Writing documentation

New documentation is always welcome!

Start by cloning the documentation repository:

git clone \
    https://gitlab.com/cki-project/documentation \
    documentation
cd documentation

The documentation uses Hugo with the Docsy theme to build the site, imported using Hugo Modules. All requirements can be installed via the system package manager, but we recommend, instead, to execute all of the commands in the shell of a container with everything preinstalled via make podman. In case you really want to install the dependencies, look for “dependencies for documentation” in the hugo-docs Dockerfile.

Add new documentation as markdown files inside the appropriate directory under content/. Every file should end in .md.

Documentation can be previewed by running make serve. A local web server will start and automatically refresh the preview each time a change is saved.

Check for syntax problems by running make lint. If you are dealing with URLs, check if any of them is broken with make link-check.

To submit changes, fork the repository, add the fork as a remote to the checkout and commit the changes. Push them to a new branch in the fork, and start a merge request against the parent.

Internal repository

The CKI documentation is open by default and maintained via the public repository. Additionally, an internal repository exists to be able to provide further confidential information.

The contents of these two repositories are used to generate two different versions of the documentation:

• the public documentation, solely based on information from the public repository
• the internal documentation, based on information from the public repository, supplemented by confidential details about internal infrastructure from the internal documentation repository. This is done using Hugo Modules to interleave files from the repositories, with files from the internal repository taking precedence. This allows the internal repository to add or overwrite files from the public repository.

The CKI deployment bot is configured to redeploy the internal documentation when changes to the public repository are merged.

To contribute to the internal repository, start by cloning the internal documentation repository next to the public repository and connect both checkouts with a symbolic link:

git clone \
    https://internal/documentation/repository.git \
    internal-documentation
cd internal-documentation
# Create relative symlink that works both inside `make podman` and outside.
ln -sn "../documentation" public-repo

The following step is running the prepare-public-repo.sh script, which will create symbolic links to linting scripts and settings that are defined in the public repo, but shared among the two documentations.

From this point you have access to every command under make mentioned before, and once again we recommend using a container to execute them.

Note that make serve will clean after itself, removing go.sum and restoring the production tag to public documentation reference in go.mod. That is an alternative to keep committing those files whenever changes to the public repository are merged.

Adding confidential information

With Hugo, content is organized into page bundles.

As an example, consider the following structure in the public repository:

documentation/content/
  \- _index.md
  \- page1.md
  \- page2/
     \- index.md

This will generate three pages: an index page for the top-level _index.md, and two content pages for page1.md and page2/index.md.

To include confidential content from additional Markdown files supplied via the internal repository:

1. In the public repository, move content Markdown files in branch bundles (directories with a _index.md file) into separate leaf bundles. In the example, this means moving page1.md into a separate directory:

   documentation/content/
     \- _index.md
     \- page1/
        \- index.md
     \- page2/
        \- index.md
   

2. In the internal repository, add the confidential content as a separate Markdown file in the appropriate page bundle:

   internal-documentation/content/
     \- page1/
        \- confidential-section.md
   

   This is what content/page1/confidential-section.md in the internal repository could look like:

   ---
   ---
   <!-- markdownlint-disable first-line-heading -->
   ## Confidential section
   
   Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
   tempor incididunt ut labore et dolore magna aliqua. ...
   

3. Reference the file via the include shortcode in content/page1/index.md in the public repository:

   ...
   {{% include "confidential-section.md" %}}
   ...
   

   When the public documentation is rendered, the missing include is ignored gracefully.