The Salt Syndic interface is a powerful tool which allows for the construction of Salt command topologies. A basic Salt setup has a Salt Master commanding a group of Salt Minions. The Syndic interface is a special passthrough minion, it is run on a master and connects to another master, then the master that the Syndic minion is listening to can control the minions attached to the master running the syndic.
The intent for supporting many layouts is not presented with the intent of supposing the use of any single topology, but to allow a more flexible method of controlling many systems.
Since the Syndic only needs to be attached to a higher level master the configuration is very simple. On a master that is running a syndic to connect to a higher level master the syndic_master option needs to be set in the master config file. The syndic_master option contains the hostname or IP address of the master server that can control the master that the syndic is running on.
The master that the syndic connects to sees the syndic as an ordinary minion, and treats it as such. the higher level master will need to accept the syndic's minion key like any other minion. This master will also need to set the order_masters value in the configuration to True. The order_masters option in the config on the higher level master is very important, to control a syndic extra information needs to be sent with the publications, the order_masters option makes sure that the extra data is sent out.
The Syndic is a separate daemon that needs to be started on the master that is controlled by a higher master. Starting the Syndic daemon is the same as starting the other Salt daemons.
# salt-syndic