Download Docker 1.3

Docker is an open source developer tool that can be used to create installation packages. It puts the application including all the components it depends on in a virtual container that can run on almost any Linux machine. This should simplify development and installation for the various Linux distributions. This week, version 1.3 of Docker was released and its release notes can be found below.

Version 1.3.0

This version fixes a number of bugs and issues and adds new functions and other improvements. These include:

New command: docker exec

The new docker exec command lets you run a process in an existing, active container. The command has APIs for both the daemon and the client. With docker exec, you’ll be able to do things like add or remove devices from running containers, debug running containers, and run commands that are not part of the container’s static specification.

New command: docker create

Traditionally, the docker run command has been used to both create a container and spawn a process to run it. The new docker create command breaks this separately, letting you set up a container without actually starting it. This provides more control over management of the container lifecycle, giving you the ability to configure things like volumes or port mappings before the container is started. For example, in a rapid-response scaling situation, you could use create to prepare and stage ten containers in anticipation of heavy loads.

New provenance features

Official images are now signed by Docker, Inc. to improve your confidence and security. Look for the blue ribbons on the Docker Hub. The Docker Engine has been updated to automatically verify that a given Official Repo has a current, valid signature. If no valid signature is detected, Docker Engine will use a prior image.

Other improvements & changes

We’ve added a new security options flag that lets you set SELinux and AppArmor labels and profiles. This means you’ll longer have to use `docker run –privileged on kernels that support SE Linux or AppArmor.