Continuous integration/Documentation generation

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Documentation is automatically generated and published to For increased flexibility and security, the static sites are generated inside WMCS instances. The docs then fetched from the instance to the CI production host and then pushed with rsync to the documentation host (doc1001.eqiad.wmnet since January 9th 2019). This page documents the workflow, part of the technical implementation, and how to define a new job.


Our Zuul layout reacts on two kinds of Gerrit events which are matched by two different pipelines:

Gerrit event Zuul pipeline Description
change-merged postmerge When a change is merged by Gerrit
ref-updated publish A reference is changed (tip of branch changes, tags modifications)

ref-updated could cover the changes being merged, but the event is not associated with a Gerrit change number which prevents us from reporting back to the Gerrit interface. We thus use postmerge to report back in Gerrit so the user knows the documentation has been generated and the publish pipeline which handles references updates matching ^refs/tags/.

In both case (change-merged or ref-updated) we trigger the same job to generate the documentation for any branch or tag. We thus need to namespace the documentation under based on the branch name or the tag name. The information is carried differently between events and the reference is slightly different between branch updates and tags. The conversion logic is carried by a Zuul python function which is associated to all the publish jobs. It injects to the Gearman function (and thus the Jenkins job environment) a variable DOC_SUBPATH which represents the version. Example:

  • change merged on REL1_24 branch: DOC_SUBPATH = REL1_24
  • refs/tags/1.24.0 updated: DOC_SUBPATH = 1.24.0

Reference: Gerrit change 173049

We can thus reuse that DOC_SUBPATH parameter to easily namespace the jobs per versions. As an example has documentation for both release branches and tags.

Jenkins job builder definitions[edit]

Most of the logic is defined in Jenkins Job Builder jjb/publish.yaml configuration file.

In a job definition, a builder defines what steps to execute. We provide a builder macro called doc-publish that takes care of transferring the generated files to the web server of It takes two parameters:

  1. docsrc Directory holding documentation files relative to workspace (without trailing slash)
  2. docdest Directory under

Example job definition:

# Typical PHP project
- job-template:
  name: myproject-publish
   - doxygen
   - doc-publish:
      docsrc: 'doc/html'
      docdest: myproject

# Typical JS project
- job-template:
  name: myproject-publish
   - jsduck
   - doc-publish:
      docsrc: 'docs'
      docdest: myproject

This will invoke the build scripts (doxygen and jsduck) and publish their results (respectively in doc/html and docs) to

To namespace the documentation based on project version, use the Zuul-generated DOC_SUBPATH (derived from branch or tag name). Simply insert it in the docdest parameter. You will need to invoke the builder assert-env-doc_subpath. Example for MediaWiki (mediawiki-core-doxygen-publish job):

- job:
    name: 'mediawiki-core-doxygen-publish'
     - assert-env-doc_subpath
     - zuul-cloner:
         projects: >
     # Build the documentation under /build/doc
     - shell: |
         rm -rf build/doc
         mkdir -p build/doc
         TARGET_BASEDIR="$WORKSPACE/build/doc" /srv/deployment/integration/slave-scripts/tools/
     # Publish from build/doc to mediawiki-core/$DOC_SUBPATH/php'
     - doc-publish:
         docsrc: 'build/doc'
         docdest: 'mediawiki-core/$DOC_SUBPATH/php'

This publishes the documentation at, and also publishes release branch documentation such as, and tagged releases such as


The documentations are ultimately published on which is a production machine (doc1001.eqiad.wmnet since January 2019). They are generated on WMCS instance part of the integration Toolforge project which are not allowed to communicate with production machines.

A job publish-to-doc1001 executes on the CI Jenkins production node which fetches artifacts from the build workspace using rsync + ssh. The content is then rsynced to doc1001.eqiad.wmnet (rsync://doc1001.eqiad.wmnet/doc/).

Updating the site[edit]

The configuration is done with Puppet by profile::doc

The "static" content of the site is in the git repository integration/docroot. Most of the pages use light PHP to show a table of content, include a footer, etc.

The git docroot is deployed to the doc host(s) using scap:

 ssh deployment.eqiad.wmnet
 cd /srv/deployment/integration/docroot
 git fetch origin
 # review the diff
 git rebase

See also[edit]

  • Continuous integration/Entry points describes the conventions for extension automation. If you follow these when developing your extension, then (with a lot of CI wizardry), tests run and documentation generates "automagically".