Connect syndic minions to syndic master

Syndics are generally the masters assigned to their region.
We want the minions on syndics to connect to their upstream master
("master of masters") instead of to themselves.

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>

salt/profile/salt/minion.sls

@@ -1,7 +1,17 @@
+{%- set netbox_pillar = salt['pillar.get']('netbox') -%}
+{%- if 'custom_fields' in netbox_pillar and 'salt.syndic' in netbox_pillar['custom_fields']['salt_roles'] -%}
+{%- set master = salt['pillar.get']('salt:master:syndic_master') -%}
+{%- elif 'config_context' in netbox_pillar -%}
+{%- set master = netbox_pillar['config_context']['salt_master'] -%}
+{%- else -%}
+{%- do salt.log.warning('Could not determine Salt master') -%}
+{%- set master = 'FIX-ME.lysergic.dev' -%}
+{%- endif -%}
+
 /etc/salt/minion.d/master.conf:
   file.managed:
     - contents:
-      - 'master: {{ salt['pillar.get']('netbox:config_context:salt_master') }}'
+      - 'master: {{ master }}'
     - require_in:
       - service: salt-minion
     - watch_in: