Docker

Been playing a little with Docker↗ this afternoon, while its something I have been aware for a while its not something I have really looked into.

As I prefer working with CentOS rather than Ubuntu its taken me a while to get the motivation to do any more than some reading, however as the latest version now runs on RHE compatible

yum install http://www.mirrorservice.org/sites/dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
yum -y install docker-io
service docker start
chkconfig docker on

Once the services are installed pull down some images to test with;

docker pull ubuntu
docker pull centos
docker run centos /bin/echo hello world

the last command launches a CentOS container, runs the echo and then exits. To do something more interesting;

CONTAINER_ID=$(sudo docker run -d ubuntu /bin/sh -c “while true; do echo hello world; sleep 1; done”)
docker ps
docker attach -sig-proxy=false $CONTAINER_ID
docker logs $CONTAINER_ID
docker stop $CONTAINER_ID

Once you have some containers running the following commands are useful;

docker info # Get some information on the installation
docker images # List the available images
docker ps # Whats running?
docker search [TERM] # Search for images

This is probably one of the better introductions to Docker I have seen;

and some further reading;

• Simple SAAS↗
• List of projects↗
• Puppet Module↗