I got this error, all at once, about 25 of them at the same time.
time="2021-03-16T23:51:59-07:00" level=error msg="Error occurred during watcher callback: unable to read directory /mnt/traefik/config/: open /mnt/traefik/config/: too many open files" providerName=file
There defiantly was not too many files.. can someone shed some light on this error and point me in some directions to look as to what is causing it.
Seems that you are hitting operating system limits. You need to increase the limits per user by modifying /etc/security/limit.conf and also system-wide by updating fs.file-max kernel directive.
Additionally, if you run Traefik through Systemd service you have to also update the script in a [Service] section by adding LimitNOFILE=<value>
You can check if your changes are correctly applied by checking the file cat /proc/<Traefik_PID>limits and Max open files directive.
if someone has that problem in the future checkout that values if changing open file limits doesn't work witch sysctl -a | grep "value":
user.max_inotify_instances
user.max_inotify_watches
linux has a kernel limit of how many files can watch an user and/or system, not just for an open files
you can change that from /etc/sysctl.conf and executing sysctl -p (permanent change)
or you can dynamically change these values executing sysctl value=somevalue (temporal change, not saved when the system is rebooted)