Testing Systemd Services on Arch, Fedora, and Friends

Following up on a previous post about how to test systemd services with docker-compose on Ubuntu, I spent some time recently trying to do the same thing with a few other Linux distributions. I was able to get the same tricks to work on these other distributions:

• Amazon Linux
• Arch
• CentOS
• Debian
• Fedora
• openSUSE
• RHEL

A few of those distros required an additional tweak, however.

One more tmpfs directory for Arch and Fedora

For Arch and Fedora, I had to do one more thing: add /tmp as a tmpfs mount.

So the docker-compose.yml file for those distros should look like this:

version: '3' services: my_test_container: build: . image: my_test_image tmpfs: - /run - /run/lock - /tmp volumes: - /sys/fs/cgroup:/sys/fs/cgroup:ro

Or when running as a regular docker command, start the container like this:

docker run \ --tmpfs /run --tmpfs /run/lock --tmpfs /tmp \ --volume /sys/fs/cgroup:/sys/fs/cgroup:ro \ --detach --rm \ --name my_test_container my_test_image

Different init script location for openSUSE

For openSUSE, the systemd init script is located at /usr/lib/systemd/systemd instead of just /lib/systemd/systemd. So the Dockerfile I used for it looks like this:

FROM opensuse/leap:15 RUN zypper install -y systemd CMD ["/usr/lib/systemd/systemd"]