add commandscripting docu

docs/commandscripting.rst

@@ -0,0 +1,51 @@
+.. _commandscripting:
+
+
+Command scripting
+=================
+
+VyOS supports executing configuration and operational commands non-interactively from shell scripts.
+
+To include VyOS-specific functions and aliases you need to ``source /opt/vyatta/etc/functions/script-template`` files at the top of your script.
+
+.. code-block:: sh
+
+  #!/bin/vbash
+  source /opt/vyatta/etc/functions/script-template
+
+  exit
+
+Run configuration commands
+--------------------------
+
+Configuration commands are executed just like from a normal config session.
+
+For example, if you want to disable a BGP peer on VRRP transition to backup:
+
+.. code-block:: sh
+
+  #!/bin/vbash
+  source /opt/vyatta/etc/functions/script-template
+
+  configure
+
+  set protocols bgp 65536 neighbor 192.168.2.1 shutdown
+
+  commit
+
+  exit
+
+
+Run operational commands
+------------------------
+
+Unlike a normal configuration sessions, all operational commands must be prepended with ``run``, even if you haven't created a session with configure.
+
+.. code-block:: sh
+
+  #!/bin/vbash
+  source /opt/vyatta/etc/functions/script-template
+
+  run show interfaces
+
+  exit

docs/index.rst

@@ -30,6 +30,7 @@ as a router and firewall platform for cloud deployments.
     high-availability.rst
     clustering.rst
     image-mgmt.rst
+    commandscripting.rst
     troubleshooting.rst
     examples.rst
     commandtree/index.rst

docs/system/task-scheduler.rst

@@ -4,7 +4,8 @@
 Task scheduler
 --------------
 
-Task scheduler — allows scheduled task execution. Note that scripts excecuted this way are executed as root user - this may be dangerous.
+| Task scheduler — allows scheduled task execution. Note that scripts excecuted this way are executed as root user - this may be dangerous.
+| Together with :ref:`commandscripting` this can be used for automating configuration.
 
 .. code-block:: sh