Documenting your pluginedit

Quality documentation with good examples contributes to the adoption of your plugin.

The documentation that you write for your plugin will be generated and published in the Logstash Reference and the Logstash Versioned Plugin Reference.

Documentation fileedit

Documentation is a required component of your plugin. It belongs in a single file called docs/index.asciidoc. The plugin generation utility creates a starter file for you.

Heading IDsedit

Format heading anchors with variables that can support generated IDs. This approach creates unique IDs when the Logstash Versioned Plugin Reference is built. Unique heading IDs are required to avoid duplication over multiple versions of a plugin.

Example

Don’t hardcode a heading ID like this: [[config_models]]

Instead, use variables to define it:

[id="plugins-{type}s-{plugin}-config_models"]
==== Configuration models

If you hardcode an ID, the Logstash Versioned Plugin Reference builds correctly the first time. The second time the doc build runs, the ID is flagged as a duplicate, and the build fails.

Link formatsedit

Correct link formatting is essential for directing users to the content you want them to see. Incorrect link formatting or duplicate links can break the documentation build. Let’s not do that.

Link to content in the same fileedit

Use angle brackets to format links to content in the same asciidoc file.

Example

This link:

<<plugins-{type}s-{plugin}-config_models>>

Points to this heading in the same file:

[id="plugins-{type}s-{plugin}-config_models"]
==== Configuration models

Link to content in the Logstash Reference Guideedit

Use external link syntax for links that point to documentation for other plugins or content in the Logstash Reference Guide.

Examples

{logstash-ref}/plugins-codecs-multiline.html[Multiline codec plugin]
{logstash-ref}/getting-started-with-logstash.html

Link textedit

If you don’t specify link text, the URL is used as the link text.

Examples

If you want your link to display as http://www.elastic.co/guide/en/logstash/7.1/getting-started-with-logstash.html, use this format:

{logstash-ref}/getting-started-with-logstash.html

If you want your link to display as Getting Started with Logstash, use this format:

{logstash-ref}/getting-started-with-logstash.html[Getting Started with Logstash]

Link to data type descriptionsedit

We make an exception for links that point to data type descriptions, such as <<boolean,boolean>>, because they are used so frequently. We have a cleanup step in the conversion script that converts the links to the correct syntax.

Code samplesedit

We all love code samples. Asciidoc supports code blocks and config examples. To include Ruby code, use the asciidoc [source,ruby] directive.

Note that the hashmarks (#) are present to make the example render correctly. Don’t include the hashmarks in your asciidoc file.

# [source,ruby]
# -----
# match => {
#  "field1" => "value1"
#  "field2" => "value2"
#  ...
# }
# -----

The sample above (with hashmarks removed) renders in the documentation like this:

match => {
  "field1" => "value1"
  "field2" => "value2"
  ...
}

Where’s my doc?edit

Plugin documentation goes through several steps before it gets published in the Logstash Versioned Plugin Reference and the Logstash Reference.

Here’s an overview of the workflow:

  • Be sure that you have signed the CLI and have all necessary approvals and sign offs.
  • Merge the pull request for your plugin (including the index.asciidoc file, the changelog.md file, and the gemspec).
  • Wait for the continuous integration build to complete successfully.
  • Publish the plugin to https://rubygems.org.
  • A script detects the new or changed version, and picks up the index.asciidoc file for inclusion in the doc build.
  • The documentation for your new plugin is published in the Logstash Versioned Plugin Reference.

We’re not done yet.

  • For each release, we package the new and changed documentation files into a pull request to add or update content. (We sometimes package plugin docs between releases if we make significant changes to plugin documentation or add a new plugin.)
  • The script detects the new or changed version, and picks up the index.asciidoc file for inclusion in the doc build.
  • We create a pull request, and merge the new and changed content into the appropriate version branches.
  • For a new plugin, we add a link to the list of plugins in the Logstash Reference.
  • The documentation for your new (or changed) plugin is published in the Logstash Reference.

Documentation or plugin updatesedit

When you make updates to your plugin or the documentation, consider bumping the version number in the changelog and gemspec (or version file). The version change triggers the doc build to pick up your changes for publishing.

Resourcesedit

For more asciidoc formatting tips, see the excellent reference at https://github.com/elastic/docs#asciidoc-guide.

For tips on contributing and changelog guidelines, see CONTRIBUTING.md.

For general information about contributing, see Contributing to Logtash.