daemon maintainer scripts: install init script + handle package removal/upgrade

This is supposed to fix the missing ngcp-mediaproxy-ng-daemon
link in /etc/rc2.d on CE systems.

While at it also try to handle restart/stop of service during
upgrades and package removals in a sane way. Needs extensive
testing though.

From: Michael Prokop <mprokop@sipwise.com>

debian/ngcp-mediaproxy-ng-daemon.postinst

@@ -3,8 +3,7 @@
 
 set -e
 
-# DEBHELPER like wrapper
-init_wrapper() {
+restart_handler() {
   if [ -x "/etc/init.d/ngcp-mediaproxy-ng-daemon" ]; then
     if [ -x "$(which invoke-rc.d 2>/dev/null)" ]; then
       invoke-rc.d ngcp-mediaproxy-ng-daemon restart || exit $?
@@ -14,16 +13,24 @@ init_wrapper() {
   fi
 }
 
-restart_daemon() {
-  # just invoke init script wrapper on ce systems since
+initscript_handler() {
+  if [ -x "/etc/init.d/ngcp-mediaproxy-ng-daemon" ]; then
+    update-rc.d ngcp-mediaproxy-ng-daemon defaults >/dev/null
+    invoke-rc.d ngcp-mediaproxy-ng-daemon start || exit $?
+  fi
+}
+
+init_handler() {
+  # just invoke init script wrappers on ce systems since
   # they do not provide ngcp-check_active and we don't
   # have to handle inactive nodes
   if ! [ -x "$(which ngcp-check_active 2>/dev/null)" ]; then
-    init_wrapper
+    restart_handler
+    initscript_handler
   else # do not restart daemon on inactive node in pro systems
     if ngcp-check_active ; then
       echo "Active node detected, restarting ngcp-mediaproxy-ng-daemon"
-      init_wrapper
+      restart_handler
     else
       echo "Inactive node detected, ignoring request to restart ngcp-mediaproxy-ng-daemon"
     fi
@@ -32,7 +39,7 @@ restart_daemon() {
 
 case "$1" in
     configure)
-      restart_daemon
+      init_handler
     ;;
 
     abort-upgrade|abort-remove|abort-deconfigure)
@@ -43,3 +50,5 @@ case "$1" in
         exit 1
     ;;
 esac
+
+exit 0

debian/ngcp-mediaproxy-ng-daemon.postrm

@@ -0,0 +1,18 @@
+#!/bin/sh
+# postrm script for ngcp-mediaproxy-ng-daemon
+
+set -e
+
+removal_wrapper() {
+  # remove the init script only on ce systems, as the
+  # the pro system handle it inside the monitoring/HA setup
+  if ! [ -x "$(which ngcp-check_active 2>/dev/null)" ]; then
+    update-rc.d ngcp-mediaproxy-ng-daemon remove >/dev/null
+  fi
+}
+
+if [ "$1" = "purge" ] ; then
+  removal_wrapper
+fi
+
+exit 0

debian/ngcp-mediaproxy-ng-daemon.prerm

@@ -0,0 +1,33 @@
+#!/bin/sh
+# prerm script for ngcp-mediaproxy-ng-daemon
+
+set -e
+
+stop_handler() {
+  if [ -x "/etc/init.d/ngcp-mediaproxy-ng-daemon" ]; then
+    invoke-rc.d ngcp-mediaproxy-ng-daemon stop || exit $?
+  fi
+}
+
+stop_daemon() {
+  # just stop the service on ce systems because
+  # the pro system handle it as part of their monitoring/HA setup
+  if ! [ -x "$(which ngcp-check_active 2>/dev/null)" ]; then
+    stop_handler
+  else
+    case "$2" in
+      upgrade)
+	echo "Detected upgrade procedure, not stopping ngcp-mediaproxy-ng-daemon service."
+	;;
+      remove|purge)
+        stop_handler
+	;;
+    esac
+  fi
+}
+
+if [ "$1" = "prerm" ] ; then
+  stop_daemon
+fi
+
+exit 0