[xorcist]

> "println()" then push that out as a change

No, when you actually need to debug in production that's usually not what you want. Changing or restarting the software you are debugging might well make the behaviour you want to understand go away.

> introduce tracing

Yeah, well, that's basically "logging in". Just over less mature and likely less secure protocol than SSH.

You don't need ptrace and tcpdump to debug software. It's just that it can shave a few weeks off your time when you need to reproduce something in the more tricky cases.

These discussions tend to surface in the context of containers but that's all very irrelevant. You need to debug software isn't affected by the way you package it.