Checkmk running in Docker times out while activating changes

Owned by Sebastian Kirchmeyer
Last updated: Oct 20, 2023 by Matthew Hierholzer
When running Checkmk in a Docker container, setting the User limit for nofile to a far smaller value than default is highly recommended.

LAST TESTED ON CHECKMK 2.0.0P1

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Information

When starting the container, you can set this with the following option

--ulimit nofile=1024


The entire command might look like this:

docker container run -dit -p 8080:5000 --ulimit nofile=1024 --tmpfs /opt/omd/sites/cmk/tmp:uid=1000,gid=1000 -v monitoring:/omd/sites --name monitoring -v /etc/localtime:/etc/localtime:ro --restart always checkmk/check-mk-raw:1.6.0-latest


This is also described in our official guide, and we urgently recommend reading the following two articles in their entirety when running Checkmk in Docker:

Installation as a Docker-Container

Checkmk server in a Docker container

The modification of ulimit is also possible in Docker swarm. Compare: https://github.com/moby/moby/issues/40639