Download Docker 1.5

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 1.5 of Docker was released and its release notes can be found below.

Docker 1.5: IPv6 support, read-only containers, stats, “named Dockerfiles” and more

The Docker project team wanted to start the new year out right with something awesome; that’s why we’re super excited to announce the first docker release for 2015. We’ve smashed many long-standing, annoying bugs and merged a few awesome features that both the community and maintainers are excited about. Let’s check out what’s in Docker 1.5.

IPv6 support
You can now allocate an ipv6 address to each container with the new ‘–ipv6’ flag. You can resolve ipv6 addresses from within a container. You can even use this feature to have containers communicate across multiple hosts. For more information on setting up ipv6 and how it works, check out thedocs†

Read only containers
You can now enable a read-only filesystem for your container via the –read-only flag. The read-only feature allows you to restrict the locations that an application inside a container can write files to. By using this capability in combination with volumes, you can make sure containers only persist data where it can be managed in a known location.

stats
Containers are cool. They allow you to package and run your applications in a portable way and let you set resource constraints on your applications to make sure that no one application can take over an entire machine. In order to choose accurate resource limits for your applications, profiling is required to collect this information.

In Docker 1.5, we introduce a new stats API endpoint and CLI command that will stream live CPU, memory, network IO and block IO for your containers. You can use the API endpoint to build tools that feed live resource information for your containers into your existing monitoring solutions, or build live dashboards directly using the API.

Specify the Dockerfile to use in build
This is possibly one of the most requested feature in the past few months: the ability to specify the file to use in a docker build rather than relying on the default Dockerfile. docker build -f allows you to define multiple Dockerfiles in a single project and specify which one to use at build time. This can be helpful if you require separate Dockerfiles for testing and production environments.

Open Image Spec
As we continue to grow the contributor community to the Docker project, we wanted to encourage more work in the area around how Docker constructs images and their layers. As a start, we have documented how Docker currently builds and formats images and their configuration. Our hope is that these details allow contributors to better understand this critical facet of Docker as well as help contribute to future efforts to improve the image format. the v1 image specification can be found here†