Logstash Reference [7.0] » Contributing to Logstash » Documenting your plugin
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Documenting your plugin

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

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

Documentation file

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 IDs

Format heading anchors with variables that can support generated IDs. This approachcreates unique IDs when the Logstash Versioned Plugin Referenceis 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 Referencebuilds correctly the first time. The second time the doc build runs, the IDis flagged as a duplicate, and the build fails.

Link formats

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

Link to content in the same file

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 Guide

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 text

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/7.0/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 descriptions

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 thecorrect syntax.

Code samples

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?

Plugin documentation goes through several steps before it gets published in theLogstash 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 updates

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

Resources

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

For tips on contributing and changelog guidelines, seeCONTRIBUTING.md.

For general information about contributing, seeContributing to Logtash.

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