After overriding some configurations of /usr/share/containers/containers.conf in /etc/containers/containers.conf - e. g. log_size_max = 10485760, what is the official method to apply this new configuration with the least impact on the system?
There is enough documentation on how to configure things, but not on how to apply the configuration.
It surely works after a reboot of the whole system, but I assume that there is a less impacting way to do that.
Podman runs no daemon (unlike docker/Moby); so, there is no need to reload any daemon. The configuration that is present when podman is executed apply. In other words, as soon as you change something, it applies to all podman runs thereafter, immediately.
It cannot apply to currently running pods - podman reads its configuration when it's started! So, you'll have to restart these, if the configuration changes apply to their runtime behavior.
I don't know if this is according to the best practices or not, but the way I do it is after changing the content of this file I simply enter podman pull <some_test_image_like_nginx> to make sure the new configurations have been applied and they usually are.
According to this link apparently, there is no need to perform any specific action after reconfiguring and the changes will be automatically applied, in addition, the CONTAINERS_CONF environment variable could be used to make sure the /etc/containers/containers.conf is in use.
/etc/containers/containers.conf just to make sure the configurations have been applied everywhere. Just to be clear I restart the pods not the containers. In addition, I have to say I have never used the environment variable mentioned in the answers and the configurations have been applied for me automatically every time. I've tested this on Debian 11 only though. systemd unit files for your pods and containers restarting them via systemctl would do the job and it doesn't matter which mode you're running ( rootful/rootless ), although I have to say I always generate new systemd unit files after configuration changes because some of my changes actually change some options in the unit files.