Improve docs

[ctcjab]

The README appears to be the only documentation for this software, and doesn't currently cover some key use cases.

(For example, I just tried supercronic for the first time and am seeing the warning "process reaping disabled, not pid 1" logged, but there is no mention in the docs of process reaping, the implications of having it disabled, what to do to enable it, etc. There is an unrelated mention that "Supercronic needs to be PID 1" to enable supercronic to reload crontabs when appropriate signals are delivered to the container, but again, no docs on or example of how to do that.)

Proposing this ticket to track improving the docs, ideally with a comprehensive description of supercronic's features, usage, and configuration available on a dedicated docs site, or at least in the README.

[andyg2]

Here's my understanding of this but I don't know enough about the inner workings of Supercronic to confirm this is precise enough.

Process reaping refers to the cleanup of zombie processes (defunct processes) that were created when a child process (a scheduled job) finished execution but was not properly waited on by its parent process.

How It Happens:
A cron job starts – A child process is created to execute a scheduled job.
The child process completes – When the job finishes, it sends a signal to the parent and enters a "zombie" state.
Reaping the process – The parent should call wait() or waitpid() to collect the exit status of the finished child process and remove it from the process table.

Why Reaping Matters:
If cron daemon does not reap zombie processes, they accumulate in the process table, consuming system resources.

[qianlongzt]

"process reaping disabled, not pid 1"

Just ignore it; reaping should only happen when the PID is 1. Changing the log level to 'info' would be more reasonable.