Debian fix: Enable dnsmasq systemd unit on install.

debian/changelog

-dnsmasq (2.70-3) unstable; urgency=low
+dnsmasq (2.70-3) unstable; urgency=medium
 
    * Write a pid-file, even when being started using systemd, since
      other components may wish to signal dnsmasq.
-	
- -- Simon Kelley <simon@thekelleys.org.uk>  Fri, 09 May 2014 20:45:11 +0000
+   * Enable dnsmasq systemd unit on install. Otherwise dnsmasq does not run on
+     fresh installations (without administrator handholding) and even worse it
+     is disabled on systems switching from sysv to systemd. Modify
+     postinst/postrm exactly as dh_systemd would, add dependency on
+     init-system-helpers. Closes: #724602
+
+ -- Simon Kelley <simon@thekelleys.org.uk> Sun, 11 May 2014 17:45:21 +0000
 
 dnsmasq (2.70-2) unstable; urgency=low
 

debian/control

@@ -2,13 +2,15 @@ Source: dnsmasq
 Section: net
 Priority: optional
 Build-depends: gettext, libnetfilter-conntrack-dev [linux-any],
-               libidn11-dev, libdbus-1-dev (>=0.61), libgmp-dev, nettle-dev (>=2.4-3)
+               libidn11-dev, libdbus-1-dev (>=0.61), libgmp-dev, 
+               nettle-dev (>=2.4-3)
 Maintainer: Simon Kelley <simon@thekelleys.org.uk>
 Standards-Version: 3.9.3
 
 Package: dnsmasq
 Architecture: all
-Depends: netbase, dnsmasq-base(>= ${binary:Version})
+Depends: netbase, dnsmasq-base(>= ${binary:Version}),
+         init-system-helpers (>= 1.18~)
 Suggests: resolvconf
 Conflicts: resolvconf (<<1.15)
 Description: Small caching DNS proxy and DHCP/TFTP server

debian/postinst

 #!/bin/sh
 set -e
 
+# Code copied from dh_systemd_enable ----------------------
+# This will only remove masks created by d-s-h on package removal.
+deb-systemd-helper unmask dnsmasq.service >/dev/null || true
+
+# was-enabled defaults to true, so new installations run enable.
+if deb-systemd-helper --quiet was-enabled dnsmasq.service; then
+	# Enables the unit on first installation, creates new
+	# symlinks on upgrades if the unit file has changed.
+	deb-systemd-helper enable dnsmasq.service >/dev/null || true
+else
+	# Update the statefile to add new symlinks (if any), which need to be
+	# cleaned up on purge. Also remove old symlinks.
+	deb-systemd-helper update-state dnsmasq.service >/dev/null || true
+fi
+# End code copied from dh_systemd_enable ------------------
+
 if [ -x /etc/init.d/dnsmasq ]; then
    update-rc.d dnsmasq defaults 15 85 >/dev/null
 

debian/postrm

@@ -4,3 +4,19 @@ set -e
 if [ purge = "$1" ]; then
    update-rc.d dnsmasq remove >/dev/null
 fi
+
+# Code copied from dh_systemd_enable ----------------------
+if [ "$1" = "remove" ]; then
+	if [ -x "/usr/bin/deb-systemd-helper" ]; then
+		deb-systemd-helper mask dnsmasq.service >/dev/null
+	fi
+fi
+
+if [ "$1" = "purge" ]; then
+	if [ -x "/usr/bin/deb-systemd-helper" ]; then
+		deb-systemd-helper purge dnsmasq.service >/dev/null
+		deb-systemd-helper unmask dnsmasq.service >/dev/null
+	fi
+fi
+# End code copied from dh_systemd_enable ------------------
+