Docker Check-MK Monitoring

This is a Dockerfile to set up Check-MK Monitoring (Checkmk Raw edition) along with Msmtp send-only mail (using Gmail, Mandrill, etc.) for notifications.

Build

1. Ensure the correct version from the downloads page is noted in the Dockerfile. As of version 1.5.0, Check-MK requires a tmpfs so the container must be run with either --privileged or --cap-add SYS_ADMIN with --security-opt apparmor:unconfined.

2. Build from Dockerfile:

    docker build -t check_mk .
   

3. Data volumes (check_mk_config and check_mk_data) will be created on first run if they don't already exist. Check-MK site configurations will be auto-generated in /opt/omd/sites.

4. Edit the msmtprc and msmtp-aliases files with your email SMTP info. Default site/user is omd. Copy into the check_mk_config volume:

    docker run --rm \
               --mount type=volume,source=check_mk_config,target=/config \
               -v $(pwd):/mnt \
               ubuntu:18.04
               cp msmtprc msmtp-aliases /config/
   

Run

Systemd service file is also available. Make sure to run with the --init flag to best manage the container shutdown process.

docker run -d \
           --cap-add SYS_ADMIN \
           --mount type=volume,source=check_mk_config,target=/config \
           --mount type=volume,source=check_mk_data,target=/opt/omd/sites \
           -v /etc/localtime:/etc/localtime \
           -p 5000:5000 \
           --name check_mk_run \
           --init \
           check_mk

Be patient when starting (20-40 seconds). The site has to be generated initially, then regenerated on subsequent runs to make sure all the permissions and user/groups are correct. Existing site info will not be overwritten!

The default username is cmkadmin. The password is randomly set on initial site creation. Find it with:

docker logs check_mk_run | grep password

Manage

The default site name is 'default'. You can use the omd commands to control that site:

$ docker exec -it check_mk_run /bin/bash
# omd --help
# omd su default
OMD[default]:~$ ....

Update

• Each site has to be updated to the new version while the old version is installed. Until I figure out how to automate this, it has to be done manually.

  $ docker exec -it check_mk_run /bin/bash
  # export VERSION=1.4.0p34
  # curl -o new_version.deb https://download.checkmk.com/checkmk/$VERSION/check-mk-raw-${VERSION}_0.focal_amd64.deb
  # dpkg -i new_version.deb
  # omd stop <site name>
  # omd update <site name>
  

• Now update the Dockerfile and rebuild the image with the new version and restart check_mk.