Add systemd service file

Allows openfortivpn to act as system service.
The configuration is expected under $(sysconfdir)/openfortivpn/<NAME>.conf.

https://www.freedesktop.org/software/systemd/man/daemon.html#Installing%20systemd%20Service%20Files

Makefile.am

@@ -28,23 +28,33 @@ etc/openfortivpn/config: $(srcdir)/etc/openfortivpn/config.template
 	@$(MKDIR_P) etc/openfortivpn
 	$(AM_V_GEN)$(SED) -e '3,$$ s/^/# /' $(srcdir)/etc/openfortivpn/config.template >$@
 
-install-data-hook: etc/openfortivpn/config
+lib/systemd/system/openfortivpn@.service: $(srcdir)/lib/systemd/system/openfortivpn@.service.in
+	$(MKDIR_P) lib/systemd/system
+	$(SED) -e 's|[@]SYSCONFDIR[@]|$(sysconfdir)|g' $(srcdir)/lib/systemd/system/openfortivpn@.service.in >$@
+
+install-data-hook: etc/openfortivpn/config lib/systemd/system/openfortivpn@.service
 	if ! test -f $(DESTDIR)$(confdir)/config ; then \
 		$(MKDIR_P) $(DESTDIR)$(confdir) ; \
 		$(INSTALL) -m 600 etc/openfortivpn/config \
 			$(DESTDIR)$(confdir)/config ; \
 	fi
+if HAVE_SYSTEMD
+	$(MKDIR_P) $(systemdsystemunitdir)
+	$(INSTALL) lib/systemd/system/openfortivpn@.service \
+	           $(systemdsystemunitdir)
+endif
 
 dist_man_MANS = doc/openfortivpn.1
 
 doc/openfortivpn.1: $(srcdir)/doc/openfortivpn.1.in
 	@$(MKDIR_P) doc
 	$(AM_V_GEN)$(SED) -e 's|[@]SYSCONFDIR[@]|$(sysconfdir)|g;s|[@]DATADIR[@]|$(datadir)|g' $(srcdir)/doc/openfortivpn.1.in >$@
 
-all-local: etc/openfortivpn/config
+all-local: etc/openfortivpn/config lib/systemd/system/openfortivpn@.service
 
 clean-local:
 	-rm -f etc/openfortivpn/config
+	-rm -f lib/systemd/system/openfortivpn@.service
 	-rm -f doc/openfortivpn.1
 
-EXTRA_DIST = autogen.sh CHANGELOG.md LICENSE LICENSE.OpenSSL README.md doc/openfortivpn.1.in $(data_DATA)
+EXTRA_DIST = autogen.sh CHANGELOG.md LICENSE LICENSE.OpenSSL README.md doc/openfortivpn.1.in $(data_DATA) lib/systemd/system/openfortivpn@.service

configure.ac

@@ -452,5 +452,21 @@ AS_IF([test "x$enable_resolvconf" = "xyes"], [
 	AC_MSG_NOTICE([USE_RESOLVCONF... 0])
 ])
 
+# install systemd service file
+AC_ARG_WITH([systemdsystemunitdir],
+	[AS_HELP_STRING([--with-systemdsystemunitdir=DIR], [Directory for systemd service files])],,
+	[with_systemdsystemunitdir=auto])
+AS_IF([test "x$with_systemdsystemunitdir" = "xyes" -o "x$with_systemdsystemunitdir" = "xauto"], [
+	def_systemdsystemunitdir=$($PKG_CONFIG --variable=systemdsystemunitdir systemd)
+
+	AS_IF([test "x$def_systemdsystemunitdir" = "x"],
+	AS_IF([test "x$with_systemdsystemunitdir" = "xyes"],
+		[AC_MSG_ERROR([systemd support requested but pkg-config unable to query systemd package])])
+		with_systemdsystemunitdir=no],
+	[with_systemdsystemunitdir="$def_systemdsystemunitdir"])])
+AS_IF([test "x$with_systemdsystemunitdir" != "xno"],
+	[AC_SUBST([systemdsystemunitdir], [$with_systemdsystemunitdir])])
+AM_CONDITIONAL([HAVE_SYSTEMD], [test "x$with_systemdsystemunitdir" != "xno"])
+
 AC_CONFIG_COMMANDS([timestamp], [touch src/.dirstamp])
 AC_OUTPUT(Makefile)

lib/systemd/system/openfortivpn@.service.in

@@ -0,0 +1,12 @@
+[Unit]
+Description=OpenFortiVPN for %I
+After=network-online.target
+
+[Service]
+Type=simple
+PrivateTmp=true
+ExecStart=/usr/bin/openfortivpn -c @SYSCONFDIR@/openfortivpn/%I.conf
+OOMScoreAdjust=-100
+
+[Install]
+WantedBy=multi-user.target