Salt: Control a Linux Minion

To control a Salt Minion after install and configuration, setup a state tree:

Configure the Salt Master

In this example we will define two environments: base and 'ubuntu'
Enable these environments via the 'top file':

1. Create the needed directories for the config files:
   mkdir /srv/salt
2. Uncomment/add the necessary lines in the master config file:
   
   vi /etc/salt/master
   #Find file_roots: /fileroots
   file_roots:
     base:
       - /srv/salt
3. Restart the master to enable the change:
   pkill salt-master
   salt-master -d

Create the 'top' file:

1. Create a 'top.sls' file:
   vi /srv/salt/top.sls
2. Add in the declarations the environment:
   base:
     '*':
       - global
       - salt.minion
     'os:Ubuntu':
       - match: grain
       - linux/ubuntu

This tells salt that for the environment called base all minions will have state files /srv/salt/global.sls and /srv/salt/salt/minion.sls applied to them.

All systems that match the 'grain' of Ubuntu all Minions will have the state file /srv/salt/linux/ubuntu.sls or /srv/salt/linux/ubuntu/init.sls applied to them.

Create the State Files

1. Create the ubuntu state files:
   vi /srv/salt/global.sls
   vi /srv/salt/salt/minion.sls
   vi /srv/salt/repos/ubuntu.sls
2. Create the ubuntu state tree:
   vi /srv/salt/repos/ubuntu.sls
   unattended-upgrades:       # ID declaration
     pkg:                # state declaration
       - installed       # function declaration

Configure the Salt Minion

Use Cron on the Minion to enforce the Salt Master configuration:

sudo crontab -e

Insert the following line to run it hourly:

00 * * * * salt-call state.highstate

You can also issue this command manually from the Salt Master:
salt '*' state.highstate
or on the Minion:
salt-call state.highstate

Troubleshooting

salt-minion -l debug &          # On the Minion

salt '*' state.highstate -t 60  # On the Master

Useful Commands

• Get all services available for configuration on a Minion:
  salt [Minion hostname] service.get_all

Running Commands on the Minion

Salt cheatsheet by Valentin Höbel