Add plugin docs section on configuration options
This commit adds a subsubsection to the plugin interface docs to
elaborate a bit on how to deal with configuration options. Previously,
how to use them in a plugin was implied, but nothing was explicitly
stated. This corrects that to make it clear on how to deal with
configuration.
Change-Id: Id3afc9657c5419cfba61acb3c84ccfea104d1b20
diff --git a/doc/source/plugin.rst b/doc/source/plugin.rst
index 4e97dbe..f92f63e 100644
--- a/doc/source/plugin.rst
+++ b/doc/source/plugin.rst
@@ -91,6 +91,21 @@
of the tempest developer and reviewer documentation to ensure that the tests
being added in the plugin act and behave like the rest of tempest.
+Dealing with configuration options
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Historically Tempest didn't provide external guarantees on its configuration
+options. However, with the introduction of the plugin interface this is no
+longer the case. An external plugin can rely on using any configuration option
+coming from Tempest, there will be at least a full deprecation cycle for any
+option before it's removed. However, just the options provided by Tempest
+may not be sufficient for the plugin. If you need to add any plugin specific
+configuration options you should use the ``register_opts`` and
+``get_opt_lists`` methods to pass them to Tempest when the plugin is loaded.
+When adding configuration options the ``register_opts`` method gets passed the
+CONF object from tempest. This enables the plugin to add options to both
+existing sections and also create new configuration sections for new options.
+
Using Plugins
=============