[horizon] Allow to pass any setting to horizon local_settings.py

Change-Id: I164f3bb0af5d07af17490bd3d275c7b0fbadb0b9

horizon/values.yaml

@@ -223,6 +223,8 @@ conf:
               idp: "myidp2"
               protocol: "saml2"
         log_level: "DEBUG"
+        # Pass any settings to the end of local_settings.py
+        raw: {}
       template: |
         import os
 
@@ -922,6 +924,10 @@ conf:
         DISALLOW_IFRAME_EMBED = {{ .Values.conf.horizon.local_settings.config.disallow_iframe_embed }}
 
         STATIC_ROOT = '/var/www/html/horizon'
+
+        {{- range $option, $value := .Values.conf.horizon.local_settings.config.raw }}
+        {{ $option }} = {{ toJson $value }}
+        {{- end }}
     policy:
       ceilometer:
         context_is_admin: 'role:admin'