An Overview on s390x Base Images

For s390x, quite a few options for base images are available on Docker Hub/Docker Store these days. They vary from enterprise environments over community distributions to minimal images. This post gives an overview on what is provided by various sources.

Docker CE for all distributions

The previous post mentioned that Docker provides CE packages for Ubuntu. For users of Debian, SLES, RHEL, Fedora, ClefOS, openSUSE, and Alpine, there is still an option to get the latest Docker CE version to their environment:

First CE for s390x by Docker

Today, Docker CE v17.06 has been released. It offers a series of enhancements as laid out in their announcement blog post. However, there is one more thing: the release comes with s390x binaries. Out of the three major enterprise distributions supported on the mainframe, Docker offers CE for Ubuntu. Particularly, Docker CE is not provided for SLES and RHEL (on any platform). Accordingly, binaries are available for Ubuntu for IBM z Systems.
(Note: See the next post if your distribution of choice happens to be something else than Ubuntu.)

Docker 1.12 builds for Ubuntu

Ubuntu has built Docker 1.12 binaries, which target latest and greatest, but can be used on 16.04. Since Docker 1.12 has been split into docker, containerd and runc, there are three packages that need to be installed.

A Private Registry. Building and Using

Recently, I received some questions on how to create a private registry. Specifically when going to a recent version, building on your own might make sense. Since describing this last (here and here), this can even be done simpler.

Let's start the build:

Docker 1.11.2 for RHEL 7 (and Ubuntu 16.04)

A new version of Docker is linked to from developerWorks. This is a bump to 1.11.2, built on/for RHEL 7.2 (which happens to be the version that Canonical also provides in universe for Ubuntu 16.04

Application Containers, System Containers

Canonical's Ubuntu 16.04 comes with LXD as "Linux container hypervisor". What is LXD and how does it differ from docker?

LXD is typically for system containers, Docker is usually an application container approach.

Ubuntu 16.04 GAes and Provides Containers

Today, Ubuntu 16.04 LTS for Server is available for s390x (and a few other minor platforms :-). It provides a few interesting infrastructure options: besides OpenStack and KVM, it offers system containers with LXC/LXD; for application containers, it comes with Docker. Some aspects of what this introduces will follow here...

s390x/ubuntu:16.04 on Docker Hub

With https://hub.docker.com/r/s390x/ubuntu/, the first Ubuntu 16.04 image just appeared on DockerHub

Closing Another Base Image Gap

Most recently, I mentioned (here and here) how to best deal with the fact that Ubuntu is widely used as base image, but does not exist on z Systems. A sufficiently close Debian is a decent solution for that.

Today's announcement at LinuxCon shows how this will get even easier: Ubuntu will be made available on z Systems. This will make all "FROM ubuntu" images no-brainers.

Portability Series: Another Base Image

In the previous post, we looked at various challenges when moving existing (read: x86) container setups onto z Systems. One challenge is the widespread use of Ubuntu as Docker base images. The closest thing on z is Debian having roughly the same packaging structure and naming.

Let's have a look how we can easily get to such an environment.