backend: Replace context.TODO() with explicit background context in long-running goroutine

[itvi-1234]

Summary

This PR cleans up technical debt in the Golang backend inside the drainNode asynchronous API handler. It replaces repeated context.TODO() usages with the correctly initialized, explicit context.Background() wrapper variable ctx that the goroutine actually instantiated but failed to pass downstream.

Changes

• backend/cmd/headlamp.go: Inside the drainNode goroutine, replaced context.TODO() in Kubernetes nodeClient and clientset.CoreV1().Pods() calls with the available ctx variable to explicitly signify that this work outlives the HTTP request scope.

[k8s-ci-robot]

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[itvi-1234]

Hi @sniok @vyncent-t @skoeva This is a small code cleanup. It replaces the temporary context.TODO() placeholders with the proper ctx (context.Background()) variable that was already defined at the start of the function.

Because Node Draining takes a long time, it runs in the background. Using the correct background context ensures the draining process safely finishes its job, even if the user accidentally closes their browser before it completes. Could you please review this PR , lemme know if any changes needed 🚀

[Copilot]

Pull request overview

This PR updates the backend node-drain async goroutine to consistently use its explicitly created context.Background() (ctx) instead of context.TODO() when calling Kubernetes client APIs, making the intended “outlives request scope” behavior explicit and consistent.

Changes:

• Use the goroutine’s ctx for Nodes().Get and Nodes().Update.
• Use the same ctx for listing and deleting pods during the drain operation.

[itvi-1234]

Hi @illume , @sniok The PR looks fine , lemme know if any changes needed

[itvi-1234]

Hi @sniok , any directions regarding this PR