About Docker CE

Estimated reading time: 7 minutes

Docker Community Edition (CE) is ideal for developers and small teams looking to get started with Docker and experimenting with container-based apps. Docker CE has three types of update channels, stable, test, and nightly:

  • Stable gives you latest releases for general availability.
  • Test gives pre-releases that are ready for testing before general availability.
  • Nightly gives you latest builds of work in progress for the next major release.

For more information about Docker CE, see Docker Community Edition.

Releases

For the Docker CE engine, the open repositories Docker Engine and Docker Client apply.

Releases of Docker Engine and Docker Client for general availability are versioned using dotted triples. The components of this triple are YY.mm.<patch> where the YY.mm component is referred to as the year-month release. The version numbering format is chosen to illustrate cadence and does not guarantee SemVer, but the desired date for general availability. The version number may have additional information, such as beta and release candidate qualifications. Such releases are considered “pre-releases”.

The cadence of the year-month releases is every 6 months starting with the 18.09 release. The patch releases for a year-month release take place as needed to address bug fixes during its support cycle.

Docker CE binaries for a release are available on download.docker.com as packages for the supported operating systems. Docker EE binaries are available on the Docker Store for the supported operating systems. The release channels are available for each of the year-month releases and allow users to “pin” on a year-month release of choice. The release channel also receives patch releases when they become available.

Nightly builds

Nightly builds are created once per day from the master branch. The version number for nightly builds take the format:

0.0.0-YYYYmmddHHMMSS-abcdefabcdef

where the time is the commit time in UTC and the final suffix is the prefix of the commit hash, for example 0.0.0-20180720214833-f61e0f7.

These builds allow for testing from the latest code on the master branch. No qualifications or guarantees are made for the nightly builds.

The release channel for these builds is called nightly.

Pre-releases

In preparation for a new year-month release, a branch is created from the master branch with format YY.mm when the milestones desired by Docker for the release have achieved feature-complete. Pre-releases such as betas and release candidates are conducted from their respective release branches. Patch releases and the corresponding pre-releases are performed from within the corresponding release branch.

While pre-releases are done to assist in the stabilization process, no guarantees are provided.

Binaries built for pre-releases are available in the test channel for the targeted year-month release using the naming format test-YY.mm, for example test-18.09.

General availability

Year-month releases are made from a release branch diverged from the master branch. The branch is created with format <year>.<month>, for example 18.09. The year-month name indicates the earliest possible calendar month to expect the release to be generally available. All further patch releases are performed from that branch. For example, once v18.09.0 is released, all subsequent patch releases are built from the 18.09 branch.

Binaries built from this releases are available in the stable channel stable-YY.mm, for example stable-18.09, as well as the corresponding test channel.

Relationship between CE and EE code

For a given year-month release, Docker releases both CE and EE variants concurrently. EE is a superset of the code delivered in CE. Docker maintains publicly visible repositories for the CE code as well as private repositories for the EE code. Automation (a bot) is used to keep the branches between CE and EE in sync so as features and fixes are merged on the various branches in the CE repositories (upstream), the corresponding EE repositories and branches are kept in sync (downstream). While Docker and its partners make every effort to minimize merge conflicts between CE and EE, occasionally they will happen, and Docker will work hard to resolve them in a timely fashion.

Next release

The activity for upcoming year-month releases is tracked in the milestones of the repository.

Support

Docker CE releases of a year-month branch are supported with patches as needed for 7 months after the first year-month general availability release. Docker EE releases are supported for 24 months after the first year-month general availability release.

This means bug reports and backports to release branches are assessed until the end-of-life date.

After the year-month branch has reached end-of-life, the branch may be deleted from the repository.

Reporting security issues

The Docker maintainers take security seriously. If you discover a security issue, please bring it to their attention right away!

Please DO NOT file a public issue; instead send your report privately to security@docker.com.

Security reports are greatly appreciated, and Docker will publicly thank you for it. Docker also likes to send gifts — if you’re into swag, make sure to let us know. Docker currently does not offer a paid security bounty program but are not ruling it out in the future.

Supported platforms

Docker CE is available on multiple platforms. Use the following tables to choose the best installation path for you.

Desktop

Platform x86_64
Docker for Mac (macOS) yes
Docker for Windows (Microsoft Windows 10) yes

Server

Platform x86_64 / amd64 ARM ARM64 / AARCH64 IBM Power (ppc64le) IBM Z (s390x)
CentOS yes   yes    
Debian yes yes yes    
Fedora yes        
Ubuntu yes yes yes yes yes

Backporting

Backports to the Docker products are prioritized by the Docker company. A Docker employee or repository maintainer will endeavour to ensure sensible bugfixes make it into active releases.

If there are important fixes that ought to be considered for backport to active release branches, be sure to highlight this in the PR description or by adding a comment to the PR.

Upgrade path

Patch releases are always backward compatible with its year-month version.

Not covered

As a general rule, anything not mentioned in this document may change in any release.

Exceptions

Exceptions are made in the interest of security patches. If a break in release procedure or product functionality is required, it will be communicated clearly, and the solution will be considered against total impact.

Get started

After setting up Docker, you can learn the basics with Getting started with Docker.

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