docker-centos7-base

Base CentOS 7 image with a few perks. This is based on the official CentOS 7 base image.

Building this results in an updated CentOS image with a few extra packages:

net-tools
tar
wget
unzip
EPEL repo
pwgen (from EPEL)

What is it for?

Most images we find at the public Docker Hub are Ubuntu-based. Nothing against Ubuntu, but Redhat customers fell more at home with CentOS.

A work is in progress to convert, migrate and adapt some useful images around to CentOS-based distributions. The list below will be updated accordingly.

darrynvantonder/docker-java7
darrynvantonder/docker-tomcat7
darrynvantonder/docker-mysql
darrynvantonder/docker-redis
darrynvantonder/docker-node

But I need RHEL images!

Please note that nearly all images under my repository are derived from this one, so it would be very easy to simply change the FROM clause in its own Dockerfile in order to use the RHEL 7 official base image. Rebuilding the derived images would be a piece of cake.

The RHEL 7 official base image can be downloaded from Redhat and installed with "docker load" and tagged with whatever name you like.

As far as I know, RHEL 7 containers are covered by its RHEL 7 hosts' license. Yum updating should work the same way it works on the host, but I have not been able to play with RHEL 7 yet (blame my SysAdmins).

Useful scripts

build.sh : builds the image locally (docker build)
runbash.sh : convenient way to run commands on a new container (fast-food, auto-destroy) or even to just open a bash shell to play.

Some nice tests:

Show CentOS version:

./runbash.sh cat /etc/redhat=release
CentOS Linux release 7.0.1406 (Core)

Show files (ls):

./runbash.sh ls -l /opt/
total 0

Using a local mirror (OPTIONAL)

If you plan to build a lot of images locally it may be a good idea to setup a local mirror of a CentOS yum repository (by "local" I mean somewhere in your LAN). This is not a complicated task, but it takes some disk space and bandwidth (at least on the first rsync).

Take your time, have some patience until you get the proper rsync command that works with the mirror you are rsyncing from (make sure you are syncing only x86_64 packages, for example). After syncing you'll also want to serve these folders with a plain Apache - the URLs that point to your local mirror are the ones you will put into the custom repo file included in this project.

There is a line to uncomment at the Dockerfile that replaces the standard repo file for the custom one that should be edited in order to point to your local mirror.