GUACAMOLE-1981: Add configure argument for systemd user

configure.ac

@@ -229,6 +229,14 @@ AC_ARG_WITH(systemd_dir,
 AM_CONDITIONAL([ENABLE_SYSTEMD], [test "x${systemd_dir}" != "x"])
 AC_SUBST(systemd_dir)
 
+# Systemd user
+AC_ARG_WITH(systemd_user,
+            [AS_HELP_STRING([--with-systemd-user=<username>],
+                            [the user configured in the systemd unit to run guacd @<:@default=daemon@:>@])],
+            [systemd_user=$withval],
+            [systemd_user=daemon])
+AC_SUBST(systemd_user)
+
 # guacd config file
 AC_ARG_WITH(guacd_conf,
             [AS_HELP_STRING([--with-guacd-conf=<path>],
@@ -1480,6 +1488,7 @@ AM_COND_IF([ENABLE_INIT], [build_init="${init_dir}"], [build_init=no])
 #
 
 AM_COND_IF([ENABLE_SYSTEMD], [build_systemd="${systemd_dir}"], [build_systemd=no])
+AM_COND_IF([ENABLE_SYSTEMD], [build_systemd_user="${systemd_user}"], [build_systemd_user=no])
 
 #
 # FreeRDP plugins
@@ -1531,6 +1540,7 @@ $PACKAGE_NAME version $PACKAGE_VERSION
    FreeRDP plugins: ${build_rdp_plugins}
    Init scripts: ${build_init}
    Systemd units: ${build_systemd}
+   Systemd user: ${build_systemd_user}
 
 Type \"make\" to compile $PACKAGE_NAME.
 "

src/guacd/Makefile.am

@@ -87,9 +87,12 @@ endif
 # Systemd service
 if ENABLE_SYSTEMD
 systemddir = @systemd_dir@
+systemduser = @systemd_user@
 systemd_DATA = systemd/guacd.service
 
 systemd/guacd.service: systemd/guacd.service.in
-	sed -e 's,[@]sbindir[@],$(sbindir),g' < systemd/guacd.service.in > systemd/guacd.service
+	sed -e 's,[@]sbindir[@],$(sbindir),g' \
+	 -e 's,[@]systemduser[@],$(systemduser),g' \
+	 < systemd/guacd.service.in > systemd/guacd.service
 endif
 

src/guacd/systemd/guacd.service.in

@@ -21,7 +21,7 @@ Documentation=man:guacd(8)
 After=network.target
 
 [Service]
-User=daemon
+User=@systemduser@
 ExecStart=@sbindir@/guacd -f
 Restart=on-abnormal