Add ability to cancel runs

[lusu007]

[meyfa]

So far I have not found a way to implement this. Even if we exec into the pod, there is no way to terminate Renovate without the pod being marked as "Failed", and subsequently getting restarted.

ps aux inside the pod shows the following process hierarchy:

USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
ubuntu         1  0.0  0.0   2368  1024 ?        Ss   21:08   0:00 dumb-init -- renovate
ubuntu         7  0.0  0.0   5736  3328 ?        Ss   21:08   0:00 /bin/bash /usr/local/bin/renovate
ubuntu         8  0.0  0.0   5736  3328 ?        S    21:08   0:00 /bin/bash /usr/local/bin/node /usr/local/renovate/dist/renovate.js
ubuntu         9 49.1  9.5 32835976 774928 ?     Sl   21:08   2:40 /opt/containerbase/tools/node/18.20.3/bin/node --use-openssl-ca /usr/local/renovate/dist/renovate.js

No matter which of these processes I terminate (kill -s SIGTERM <pid> or kill -s SIGKILL <pid>), the pod is marked as failed - which makes sense, I guess.

However, this leads me to believe we can only "cancel" a run by deleting the Job itself - not the Pod. In that case, any logs would be gone, along with any trace of this action being performed. This seems bad from a monitoring/auditability perspective.

[meyfa]

I suppose in theory we could override the command of the Renovate container so that it runs Renovate as usual, but traps SIGTERM & exits gracefully. This might work for runs triggered manually via the Foreman UI, at least. Arguably it's more likely someone wants to cancel a manual ran than a scheduled run. However, this seems like a fragile implementation at best.