I have started playing with Docker and I thought it would be a good idea to share my experiments on GitHub. If you want to know a bit more about how these experiments have started, see my blog post "A dockerized policy hub"
Proof of concept of implementing a CFEngine policy hub in a docker container.
To build this image enter the cf-serverd directory and run
docker build -t bronto/cf-serverd:3.7.2 .
You must provide your own masterfiles in the container's
/var/cfengine/masterfiles and a suitable configuration for cf-serverd
in /var/cfengine/inputs. You can do that by either mounting a local
filesystem inside the container, or building your own image with the
policy files bundled inside.
You also need to keep the encryption keys so that the clients don't need
to be re-bootstrapped each time you create a new image. Again, you can
mount /var/cfengine/ppkeys from a local filesystem, or bundle your set of
encryption keys in the container itself.
This container exposes the port 5308/TCP to make cf-serverd available
outside the container. You'll want to use either the -P or the -p option
to docker run
Refer to the blog post for more information.
Dockerfile for a debian container running the systemd init system. Heavily borrowed from dockerimages/docker-systemd.
You can use it as a base image to build containers that need to run more than one process. As such, you probably won't run it alone as it does nothing useful but starting systemd...
To build this image you'll enter the debian-systemd directory and run:
docker build -t bronto/debian-systemd .
When you run this image or any container you build upon it, you'll need
at least the following options for docker run:
--cap-add=SYS_ADMIN -v /sys/fs/cgroup:/sys/fs/cgroup:ro
The whole point of having an init system running in a container is for those cases where you have processes that expect to log through a syslog service that is running on the same node. In those cases you need to run a syslog daemon in addition to the process you want to "containerize". I was interested in seeing that it is actually possible, so I built on both the cf-serverd and the debian-systemd containers.
The result is an image whose containers run systemd which, in turn, spawns CFEngine daemons and a syslog daemon. Like in the other case it does nothing useful unless you provide masterfiles, configurations for cf-serverd, and possibly encryption keys.
To build this image you'll enter the debian-systemd directory and run:
docker build -t bronto/poc-systemd .
When you run this image or any container you build upon it, you'll need
at least the following options for docker run:
--cap-add=SYS_ADMIN -v /sys/fs/cgroup:/sys/fs/cgroup:ro
In addition you'll want to use either the -P or the -p option
to docker run to expose cf-serverd outside the container.