wg-installer: install cronjob

Install a cronjob that removes unused wireguard interfaces every 10
minutes.

Signed-off-by: Nick Hainke <vincent@systemli.org>

net/wg-installer/Makefile

@@ -39,6 +39,9 @@ define Package/wg-installer-server/install
 
 	$(INSTALL_DIR) $(1)/etc/config
 	$(INSTALL_CONF) ./wg-server/config/wgserver.conf $(1)/etc/config/wgserver
+
+	$(INSTALL_DIR) $(1)/etc/init.d
+	$(INSTALL_BIN) ./wg-server/config/wgserver.init $(1)/etc/init.d/wgserver
 endef
 
 define Package/wg-installer-server/conffiles

net/wg-installer/wg-server/config/wgserver.init

@@ -0,0 +1,12 @@
+#!/bin/sh /etc/rc.common
+
+START=99
+
+# install cleanup script that executes every 10 min
+boot() {
+    test -f /etc/crontabs/root || touch /etc/crontabs/root
+    grep -q '/usr/share/wginstaller/wg.sh cleanup_wginterfaces' /etc/crontabs/root || {
+        echo "*/10 * * * *	/usr/share/wginstaller/wg.sh cleanup_wginterfaces" >> /etc/crontabs/root
+    }
+    /etc/init.d/cron restart
+}