Documentation for plugins-parameters

In this changeset, I updated the documentation to explain how to
add configuration options for each type of plugin.

Partially Implements: plugins-parameters

Change-Id: Ifd373da64207110492b4a62f1cb7f13b029a45d2

doc/source/deploy/gmr.rst

@@ -0,0 +1,52 @@
+..
+      Except where otherwise noted, this document is licensed under Creative
+      Commons Attribution 3.0 License.  You can view the license at:
+
+          https://creativecommons.org/licenses/by/3.0/
+
+.. _watcher_gmr:
+
+=======================
+Guru Meditation Reports
+=======================
+
+Watcher contains a mechanism whereby developers and system administrators can
+generate a report about the state of a running Watcher service. This report
+is called a *Guru Meditation Report* (*GMR* for short).
+
+Generating a GMR
+================
+
+A *GMR* can be generated by sending the *USR2* signal to any Watcher process
+with support (see below).  The *GMR* will then be outputted as standard error
+for that particular process.
+
+For example, suppose that ``watcher-api`` has process id ``8675``, and was run
+with ``2>/var/log/watcher/watcher-api-err.log``.  Then, ``kill -USR2 8675``
+will trigger the Guru Meditation report to be printed to
+``/var/log/watcher/watcher-api-err.log``.
+
+Structure of a GMR
+==================
+
+The *GMR* is designed to be extensible; any particular service may add its
+own sections.  However, the base *GMR* consists of several sections:
+
+Package
+  Shows information about the package to which this process belongs, including
+  version informations.
+
+Threads
+  Shows stack traces and thread ids for each of the threads within this
+  process.
+
+Green Threads
+  Shows stack traces for each of the green threads within this process (green
+  threads don't have thread ids).
+
+Configuration
+  Lists all the configuration options currently accessible via the CONF object
+  for the current process.
+
+Plugins
+  Lists all the plugins currently accessible by the Watcher service.