[[plugin-authors]]
== Help for plugin authors

The Elasticsearch repository contains examples of:

* a https://github.com/elastic/elasticsearch/tree/master/plugins/site-example[site plugin]
  for serving static HTML, JavaScript, and CSS.
* a https://github.com/elastic/elasticsearch/tree/master/plugins/jvm-example[Java plugin]
  which contains Java code.

These examples provide the bare bones needed to get started.  For more
information about how to write a plugin, we recommend looking at the plugins
listed in this documentation for inspiration.

[NOTE]
.Site plugins
====================================

The example site plugin mentioned above contains all of the scaffolding needed
for integrating with Maven builds.  If you don't plan on using Maven, then all
you really need in your plugin is:

* The `plugin-descriptor.properties` file
* The `_site/` directory
* The `_site/index.html` file

====================================

[float]
=== Plugin descriptor file

All plugins, be they site or Java plugins, must contain a file called
`plugin-descriptor.properties` in the root directory. The format for this file
is described in detail  here:

https://github.com/elastic/elasticsearch/blob/master/dev-tools/src/main/resources/plugin-metadata/plugin-descriptor.properties[`dev-tools/src/main/resources/plugin-metadata/plugin-descriptor.properties`].

Either fill in this template yourself (see
https://github.com/lmenezes/elasticsearch-kopf/blob/master/plugin-descriptor.properties[elasticsearch-kopf]
as an example) or, if you are using Elasticsearch's Maven build system, you
can fill in the necessary values in the `pom.xml` for your plugin. For
instance, see
https://github.com/elastic/elasticsearch/blob/master/plugins/site-example/pom.xml[`plugins/site-example/pom.xml`].

[float]
=== Loading plugins from the classpath

When testing a Java plugin, it will only be auto-loaded if it is in the
`plugins/` directory.  If, instead, it is in your classpath, you can tell
Elasticsearch to load it with the `plugin.types` setting:

[source,java]
--------------------------
settingsBuilder()
    .put("cluster.name", cluster)
    .put("path.home", getHome())
    .put("plugin.types", MyCustomPlugin.class.getName()) <1>
    .build();
--------------------------
<1> Tells Elasticsearch to load your plugin.