rpcbind: make service socket activated

Instead of setting 'Restart=always' in the service file, we should
make the service socket activated, just like what Fedora does.

(From OE-Core rev: 176e91ef28800adb6295b29c455b2efb91a01876)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/rpcbind/rpcbind/rpcbind.service

@@ -1,15 +1,12 @@
 [Unit]
-Description=RPC Bind
-After=network.target
-Wants=rpcbind.target
-Before=rpcbind.target
+Description=RPC Bind Service
+Requires=rpcbind.socket
 
 [Service]
 Type=forking
 EnvironmentFile=-@SYSCONFDIR@/rpcbind.conf
 ExecStart=@SBINDIR@/rpcbind -w $RPCBIND_OPTS
-Restart=always
 SuccessExitStatus=2
 
 [Install]
-WantedBy=multi-user.target
+Also=rpcbind.socket

meta/recipes-extended/rpcbind/rpcbind/rpcbind.socket

@@ -0,0 +1,8 @@
+[Unit]
+Description=RPCbind Server Activation Socket
+
+[Socket]
+ListenStream=/var/run/rpcbind.sock
+
+[Install]
+WantedBy=sockets.target

meta/recipes-extended/rpcbind/rpcbind_0.2.1.bb

@@ -15,6 +15,7 @@ SRC_URI = "${SOURCEFORGE_MIRROR}/rpcbind/rpcbind-${PV}.tar.bz2 \
            file://init.d \
            ${UCLIBCPATCHES} \
            file://rpcbind.conf \
+           file://rpcbind.socket \
            file://rpcbind.service \
           "
 
@@ -34,8 +35,7 @@ PACKAGECONFIG[tcp-wrappers] = "--enable-libwrap,--disable-libwrap,tcp-wrappers"
 INITSCRIPT_NAME = "rpcbind"
 INITSCRIPT_PARAMS = "start 12 2 3 4 5 . stop 60 0 1 6 ."
 
-SYSTEMD_SERVICE_${PN} = "rpcbind.service"
-SYSTEMD_AUTO_ENABLE = "disable"
+SYSTEMD_SERVICE_${PN} = "rpcbind.service rpcbind.socket"
 
 inherit useradd
 
@@ -56,6 +56,7 @@ do_install_append () {
 
 	install -m 0755 ${WORKDIR}/rpcbind.conf ${D}${sysconfdir}
 	install -d ${D}${systemd_unitdir}/system
+	install -m 0644 ${WORKDIR}/rpcbind.socket ${D}${systemd_unitdir}/system
 	install -m 0644 ${WORKDIR}/rpcbind.service ${D}${systemd_unitdir}/system
 	sed -i -e 's,@SBINDIR@,${sbindir},g' \
 		-e 's,@SYSCONFDIR@,${sysconfdir},g' \