Injected sidecars still can show up in TaskRun status when the TaskRun has explicit sidecars

[abayer]

Expected Behavior

If a pod has a container injected into it by some non-Tekton method, such as a mutating webhook, as well as explicitly defined sidecars, that container should not show up in taskRun.Status.Sidecars.

Actual Behavior

Any container in the pod which doesn't start with step- is treated as a sidecar by the TaskRun reconciler's updateStoppedSidecarStatus function. If there are also explicitly specified sidecars in the TaskRun, the podconvert.IsSidecarStatusRunning call after StopSidecars will return true if the explicit sidecar(s) weren't already terminated, resulting in updateStoppedSidecarStatus getting called.

MakeTaskRunStatus correctly filters to only include step- and sidecar- containers, but updateStoppedSidecarStatus doesn't have that filtering.

Steps to Reproduce the Problem

1. Inject a container into a TaskRun pod without specifying it as a step or sidecar, with the TaskRun containing at least one explicit sidecar.
2. Wait for the pod to complete, and see that the injected sidecar container shows up in the TaskRun status, but was not present in the status until the sidecars were stopped.

Additional Info

• Tekton Pipeline version:

Every version I've checked through the latest v0.56.0.

[abayer]

Looking deeper into the code, I see that we are very deliberately stopping injected "sidecars", but I still think they shouldn't show up in the TaskRun.Status.Sidecars - #5565 (comment) seems to agree with me. =) Looks like we just missed the updateStoppedSidecarStatus angle in the original PR.

[abayer]

Also, this only happens when the TaskRun has explicit sidecars as well as injected sidecars - otherwise updateStoppedSidecarStatus never gets called. Updated the issue description accordingly.