Reusable content

In Jekyll, reusable content is managed using include snippets, which are located in the /app/_includes folder. Use includes to reuse snippets of the same content across multiple pages.

The examples in this topic reference a short include file with a snippet about installation.

Snippets from that include file are called with an include tag in a few target files, such as the Docker installation guide.

Create an include

File formats and directories

Add a Markdown (.md) or HTML (.html) file to the /app/_includes directory at the root of the Kong/docs.konghq.com repository.

Markdown includes contain snippets of documentation content, for example, common installation steps.
HTML includes contain pieces of website layout and functionality, for example, the footer and top navigation bar.

If your Markdown include does not need to belong to a particular product version, place it in a product directory. For example:

app/_includes/mesh
app/_includes/plugins-hub

If the include will be used across products, place it directly in of the app/_includes/md/ directory.

If you have different versions of the include content:

Content for current version continues to live at the root of the product directory

Versioned content (for non-current versions only!) lives in a sub-directory named {VERSION_NUMBER}

Markdown comments

At the top of an include file, add a Markdown comment to note the instances where this include is being used. For example:

<!-- Shared between all Community Linux installation topics: Amazon Linux,
 CentOS, Debian, RedHat, and Ubuntu -->

Page variables

If using page variables inside an include, replace page in the variable with include. For example, page.kong_version becomes include.kong_version.

This is an include that uses {{ include.kong_version }}.

This is necessary because we use the jekyll_include_cache plugin on the docs site, and the plugin needs to know that the variable should not be cached.

Use an include

To add an include, use the include tag with the following basic syntax:

{% include_cached /md/install.md %}

Declare the tag with include_cached
Add a path relative to the _includes directory

Depending on the content of the snippet, you can pass various parameters to the include tag. If the include content has a variable anywhere in the text, map it to the page variable:

{% include_cached /md/install.md kong_version=page.kong_version %}

This maps page.kong_version to the include.kong_version from the source include file.

Conditional content

You can add if statements to an include to create variations of the content for use in different contexts. For example, in an file named install.md, you might have a snippet where the instructions are specific to Docker:

{% if include.install == "docker" %}
your docker content goes here
{% endif %}

In the target file (the file where you want the content to display), call the Docker section of the include:

{% include_cached /md/install.md install='docker' %}

The syntax for the if statement and the include is not the same.

When creating an if statement condition based on a string, the string must be enclosed in double quotes (" ") and use two equals signs: if include.install == "docker"

When calling the section in an include_cached tag, use single quotes (' ') and one equals sign: install='docker'

include-check script

The Kong docs site runs an include check script on every change pushed to the repository. If you run into issues with an include, the check will flag them. See more info about the include check in our repository README.