Do not override DAEMON_ARGS through /etc/default files
After adding support we faced broken configuration for openstack
services (see related bug). OS services' init.d files "sources"
/etc/defaults/{service_name} files which could override DAEMON_ARGS.
Change-Id: I79f76cd0c51d5080291ba5b18930e614cb8b8924
Related-bug: PROD-17968
diff --git a/heat/files/default b/heat/files/default
index 9284a0f..eabb6aa 100644
--- a/heat/files/default
+++ b/heat/files/default
@@ -1,4 +1,4 @@
# Generated by Salt.
{% if values.logging.log_appender %}
-DAEMON_ARGS="--log-config-append=/etc/heat/logging/logging-{{ service_name }}.conf"
-{% endif %}
\ No newline at end of file
+DAEMON_ARGS="${DAEMON_ARGS} --log-config-append=/etc/heat/logging/logging-{{ service_name }}.conf"
+{% endif %}