Hosting Documentation

After going through the Package Guide and Doctests page you will need to host the generated documentation somewhere for potential users to read. This guide will describe how to setup automatic updates for your package docs using the Travis build service and GitHub Pages. This is the same approach used by this package to host its own docs – the docs you're currently reading.

Overview

Once setup correctly the following will happen each time you push new updates to your package repository:

• travis buildbots startup and run your tests;

• each buildbot will build the package docs using your docs/make.jl script;

• a single buildbot will then try to push the generated docs back to GitHub.

Note that the hosted documentation does not update when you make pull requests; you see updates only when you merge to master or push new tags.

The following sections outline how to enable this for your own package.

SSH Deploy Keys

Deploy keys provide push access to a single repository, to allow secure deployment of generated documentation from Travis to GitHub.

Open a Julia REPL and import Documenter.

julia> using Documenter

Then call the Travis.genkeys function as follows:

julia> Travis.genkeys("MyPackage")

where "MyPackage" is the name of the package you would like to create deploy keys for. The output will look similar to the text below:

INFO: add the public key below to https://github.com/USER/REPO/settings/keys
      with read/write access:

[SSH PUBLIC KEY HERE]

INFO: add a secure environment variable named 'DOCUMENTER_KEY' to
      https://travis-ci.org/USER/REPO/settings with value:

[LONG BASE64 ENCODED PRIVATE KEY]

Follow the instructions that are printed out, namely:

1. Add the public ssh key to your settings page for the GitHub repository that you are setting up by following the .../settings/key link provided. Click on Add deploy key, enter the name documenter as the title, and copy the public key into the Key field. Note that you should include no whitespace when copying the key. Check Allow write access to allow Documenter to commit the generated documentation to the repo.

2. Next add the long private key to the Travis settings page using the provided link. Again note that you should include no whitespace when copying the key. In the Environment Variables section add a key with the name DOCUMENTER_KEY and the value that was printed out. Do not set the variable to be displayed in the build log. Then click Add.

   Security warning

   To reiterate: make sure that the "Display value in build log" option is OFF for the variable, so that it does not get printed when the tests run. This base64-encoded string contains the unencrypted private key that gives full write access to your repository, so it must be kept safe. Also, make sure that you never expose this variable in your tests, nor merge any code that does. You can read more about Travis environment variables in Travis User Documentation.

.travis.yml Configuration

In the after_success section of the .travis.yml file, where code coverage is processed, run your docs/make.jl file:

after_success:
  - julia -e 'Pkg.add("Documenter")'
  - julia -e 'cd(Pkg.dir("PACKAGE_NAME")); include(joinpath("docs", "make.jl"))'

The deploydocs Function

At the moment your docs/make.jl file probably only contains

using Documenter, PACKAGE_NAME

makedocs()

We'll need to add an additional call to this file after makedocs. Add the following at the end of the file:

deploydocs(
    repo = "github.com/USER_NAME/PACKAGE_NAME.jl.git"
)

where USER_NAME and PACKAGE_NAME must be set to the appropriate names. Note that repo should not specify any protocol, i.e. it should not begin with https:// or git@.

By default deploydocs will deploy the documentation from the nightly Julia build for Linux. This can be changed using the julia and osname keywords as follows:

deploydocs(
    deps   = Deps.pip("mkdocs", "python-markdown-math"),
    repo   = "github.com/USER_NAME/PACKAGE_NAME.jl.git",
    julia  = "0.4",
    osname = "osx"
)

This will deploy the docs from the OSX Julia 0.4 Travis build bot.

The keyword deps serves to provide the required dependencies to deploy the documentation. In the example above we include the dependencies mkdocs and python-markdown-math. The former makes sure that MkDocs is installed to deploy the documentation, and the latter provides the mdx_math markdown extension to exploit MathJax rendering of latex equations in markdown. Other dependencies should be included here.

See the deploydocs function documentation for more details.

The MkDocs mkdocs.yml File

We'll be using MkDocs to convert the markdown files generated by Documenter to HTML. (This, of course, is not the only option you have for this step. Any markdown to HTML converter should work fine with some amount of setting up.)

Add an mkdocs.yml file to your docs/ directory with the following content:

site_name:        PACKAGE_NAME.jl
repo_url:         https://github.com/USER_NAME/PACKAGE_NAME.jl
site_description: Description...
site_author:      USER_NAME

theme: readthedocs

extra_css:
  - assets/Documenter.css

extra_javascript:
  - https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS_HTML
  - assets/mathjaxhelper.js

markdown_extensions:
  - extra
  - tables
  - fenced_code
  - mdx_math

docs_dir: 'build'

pages:
  - Home: index.md

This is only a basic skeleton. Read through the MkDocs documentation if you would like to know more about the available settings.

.gitignore

Add the following to your package's .gitignore file

docs/build/
docs/site/

These are needed to avoid committing generated content to your repository.

gh-pages Branch

By default, Documenter pushes documentation to the gh-pages branch. If the branch does not exist it will be created automatically by deploydocs. If does exist then Documenter simply adds an additional commit with the built documentation. You should be aware that Documenter may overwrite existing content without warning.

If you wish to create the gh-pages branch manually the that can be done following these instructions.

Documentation Versions

When documentation is generated it is stored in one of the following folders:

• latest stores the most recent documentation that is committed to the master branch.

• stable stores the most recent documentation from a tagged commit. Older tagged versions are stored in directories named after their tags. These tagged directories are persistent and must be manually removed from the gh-pages branch if necessary.

Unless a custom domain is being used, the stable and latest pages are found at:

https://USER_NAME.github.io/PACKAGE_NAME.jl/stable
https://USER_NAME.github.io/PACKAGE_NAME.jl/latest

Once your documentation has been pushed to the gh-pages branch you should add links to your README.md pointing to the stable and latest documentation URLs. It is common practice to make use of "badges" similar to those used for Travis and AppVeyor build statuses or code coverage. Adding the following to your package README.md should be all that is necessary:

[![](https://img.shields.io/badge/docs-stable-blue.svg)](https://USER_NAME.github.io/PACKAGE_NAME.jl/stable)
[![](https://img.shields.io/badge/docs-latest-blue.svg)](https://USER_NAME.github.io/PACKAGE_NAME.jl/latest)

PACKAGE_NAME and USER_NAME should be replaced with their appropriate values. The colour and text of the image can be changed by altering docs-stable-blue as described on shields.io, though it is recommended that package authors follow this standard to make it easier for potential users to find documentation links across multiple package README files.

Final Remarks

That should be all that is needed to enable automatic documentation building. Pushing new commits to your master branch should trigger doc builds. Note that other branches do not trigger these builds and neither do pull requests by potential contributors.

If you would like to see a more complete example of how this process is setup then take a look at this package's repository for some inspiration.