mike

mike

mike is a Python utility that makes it easy to deploy multiple versions of your MkDocs-powered docs to a Git branch, suitable for hosting on Github via gh-pages. To see an example of this in action, take a look at the documentation for bfg9000.

Why Use mike?

mike is built around the idea that once you've generated your docs for a particular version, you should never need to touch that version again. This means you never have to worry about breaking changes in MkDocs, since your old docs (built with an old version of MkDocs) are already generated and sitting in your gh-pages branch.

While mike is flexible, it's optimized around putting your docs in a <major>.<minor> directory, with optional aliases (e.g. latest or dev) to particularly notable versions. This makes it easy to make permalinks to whatever version of the documentation you want to direct people to.

How It Works

mike works by creating a new Git commit on your gh-pages branch every time you deploy a new version of your docs using mike deploy (or other mike subcommands that change your gh-pages branch). When deploying a particular version, previously-deployed docs for that version are erased and overwritten, but docs for other versions remain untouched.

Installation

Like most Python projects, mike uses setuptools, so installation is what you might expect:

pip install mike

Once you've installed mike, you might also want to set up shell-completion for it. If you have shtab installed, you can do this with mike generate-completion, which will print the shell-completion code for your shell. For more details on how to set this up, consult shtab's documentation.

Usage

Before Using mike

Before using mike for the first time, you may want to use mike delete --all to delete any old documentation on your gh-pages branch before building your new versioned docs. (If you prefer, you can also manually move your old documentation to a subdirectory of your gh-pages branch so that it's still accessible.)

Configuration

To help integrate into the MkDocs build process, mike uses an MkDocs plugin. This plugin is added by default when building your documentation with mike, but by adding it explicitly to your mkdocs.yml file, you can configure how the plugin works. The plugin adds a version selector to supported themes as well as updating the site_url (if you set it) to point to the version of the docs that are being built:

plugins:
  - mike:
      # These fields are all optional; the defaults are as below...
      alias_type: symlink
      redirect_template: null
      deploy_prefix: ''
      canonical_version: null
      version_selector: true
      css_dir: css
      javascript_dir: js

• alias_type: The method to create aliases; one of:
  • symlink: Create a symbolic link from the alias to the base directory of the documentation
  • redirect: Create an HTML redirect for each page of the documentation
  • copy: Copy all the files of the documentation to the alias's path
• redirect_template: The template file to use when creating HTML redirects; if null, use the default template
• deploy_prefix: The root directory to put the generated docs in; this can be useful if you'd like to have other pages at the root of your site, or to host multiple, independently-versioned sets of docs side by side
• canonical_version: The "canonical" version to use for the documentation, useful for telling search engines what pages to prefer (e.g. latest if you've defined that as an alias that always points to the latest release); if null, mike will use the version specified via mike deploy
• version_selector: True if the version selector should be shown on pages; false otherwise
• css_dir: The directory to place the version selector's CSS
• javascript_dir: The directory to place the version selector's Javascript

Building Your Docs

mike is designed to produce one version of your docs at a time. That way, you can easily deploy a new version without touching any older versions of your docs; this can be especially important if your old docs are no longer buildable with the newest version of MkDocs (or if they weren't built with MkDocs at all!). To deploy the current version of your docs, simply run:

mike deploy [version]

Where [version] is the current version of your project, represented however you like (I recommend using [major].[minor] and excluding the patch number). You can also pass aliases to the deploy command to host a particularly-relevant version of your docs somewhere special (e.g. latest):

mike deploy [version] [alias]...

If [version] already exists, this command will also update all of the pre-existing aliases for it. Normally, if an alias specified on the command line is already associated with another version, this will return an error. If you do want to move an alias from another version to this version (including when the new version itself was previously an alias), you can pass -u/--update-aliases to allow this. For example, this can be useful when releasing a new version and updating the latest alias to point to this new version.

By default, each alias creates a symbolic link to the base directory of the real version of the docs; to create a copy of the docs for each alias, you can pass --alias-type=copy, or to use a simple HTML redirect for each page, you can pass --alias-type=redirect. If you're using redirects, you can customize the redirect template with -T/--template; this takes a path to a Jinja template that accepts an {{href}} variable.

If you'd like to specify a title for this version that doesn't match the version string, you can pass -t TITLE/--title=TITLE as well. You can set custom properties for this version as well, using --prop-set, --prop-set-string, --prop-set-all, --prop-delete, and --prop-delete-all (see the Managing Properties section for more details).

In addition, you can specify where to deploy your docs via -b/--branch, -r/--remote, and --deploy-prefix, specifying the branch, remote, and directory prefix within the branch, respectively. Finally, to push your docs to a remote branch, simply add -p/--push to your command.

You can also specify many of these options via your mkdocs.yml configuration as shown above. For example, --alias-type can also be specified via plugins.mike.alias_type. (For --branch and --remote, you can use the built-in MkDocs fields remote_branch and remote_name.)

Viewing Your Docs

When editing your documentation, you can usually just use the ordinary mkdocs serve to show the genereated results. This serves the current version of your documentation without forcing you to create a Git commit first via mike deploy.

If you want to test all the versions of your documentation as you'd see on your production server, you can serve them locally via:

mike serve

This serves your current documentation as committed to your gh-pages branch. By default, it serves the docs at http://localhost:8000, but you can change this with -a/--dev-addr.

[!CAUTION] mike serve and mkdocs serve should be used for testing only. To host your docs for real, use a real web server.

Deleting Docs

Sometimes you need to delete an old version of your docs, either because you made a mistake or you're pruning unsupported versions. You can do this via the delete subcommand:

mike delete [identifier]...

