As per the guide, running those restart commands should only be necessary if you change the population of plugins (e.g. by removing or adding a valid symlink). Otherwise, Rails should detect code changes and restart its processes. It might be possible to turn off this behaviour in configuration, but that should be the default.
Here’s an example of the automated restart, albeit on a non-docker dev install, but the behaviour should be similar:
[DEV]: Edited files which are not autoloaded. Restarting server...
- plugins/discourse-multilingual/extensions/post.rb
RESTARTING UNICORN
I, [2022-06-15T13:25:29.082415 #227981] INFO -- : reaped #<Process::Status: pid 228047 exit 0> worker=0
I, [2022-06-15T13:25:29.082642 #227981] INFO -- : reaped #<Process::Status: pid 228048 exit 0> worker=1
I, [2022-06-15T13:25:29.082788 #227981] INFO -- : reaped #<Process::Status: pid 228049 exit 0> worker=2
I, [2022-06-15T13:25:29.082877 #227981] INFO -- : master complete
I, [2022-06-15T13:25:29.947587 #228661] INFO -- : Refreshing Gem list
Got TERM signal
Shutting down
Terminating quiet threads
Scheduler exiting...
Pausing to allow jobs to finish...
Bye!
Starting CSS change watcher
I, [2022-06-15T13:25:38.326511 #228661] INFO -- : listening on addr=0.0.0.0:3000 fd=25
I edited the file post.rb and hit save, the rest is automated.
Sorry I don’t have access to my docker based dev machine where I am at present to confirm this is the case on the docker install too, but recall that it is, unless something changed.