Sync grains every start and highstate once automatically.

etc_salt_master.d_reactor.conf

reactors:
  # Run this script every time an abc instance starts
  - 'salt/minion/abc*/start':
    - '/srv/salt/reactors/abc/start.sls'
  # Run this script every time an abc instance returns from a job
  - 'salt/job/*/ret/abc*':
    - '/srv/salt/reactors/abc/ret.sls'

srv_salt_reactors_abc_ret.sls

{%- if data['fun'] == 'saltutil.sync_grains' %}
run_highstate:
  cmd.state.apply:
    - tgt: {{ data['id'] }}
    - arg:
      - reactors.first_run_highstate
    # Only needed for the custom environment
    - kwarg:
        saltenv: abc
{%- endif %}

srv_salt_reactors_abc_start.sls

first:
  local.saltutil.sync_grains:
    - tgt: {{ data['id'] }}
    # Only need this kwarg because of the custom environment
    - kwarg:
        saltenv: abc