Content guidelines

Site content maintainability¶

The site has adopted Markdown as the standard way to create content for the site. Previously the site used an HTML based framework, which resulted in content not being frequently updated as there was a steep learning curve.

All content on the site should be created using Markdown. To ensure content is maintainable going forward only markdown features outlined below should be used to create site content. If you wish to use additional components on a page then please contact the documentation working group to discuss your requirements before creating a pull request containing additional components.

MkDocs includes the ability to create custom page templates. This facility has been used to create a customized home page for the site. If any other pages require a custom layout or custom features, then a page template should be used so the content can remain in Markdown. Creation of custom page templates should be discussed with the documentation working group.

Changing content¶

MkDocs supports standard Markdown syntax and a set Markdown extensions provided by plugins. The exact Markdown syntax supported is based on the python implementation.

MkDocs is configured using the mkdocs.yml file in the root of the git repository.

The mkdoc.yml file defines the top level navigation for the site. The level of indentation is configurable (this requires the theme to support this feature) with Markdown headings, levels 2 (##) and 3 (###) being used for the in-page navigation on the right of the page.

Standard Markdown features¶

The following markdown syntax is used within the documentation

HTML can be embedded in Markdown, but embedded HTML should not be used in the documentation. All content should use Markdown with the permitted extensions.

Indentation¶

MkDocs uses 4 spaces for tabs, so when indenting code ensure you are working with tabs set to 4 spaces rather than 2, which is commonly used.

When using some features of Markdown indentation is used to identify blocks.

1. Ubiquity EdgeRouter ER-X
    - runs DHCP (embedded), custom DNS server via AdGuard

    ![pic](./img/erx.jpg){width=80%}

In the code block above you will see the unordered list item is indented, so it aligns with the content of the ordered list (rather than aligning with the number of the ordered list). The image is also indented so it too aligns with the ordered list text.

Many of the Markdown elements can be nested and indentation is used to define the nesting relationship. If you look down on this page at the Information boxes section, the example shows an example of nesting elements and the Markdown tab shows how indentation is being used to identify the nesting relationships.

Links within MkDocs generated content¶

MkDocs will warn of any internal broken links, so it is important that links within the documentation are recognized as internal links.

• a link starting with a protocol name, such as http or https, is an external link
• a link starting with / is an external link. This is because MkDocs generated content can be embedded into another web application, so links can point outside of the MkDocs generated site but hosted on the same website
• a link starting with a file name (including the .md extension) or relative directory (../directory/filename.md) is an internal link and will be verified by MkDocs

As part of the build process a linkchecker application will check the generated html site for any broken links. You can run this linkchecker locally using the instructions. If any links in the documentation should be excluded from the link checker, such as links to localhost, then they should be added as a regex to the linkcheckerrc file, located in the root folder of the project - see linkchecker documentation for additional information

Markdown Extensions used in OKD.io¶

There are a number of Markdown extensions being used to create the site. See the mkdocs.yml file to see which extensions are configured. The documentation for the extensions can be found here

Link configuration¶

Links on the page or embedded images can be annotated to control the links and also the appearance of the links:

Image¶

Images are embedded in a page using the standard Markdown syntax ![description](URL), but the image can be formatted with Attribute Lists. This is most commonly used to scale an image or center an image, e.g.

![GitHub repo url](images/github-repo-url.png){style="width: 80%" .center }

External Links¶

External links can also use attribute lists to control behaviors, such as open in new tab or add a css class attribute to the generated HTML, such as external in the example below:

[MkDocs](http://mkdocs.org){: target="_blank" .external }

YouTube videos¶

It is not possible to embed a YouTube video and have it play in place using pure markdown. You can use HTML within the markdown file to embed a video:

<iframe width="100%" height="500" src="https://www.youtube.com/watch?v=qh1zYW7BLxE&t=431s" title="Building an OKD 4 Home Lab with special guest Craig Robinson" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Tabs¶

Content can be organized into a set of horizontal tabs.

=== "Tab 1"
    Hello

=== "Tab 2"
    World

produces :

Information boxes¶

The Admonition extension allows you to add themed information boxes using the !!! and ??? syntax:

!!! note
    This is a note

produces:

and

??? note
    This is a collapsible note

    You can add a `+` character to force the box to be initially open `???+`

produces a collapsible box:

You can override the title of the box by providing a title after the Admonition type.

!!!Example
    You can also nest different components as required

    === "note"
        !!!note
            This is a note

    === "collapsible note"
        ???+note
            This is a note

    === "custom title note"
        !!!note "Sample Title"
            This is a note

Supported Admonition Classes¶

The Admonitions supported by the Material theme are :

Code blocks¶

Code blocks allow you to insert code or blocks of text in line or as a block.

To use inline you simply enclose the text using a single back quote ` character. So a command can be included using `oc get pods` and will create oc get pods

When you want to include a block of code you use a fence, which is 3 back quote character at the start and end of the block. After the opening quotes you should also specify the content type contained in the block.

```shell
oc get pods
```

which will produce:

oc get pods

Notice that the block automatically gets the copy to clipboard link to allow easy copy and paste.

Every code block needs to identify the content. Where there is no content type, then text should be used to identify the content as plain text. Some of the common content types are shown in the table below. However, a full link of supported content types can be found here, where the short name in the documentation should be used.

Advanced highlighting of code blocks¶

There are some additional features available due to the highlight plugin installed in MkDocs. Full details can be found in the MkDocs Materials documentation.

Line numbers¶

You can add line numbers to a code block with the linenums directive. You must specify the starting line number, 1 in the example below:

``` javascript linenums="1"
<script>
document.getElementById("demo").innerHTML = "My First JavaScript";
</script>
```

creates

1
2
3

<script>
document.getElementById("demo").innerHTML = "My First JavaScript";
</script>

Spell checking¶

This project uses cSpell to check spelling within the markdown. The configuration included in the project automatically excludes content in a code block, enclosed in triple back quotes ```.

The configuration file also specifies that US English is the language used in the documentation, so only US English spellings should be used for words where alternate international English spellings exist.

You can add words to be considered valid either within a markdown document or within the cspell configuration file, cspell.json, in the root folder of the documentation repository.

Words defined within a page only apply to that page, but words added to the configuration file apply to the entire project.

Adding local words¶

You can add a list of words to be considered valid for spell checking purposes as a comment in a Markdown file.

The comment has a specific format to be picked up by the cSpell tool:

<!--- cSpell:ignore linkchecker linkcheckerrc mkdocs mkdoc -->

here the words linkchecker, linkcheckerrc, mkdocs and mkdoc are specified as words to be accepted by the spell checker within the file containing the comment.

Adding global words¶

The cSpell configuration file cspell.json contains a list of words that should always be considered valid when spell checking. The list of words applies to all files being checked.