Someone asked on IRC about running ntpd in a container on Atomic, so I’ve put together a small example. We’ll start with a very simple Dockerfile:

FROM alpine
RUN apk update
RUN apk add openntpd
ENTRYPOINT ["ntpd"]

I’m using the alpine image as my starting point because it’s very small, which makes this whole process go a little faster. I’m installing the openntpd package, which provides the ntpd binary.

By setting an ENTRYPOINT here, the ntpd binary will be started by default, and any arguments passed to docker run after the image name will be passed to ntpd.

Next week is the Red Hat Summit in Boston, and I’ll be taking part in a Project Atomic presentation in which I will discuss various (well, two) options for deploying Atomic into an OpenStack environment, focusing on my heat-kubernetes templates.

As part of that presentation, I’ve put together a short demonstration video:

This shows off the autoscaling behavior available with recent versions of these templates (and also serves as a very brief introduction to working with Kubernetes).

While experimenting with Fedora Atomic, I was looking for an elegant way to automatically deploy Atomic into an OpenStack environment and then automatically schedule some Docker containers on the Atomic host. This post describes my solution.

Like many other cloud-targeted distributions, Fedora Atomic runs cloud-init when the system boots. We can take advantage of this to configure the system at first boot by providing a user-data blob to Nova when we boot the instance. A user-data blob can be as simple as a shell script, and while we could arguably mash everything into a single script it wouldn’t be particularly maintainable or flexible in the face of different pod/service/etc descriptions.