Docker 0.11 is the Release Candidate for 1.0

One of the most-asked questions we’ve been hearing these last couple months is, “When is 1.0 coming?”  While not a direct answer, today we’re pleased to announce the immediate availability of Docker 0.11 – the first Release Candidate (RC) for 1.0.  From here, we want to continue to get your feedback, focus on quality.

RC designation aside, there are a lot of features to be excited about in this release.  Here are the big ones:

• SELinux support.  Big shout-out to community member Dan Walsh, “Mr. SELinux” of Red Hat fame, for the work he contributed on this. To run the daemon with SELinux support, use docker -d --selinux-enabled

• Host networking.  For those wanting their containers to directly access the host system’s network interfaces, Docker 0.11 features a “host networking” mode. A container in host networking mode is sandboxed as usual, except for its network stack which is shared with the host system.

  By default, when you start a container, it’ll only have a loopback interface lo and a virtual interface eth1 conected to the docker bridge:

  $> docker run busybox ip a

  1	$> docker run busybox ip a

  You can now directly use the interfaces of you host (it’s much faster as it doesn’t go through the bridge) via --net=host:

  $> docker run --net=host busybox ip a

  1	$> docker run --net=host busybox ip a

• Link hostnames. When containers are linked together, they can now discover each other by hostname. For example your application frontend could connect to its database by simply opening a connection to the hostname “db”. This discovery method is optional, you can still use the usual environment variable discovery method.You can start a redis server on you machine, giving it the name ‘redis’ with:

  $> docker run -d --name redis crosbymichael/redis a6011908ba

  1 2	$> docker run -d --name redis crosbymichael/redis a6011908ba

  and if you start a redis-cli container with the redis container linked into it, you can use:

  $> docker run -it --name redis-cli --link redis:redis crosbymichael/redis-cli -h redis

  1	$> docker run -it --name redis-cli --link redis:redis crosbymichael/redis-cli -h redis

  as the redis-cli container will have it’s /etc/hosts populated the redis container ip.

• Ping Docker daemon.  We’ve added an endpoint that’ll allow you to ping the Docker daemon to see if it’s alive for things like health checks.

• Timestamps.  With Docker 0.11, there are now timestamps in all the logs provided by the daemon for each container. See docker logs -t

• Access registry mirrors with multiple endpoints.  This feature in the header of Docker calls allows for chaining of multiple registry mirrors, eg, if one mirror has an outage, re-direct to the standby mirror, etc.

• SHA-512.  Adding SHA-512 enables support for certain SSL certificates.

The above major features plus bug fixes total 266 merged pull requests in Docker 0.11 – check out the full list.  Big thanks and shout-out to all contributors, particularly Dan Walsh, Victor Marmol, and Rohit Jnagal!

As we head into the home stretch toward 1.0, we look forward to your feedback and input!

Dockerize early and often,

- The Docker Team

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• Getting to Docker 1.0