If identifier is a version, this will delete the version and all its aliases from the branch; if it's an alias, it will only delete that alias.

If you'd like to completely wipe the contents of your docs branch, just run mike delete --all. Like deploy above, you can specify --branch, --push, etc to control how the commit is handled.

Listing Docs

If you ever need to see the list of all currently-deployed doc versions, you can run:

mike list

To list the info for a particular version, you can just pass the version name or an alias to that version:

mike list [identifier]

Sometimes, you need this information to be consumed by another tool. In that case, pass -j/--json to return the list of doc versions as JSON.

Setting the Default Version

With all the versions of docs you have, you may want to set a default version so that people going to the root of your site are redirected to the latest version of the docs:

mike set-default [identifier]

Normally, this command will return an error if identifier doesn't exist. If you want to set the default to a version that doesn't exist yet, you can pass --allow-undefined.

If you want to use a different template from the default, you can pass -T/--template; this takes a path to a Jinja template that accepts an {{href}} variable. (Note that this page always uses a redirect, no matter the setting of alias_type/--alias-type.)

Like deploy and delete above, you can specify --branch, --push, etc to control how the commit is handled.

Changing a Version's Title

As you update your docs, you may want to change the title of a particular version. For example, your 1.0 docs might have the title 1.0.0, and when you release a new patch, you want to update the title to 1.0.1. You can do this with the retitle command:

mike retitle [identifier] [title]

As with other commands that change your docs, you can specify --branch, --push, etc to control how the commit is handled.

Adding a New Version Alias

Sometimes, you might need to add a new alias for a version without rebuilding your documentation. You can use the alias command for this:

mike alias [identifier] [alias]...

As with deploy, you can pass -u/--update-aliases to change where an existing alias points to.

Once again, you can specify --branch, --push, etc to control how the commit is handled.

Managing Properties

Each version of your documentation can have any arbitrary properties assigned to it that you like. You can use these properties to hold extra metadata, and then your documentation theme can consult those properties to do whatever you like. When using the built-in MkDocs themes, mike supports one property: hidden. When this is true, that version will be hidden from the version selector (unless it's the current version).

You can get properties via props command:

mike props [identifier] [prop]

If prop is specified, this will return the value of that property; otherwise, it will return all of that version's properties as a JSON object.

You can also set properties by specifying one or more of --set prop=json, --set-string prop=str, --set-all json, --delete prop, and --delete-all. (If you prefer, you can also set properties at the same time as deploying via the --prop-* options.)

When getting or setting a particular property, you can specify it with a limited JSONPath-like syntax. You can use bare field names, quoted field names, and indices/field names inside square brackets. The only operator supported is .. For example, this is a valid expression:

foo."bar"[0]["baz"]

When setting values, you can add to the head or tail of a list via the head or tail keywords, e.g.:

foo[head]

As usual, you can specify --branch, --push, etc to control how the commit is handled.

More Details

For more details on the available options, consult the --help command for mike.

Version Ordering

There are lots of versioning schemes out there, but mike tries its best to order your versions in a reasonable manner. Version identifiers that "look like" versions (e.g. 1.2.3, 1.0b1, v1.0) are treated as ordinary versions, whereas other identifiers, like devel, are treated as development versions, and placed above ordinary versions.

The above scheme should get things right most of the time, but you can always post-process your versions.json file to manipulate the ordering to suit your needs.

Staying in Sync

mike will do its best to stay in-sync with your remote repository and will automatically update your local branch to match the remote's if possible (note that mike won't automatically git fetch anything). If your local branch has diverged from your remote, mike will leave it as-is and ask you what to do. To ignore the remote's state, just pass --ignore-remote-status.

CNAME (and Other Special Files)

Some special files that you'd like to deploy along with your documentation (such as CNAME) aren't related to a particular version of the docs, and instead need to go in the root directory of your site. There's no special handling for this in mike, but since your built docs live on a Git branch, it's still easy to manage: check out your gh-pages branch (or wherever your built docs live), and commit the necessary files to the root directory.

Deploying via CI

Since mike just generates commits to an ordinary Git branch, it should work smoothly with your favorite CI system. However, you should keep in mind that some CI systems make shallow clones of your repository, meaning that the CI job won't have a local instance of your documentation branch to commit to. This will naturally cause issues when trying to push the commit. This is easy to resolve though; just manually fetch your gh-pages branch (or whichever you deploy to) before running mike:

git fetch origin gh-pages --depth=1

You may also need to configure a Git user so that mike can make commits:

git config user.name ci-bot
git config user.email [e-mail]

Alternately, you can set the environment variables GIT_COMMITTER_NAME and GIT_COMMITTER_EMAIL (as well as GIT_COMMITTER_DATE if you like):

GIT_COMMITTER_NAME=ci-bot GIT_COMMITTER_EMAIL=[e-mail] \
mike deploy 1.0

For Theme Authors

If you'd like to provide support for mike in your theme, you just need to fetch versions.json and build a version selector. versions.json looks like this:

[
  {"version": "1.0", "title": "1.0.1", "aliases": ["latest"]},
  {"version": "0.9", "title": "0.9", "aliases": [], "properties": "anything"}
]

Every version has a version string, a title (which may be the same as version), a list of aliases, and optionally, a properties attribute that can hold anything at all. These properties can be used by other packages, themes, etc in order to add their own custom metadata to each version.

If you're creating a third-party extension to an existing theme, you add a setuptools entry point for mike.themes pointing to a Python submodule that contains css/ and js/ subdirectories containing the extra code to be installed into the user's documentation. This will then automatically be included via the mike plugin in the user's mkdocs.yml file.

To see some examples of how to work with this, check the mike/themes/mkdocs directory.

License

This project is licensed under the BSD 3-clause license.