Add documentation for the Minion data cache

Includes docs for localfs and consul minion data cache modules

doc/contents.rst

@@ -23,6 +23,7 @@ Salt Table of Contents
     ref/index
     topics/api
     topics/topology/index
+    topics/cache/index
     topics/windows/index
     topics/development/index
     topics/releases/index

doc/ref/cache/all/index.rst

@@ -0,0 +1,14 @@
+.. _all-salt.cache:
+
+=============
+cache modules
+=============
+
+.. currentmodule:: salt.cache
+
+.. autosummary::
+    :toctree:
+    :template: autosummary.rst.tmpl
+
+    localfs
+    consul

doc/ref/cache/all/salt.cache.consul.rst

@@ -0,0 +1,5 @@
+salt.cache.consul module
+========================
+
+.. automodule:: salt.cache.consul
+    :members:

doc/ref/cache/all/salt.cache.localfs.rst

@@ -0,0 +1,5 @@
+salt.cache.localfs module
+=========================
+
+.. automodule:: salt.cache.localfs
+    :members:

doc/ref/index.rst

@@ -10,6 +10,7 @@ This section contains a list of the Python modules that are used to extend the v
 
     ../ref/auth/all/index
     ../ref/beacons/all/index
+    ../ref/cache/all/index
     ../ref/engines/all/index
     ../ref/file_server/all/index
     ../ref/grains/all/index

doc/topics/cache/index.rst

@@ -0,0 +1,33 @@
+.. _cache:
+
+=================
+Minion Data Cache
+=================
+
+The Minion Data Cache contains the Salt Mine data and other minion info cached
+on the Salt master.  By default Salt uses the `localfs` cache module to save
+the data in a msgpack file on the Salt master.  Other external data stores can
+also be used to store this data such as the `Consul` module.
+
+See :ref:`cache modules <all-salt.cache>` for a current list.
+
+
+Configuring the Minion Data Cache
+=================================
+
+The default `localfs` Minion data cache module doesn't require any
+configuration.  External data cache modules with external data stores such as
+Consul require a configuration setting in the master config.
+
+Here's an exampls config for Consul:
+
+.. code-block:: yaml
+
+    consul.host: 127.0.0.1
+    consul.port: 8500
+    consul.token: None
+    consul.scheme: http
+    consul.consistency: default
+    consul.dc: dc1
+    consul.verify: True
+

salt/cache/consul.py

@@ -21,7 +21,7 @@ could be set in the master config, these are the defaults:
     consul.token: None
     consul.scheme: http
     consul.consistency: default
-    consul.dc: None
+    consul.dc: dc1
     consul.verify: True
 
 Related docs could be found here:

salt/cache/localfs.py

@@ -4,6 +4,9 @@ Cache data in filesystem.
 
 .. versionadded:: 2016.11.0
 
+The `localfs` Minion cache module is the default cache module and does not
+require any configuration.
+
 Expirations can be set in the relevant config file (``/etc/salt/master`` for
 the master, ``/etc/salt/cloud`` for Salt Cloud, etc).
 '''