Document sudo policy for gitfs post-recieve hook

doc/topics/tutorials/gitfs.rst

@@ -761,13 +761,29 @@ steps to this process:
          - 'salt/fileserver/gitfs/update':
            - /srv/reactor/update_fileserver.sls
 
-3. On the git server, add a `post-receive hook`_ with the following contents:
+3. On the git server, add a `post-receive hook`_
 
-   .. code-block:: bash
+   a. If the user executing `git push` is the same as the minion user, use the following hook:
 
-       #!/usr/bin/env sh
+     .. code-block:: bash
 
-       salt-call event.fire_master update salt/fileserver/gitfs/update
+         #!/usr/bin/env sh
+         salt-call event.fire_master update salt/fileserver/gitfs/update
+
+   b. To enable other git users to run the hook after a `push`, use sudo in the hook script: 
+     .. code-block:: bash
+
+         #!/usr/bin/env sh
+         sudo -u root salt-call event.fire_master update salt/fileserver/gitfs/update
+
+4. If using sudo in the git hook (above), the policy must be changed to permit all users to fire the event.
+   Add the following policy to the sudoers file on the git server.
+
+   .. code-block::
+
+       Cmnd_Alias SALT_GIT_HOOK = /bin/salt-call event.fire_master update salt/fileserver/gitfs/update
+       Defaults!SALT_GIT_HOOK !requiretty
+       ALL ALL=(root) NOPASSWD: SALT_GIT_HOOK
 
 The ``update`` argument right after :mod:`event.fire_master
 <salt.modules.event.fire_master>` in this example can really be anything, as it
@@ -777,6 +793,9 @@ by this reactor.
 Similarly, the tag name ``salt/fileserver/gitfs/update`` can be replaced by
 anything, so long as the usage is consistent.
 
+The ``root`` user name in the hook script and sudo policy should be changed to match the user under which 
+the minion is running.
+
 .. _`post-receive hook`: http://www.git-scm.com/book/en/Customizing-Git-Git-Hooks#Server-Side-Hooks
 
 .. _git-as-ext_pillar