flink-docs/README.md

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# Documentation generators

This module contains generators that create HTML files directly from Flink's source code.

## REST API documentation

The `RestAPIDocGenerator`/`OpenApiSpecGenerator` can be used to generate a full reference of the REST API of a `RestServerEndpoint`. A separate file is generated for each endpoint.

To integrate a new endpoint into the generator
1. Add a new `DocumentingRestEndpoint` class to `RestAPIDocGenerator` that extends the new endpoint class
2. Add another call to `createHtmlFile` in `RestAPIDocGenerator#main`
3. Regenerate the documentation by running `mvn package -Dgenerate-rest-docs -pl flink-docs -am -nsu -DskipTests`
4. Integrate the generated file into the REST API documentation by adding `{{< generated/<file-name> }}` to the corresponding markdown file.

The documentation must be regenerated whenever
* a handler is added to/removed from a `RestServerEndpoint`
* any used `MessageHeaders` class or any referenced `RequestBody`, `ResponseBody`, `MessageParameters` or `MessageParameter` class is modified.

## Configuration documentation

The `ConfigOptionsDocGenerator` can be used to generate a reference of `ConfigOptions`. By default, a separate file is generated for each `*Options` class found in `org.apache.flink.configuration` and `org.apache.flink.yarn.configuration`. The `@ConfigGroups` annotation can be used to generate multiple files from a single class.

To integrate an `*Options` class from another package, add another module-package argument pair to `ConfigurationOptionLocator#LOCATIONS`.

The files can be generated by running `mvn package -Dgenerate-config-docs -pl flink-docs -am -nsu -DskipTests -Pskip-webui-build`, and can be integrated into the documentation using `{{ include generated/<file-name> >}}`.

The documentation must be regenerated whenever
* an `*Options` class was added or removed
* a `ConfigOption` was added to or removed from an `*Options` class
* a `ConfigOption` was modified in any way.