nlbwmon: receive dhcp interface triggers

Not all interfaces may have been allocated address at nlbwmon startup so
it may not collect statistics as expected/configured.

Add interface triggers to catch dhcp events and restart as required.

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
(cherry picked from commit 662d3f16d2)

net/nlbwmon/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=nlbwmon
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/jow-/nlbwmon.git

net/nlbwmon/files/nlbwmon.init

@@ -89,3 +89,19 @@ start_service() {
 	procd_close_instance
 }
 
+add_interface_trigger() {
+	local interface ignore
+
+	config_get interface "$1" interface
+	config_get_bool ignore "$1" ignore 0
+
+	[ -n "$interface" -a $ignore -eq 0 ] && procd_add_interface_trigger "interface.*" "$interface" /etc/init.d/nlbwmon reload
+}
+
+service_triggers() {
+	procd_add_reload_trigger "dhcp" "system"
+
+	config_load dhcp
+	config_foreach add_interface_trigger dhcp
+}
+