Ever wondered if you can get
systemd running in a Docker container? Apparently Dan Walsh did, and spent some time getting it to work.
While working with Docker, I looked at the great work that Scott Collier was doing for getting services to run within a container. Scott provides the fedora-dockerfiles package in docker with lots of “Dockerfile” examples. You can build Docker images by running “docker build” on these examples.
It seemed a little difficult, and wondered if getting systemd to run within a docker container, as I did with virt-sandbox-service, might make this simpler.
The Docker Model suggests that it is better to run a single service within a container. If you wanted to build an application that required an Apache service and a MariaDB database, you should generate two different containers. Some people insist on running multiple services within a container, and for this Docker suggested using the supervisord tool. In RHEL we do not want to support supervisord, since it is written in Python, and do not want to pull a Python requirement into containers, and it is just a package used to monitor multiple services. We already have a tool for monitoring multiple services called systemd.
After a little trial and error, Dan got
systemd working within a container on Fedora Rawhide, and expects it will work on Fedora 20 or RHEL 7 (when it’s released). Give it a spin and let Dan know how it works out for you.