
  

•    for i, envVar := range notebook.Spec.Template.Spec.Containers[idx].Env {
         if envVar.Name == "JUPYTER_IMAGE" {
  

•            container.Env[i].Value = imageSelection
  

•            notebook.Spec.Template.Spec.Containers[idx].Env[i].Value = imageSelection
             break
         }
     }
     …
  

  }
  }
  This guarantees the correct container is mutated and the environment variable change is persisted.

Context

This issue was identified during review of PR #625 but is a pre-existing bug unrelated to that PR's changes.

Backlinks:

• PR: RHOAIENG-25707: feat(webhook): read namespace annotation on Notebook CR to locate ImageStream opendatahub-io/kubeflow#625
• Comment: RHOAIENG-25707: feat(webhook): read namespace annotation on Notebook CR to locate ImageStream opendatahub-io/kubeflow#625 (comment)