Overlay structure for salt configurations

description.md

Problem

There are two sources of salt configurations: base and overlay.

The goal is to use the base states and pillar data but ignore the base top file, using only the top files from overlay repo.

Prerequisites

Filesystem layout

/srv/salt/
          base/
                states/
                        top.sls
                        base_state.sls
                        another_base_state.sls
                pillars/
                        top.sls
                        base_pillar.sls
                        another_base_pillar.sls
          overlay/
                states/
                        top.sls
                        overlay_state.sls
                pillars/
                        top.sls
                        overlay_pillar.sls

Salt master paths configuration

file_roots:
  base:
    - /srv/salt/base/states
  overlay:
    - /srv/salt/overlay/states

pillar_roots:
  base:
    - /srv/salt/base/pillars
  overlay:
    - /srv/salt/overlay/pillars
    
env_order: ['base','overlay']

/srv/salt/base/states/top.sls

base:
  '*':
    - base_state
    - another_base_state

/srv/salt/base is read only

Desired behaviour

salt '*' highstate should trigger base_state and overlay_state, but not another_base_state

Possible Solution

1. Configure salt-master to use another name for top.sls file Add to /etc/salt/master:

   state_top: overlay_top.sls
   

2. Create /srv/salt/overlay/states/overlay_top.sls

   base:
     '*':
       - base_state
   
   overlay:
     '*':
       - overlay_state

salt-master will read only this top-file and ignore all top.sls files in the base environment