[0xmichalis]

Summary

• v0.4.0 removed the sentinel's --mode flag together with the janitor, but templates/sentinel.yaml still passes --mode=sentinel. With sentinel.enabled=true, every sentinel pod exits with code 2 during flag parsing and crash-loops:

  $ docker run --rm --network none --entrypoint /sentinel ghcr.io/kylan11/understudy:0.4.4 --mode=sentinel --cloud=auto --surge-on-rebalance=false
  flag provided but not defined: -mode

• Drop the arg.

• Add hack/check-chart-args.sh (make chart-args-check, run in the helm CI job). It renders the chart with the sentinel enabled and runs each binary with the args its container receives plus -h, so a flag removed from a binary but still rendered by the chart fails CI instead of crash-looping on install.

Verification

• make chart-args-check fails on main (templates/sentinel.yaml passes sentinel args it does not accept, flag provided but not defined: -mode) and passes with this change.
• make chart-check, helm lint charts/understudy and shellcheck hack/check-chart-args.sh: passed.

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[kylan11]

thanks @0xmichalis for this fix and the accompanying reliability and security PRs; the regression coverage is much appreciated

I reproduced the sentinel startup failure and verified the fix. I added a small follow-up to the chart argument check: Helm render failures now propagate to the check, and unexpectedly empty argument lists are rejected. Previously, failure inside the process substitution could leave the script running only -h and incorrectly succeeding.