damianoneill/centos-systemd repository overview

⁠docker-centos-systemd

Dockerfile for systemd base image

Systemd is now included in both the centos:7 and centos:latest base containers, but it is not active by default. This Dockerfile deletes a number of unit files which might cause issues. From here, you are ready to build your base image.

 $ docker build --rm -t local/docker-centos-systemd .

In order to use the systemd enabled base container created above, you will need to create your Dockerfile similar to the one below.

 FROM local/docker-centos-systemd
 RUN yum -y install httpd; yum clean all; systemctl enable httpd.service
 EXPOSE 80
 CMD ["/usr/sbin/init"]

Build this image:

 $ docker build --rm -t local/docker-centos-systemd-httpd

In order to run a container with systemd, you will need to mount the cgroups volumes from the host. Below is an example command that will run the systemd enabled httpd container created earlier.

 $ docker run -ti -v /sys/fs/cgroup:/sys/fs/cgroup:ro -p 80:80 local/docker-centos-systemd-httpd

This container is running with systemd in a limited context, with the cgroups filesystem mounted.