Docker Documentation

Overview

The source for Docker documentation is here under sources/ in the form of .rst files. These files use reStructuredText formatting with Sphinx extensions for structure, cross-linking and indexing.

The HTML files are built and hosted on readthedocs.org, appearing via proxy on https://docs.docker.io. The HTML files update automatically after each change to the master or release branch of the docker files on GitHub thanks to post-commit hooks. The "release" branch maps to the "latest" documentation and the "master" branch maps to the "master" documentation.

Branches

There are two branches related to editing docs: master and a doc* branch (currently doc0.8.1). You should normally edit docs on the master branch. That way your fixes will automatically get included in later releases, and docs maintainers can easily cherry-pick your changes to bring over to the current docs branch. In the rare case where your change is not forward-compatible, then you could base your change on the appropriate doc* branch.

Now that we have a doc* branch, we can keep the latest docs up to date with any bugs found between docker code releases.

Warning: When reading the docs, the master documentation may include features not yet part of any official docker release. Master docs should be used only for understanding bleeding-edge development and latest (which points to the doc* branch``) should be used for the latest official release.

If you need to manually trigger a build of an existing branch, then you can do that through the readthedocs interface. If you would like to add new build targets, including new branches or tags, then you must contact one of the existing maintainers and get your readthedocs.org account added to the maintainers list, or just file an issue on GitHub describing the branch/tag and why it needs to be added to the docs, and one of the maintainers will add it for you.

Getting Started

To edit and test the docs, you'll need to install the Sphinx tool and its dependencies. There are two main ways to install this tool:

Native Installation

Install dependencies from requirements.txt file in your docker/docs directory:

• Linux: pip install -r docs/requirements.txt

• Mac OS X: [sudo] pip-2.7 install -r docs/requirements.txt

Alternative Installation: Docker Container

If you're running docker on your development machine then you may find it easier and cleaner to use the docs Dockerfile. This installs Sphinx in a container, adds the local docs/ directory and builds the HTML docs inside the container, even starting a simple HTTP server on port 8000 so that you can connect and see your changes.

In the docker source directory, run: make docs

This is the equivalent to make clean server since each container starts clean.

Contributing

Normal Case:

• Follow the contribution guidelines (see ../CONTRIBUTING.md).
• Remember to sign your work!
• Work in your own fork of the code, we accept pull requests.
• Change the .rst files with your favorite editor -- try to keep the lines short and respect RST and Sphinx conventions.
• Run make clean docs to clean up old files and generate new ones, or just make docs to update after small changes.
• Your static website can now be found in the _build directory.
• To preview what you have generated run make server and open http://localhost:8000/ in your favorite browser.

make clean docs must complete without any warnings or errors.

Special Case for RST Newbies:

If you want to write a new doc or make substantial changes to an existing doc, but you don't know RST syntax, we will accept pull requests in Markdown and plain text formats. We really want to encourage people to share their knowledge and don't want the markup syntax to be the obstacle. So when you make the Pull Request, please note in your comment that you need RST markup assistance, and we'll make the changes for you, and then we will make a pull request to your pull request so that you can get all the changes and learn about the markup. You still need to follow the CONTRIBUTING guidelines, so please sign your commits.

Working using GitHub's file editor

Alternatively, for small changes and typos you might want to use GitHub's built in file editor. It allows you to preview your changes right online (though there can be some differences between GitHub markdown and Sphinx RST). Just be careful not to create many commits. And you must still sign your work!

Images

When you need to add images, try to make them as small as possible (e.g. as gif). Usually images should go in the same directory as the .rst file which references them, or in a subdirectory if one already exists.

Notes

• For the template the css is compiled from less. When changes are needed they can be compiled using

  lessc lessc main.less or watched using watch-lessc watch-lessc -i main.less -o main.css

Guides on using sphinx

• To make links to certain sections create a link target like so:

    .. _hello_world:
  
    Hello world
    ===========
  
    This is a reference to :ref:`hello_world` and will work even if we
    move the target to another file or change the title of the section. 
  

  The _hello_world: will make it possible to link to this position (page and section heading) from all other pages. See the Sphinx docs for more information and examples.

• Notes, warnings and alarms

    # a note (use when something is important)
    .. note::
  
    # a warning (orange)
    .. warning::
  
    # danger (red, use sparsely)
    .. danger::
  
  

• Code examples

  • Start typed commands with $ (dollar space) so that they are easily differentiated from program output.
  • Use "sudo" with docker to ensure that your command is runnable even if they haven't used the docker group.

Manpages

• To make the manpages, run make man. Please note there is a bug in Sphinx 1.1.3 which makes this fail. Upgrade to the latest version of Sphinx.
• Then preview the manpage by running man _build/man/docker.1, where _build/man/docker.1 is the path to the generated manfile