This README gives an overview of how to build and contribute to the documentation of Apache Flink.
The documentation is included with the source of Apache Flink in order to ensure that you always have docs corresponding to your checked out version. The online documentation at http://flink.apache.org/ is also generated from the files found here.
The dependencies are declared in the Gemfile in this directory. We use Markdown to write and Jekyll to translate the documentation to static HTML. All required dependencies are installed locally when you build the documentation through the build_docs.sh script. If you want to install the software manually, use Ruby's Bundler Gem to install all dependencies:
gem install bundler bundle install
Note that in Ubuntu based systems, it may be necessary to install the ruby-dev via apt to build native code.
The docs/build_docs.sh script installs dependencies locally, calls Jekyll, and generates the documentation in docs/content. You can then point your browser to docs/content/index.html and start reading.
If you call the script with the preview flag build_docs.sh -p, Jekyll will start a web server at localhost:4000 and watch the docs directory for updates. Use this mode to preview changes locally.
The documentation pages are written in Markdown. It is possible to use the GitHub flavored syntax and intermix plain html.
In addition to Markdown, every page contains a Jekyll front matter, which specifies the title of the page and the layout to use. The title is used as the top-level heading for the page.
--- title: "Title of the Page" ---
Furthermore, you can access variables found in docs/_config.yml as follows:
{{ site.NAME }}
This will be replaced with the value of the variable called NAME when generating the docs.
All documents are structed with headings. From these heading, a page outline is automatically generated for each page.
# Level-1 Heading <- Used for the title of the page ## Level-2 Heading <- Start with this one ### Level-3 heading #### Level-4 heading ##### Level-5 heading
Please stick to the “logical order” when using the headlines, e.g. start with level-2 headings and use level-3 headings for subsections, etc. Don‘t use a different ordering, because you don’t like how a headline looks.