&gt;And yet it happens.<p>I can understand that argument. It&#x27;s an edge case, and building a sane Dockerfile on top of Alpine that runs applications through S6 (or runit), which developers use for their applications is the way to go for me. This is what phusion baked in?<p>&gt;The SSH server is incredibly useful [...] (although it&#x27;s not really necessary anymore with docker exec).<p>It&#x27;s an additional attack vector and, by your own admission, it&#x27;s useless. docker exec has been baked into docker for over a year.<p>&gt;Or just run [cron] in-container to keep your service clusters together.<p>Per-container cron sounds painful. Then you have to deal with keeping every container&#x27;s system time in sync with the host (yes, they can deviate). Not only that, if you have a periodic cron job that runs an app to update some database value, scaling becomes bottlenecked and race conditions (and data races) can get introduced. You are prevented from running multiple instances of one application to alleviate load because the container has the side-effect of running some scheduled job. Cron should be separate.<p>One can also choose the degree to which they want to throw out good practices that prevent them from repeating others&#x27; mistakes.