docker usage left pid file alive in case of crash

[jupe]

Note that this issue is not obvious library bug, more like opening discussion around topic.

background: https://petermalmgren.com/signal-handling-docker/

use case:
pid library is used inside docker so that lock files are stored to mounted folder that host holds (not inside docker). Library lock down physical resource for test usage while tests are running. pid file is destroyed normally when tests ends but if for some reason test crashes pid module doesn't have chance to remove pid file and file left behind. This process pid is always 1 because of it's running inside docker.

problem:
if process dies and pid file with pid 1 left behind it means that next process thinks pid file is still valid and resource cannot be used until pid file is destroyed separately.

This is annoying issue that luckily happens rarely but haven't figure out yet any good solution to avoid such problem.

[jupe]

simple workaround for this is to use --pid=host docker option.