How to modify default options in Salt Minion config file from Master

I want to set "grains_cache" variable to "True" from Salt Master on all Minions. This variable is from default options that exist in minion config file and cannot be overridden by pillar data. So how can I set variables (for example "grains_cache", "grains_cache_expiration" or "log_file") from Master?

Solution

this should be an easy one. Manage the minion configuration file using the file.managed function. A simple sls should help here:

minion_configuration:
  file.managed:
    - name: /etc/salt/minion
    - contents: |
        grains_cache: true
        backup_mode: minion

salt-minion-restart:
  cmd.wait:
    - name: salt-call --local service.restart salt-minion
    - bg: True
    - order: last
    - watch:
      - file: salt-minion-config

In this example, saltstack ensures that the two lines beneath - contents: | are present within the minions configuration file.

The second state: salt-minion-restart will restart the salt-minion if the minion configuration file is being touched (managed by the first state). So in short terms, this state adds your variables to the minion's configuration and restarts the minion afterwards.

This formula is os-independent. The last thing left to do is, to target all of your minions with this.

If you want to know more about the cmd.wait and the shown example, please refer to this documentation.

I hope i could help.