feat(ns-plug): restart service if connection goes down

Make sure that ns-plug always try to connect to the controller.
This fix will allow automatica re-connection in case
of disaster recovery of the remote controller.

#978

Author: stephdl

packages/ns-plug/Makefile

@@ -73,6 +73,7 @@ define Package/ns-plug/install
 	$(INSTALL_DIR) $(1)/usr/libexec/mwan-hooks
 	$(INSTALL_BIN) ./files/ns-plug.init $(1)/etc/init.d/ns-plug
 	$(INSTALL_BIN) ./files/ns-plug $(1)/usr/sbin/ns-plug
+	$(INSTALL_BIN) ./files/restart-ns-plug $(1)/usr/libexec/restart-ns-plug
 	$(INSTALL_BIN) ./files/distfeed-setup $(1)/usr/sbin/distfeed-setup
 	$(INSTALL_BIN) ./files/remote-backup $(1)/usr/sbin
 	$(INSTALL_BIN) ./files/send-backup $(1)/usr/sbin

packages/ns-plug/files/ns-plug

@@ -65,13 +65,11 @@ fi
 
 # Register the server
 valid=0
-max_attempts=30 # 60 seconds
-watchdog=0
 response=""
-until [ "${valid}" -eq 1 ] || [ "${watchdog}" -ge "${max_attempts}" ]
+until [ "${valid}" -eq 1 ]
 do
     response=$(curl ${curl_opts} -H "Content-Type: application/json" -H "RegistrationToken: ${token}" ${server}/api/units/register -X POST --data '{"unit_id": "'${unit_id}'", "username": "'${user}'", "password": "'${secret}'", "unit_name": "'${unit_name}'", "version": "'${VERSION_ID}'", "subscription_type": "'${subscription_type}'", "system_id": "'${system_id}'"}')
-    http_code=$(echo ${response} | jq -r .code)
+    http_code=$(echo ${response} | jq -r '.code // empty')
     if [ "${http_code}" == "409" ]; then
         # Duplicate entry, cleanup uci config
         uci delete rpcd.controller
@@ -82,15 +80,11 @@ do
     elif [ "${http_code}" == "200" ]; then
         valid=1
     else
-        sleep 2 # wait for controller to be reacheable
-	watchdog=$(( watchdog + 1 ))
+        logger -t ns-plug "Connection failed. Waiting for the controller ..."
+        sleep 5 # wait for controller to be reacheable
     fi
 done
 
-if  [ "${watchdog}" -ge "${max_attempts}" ]; then
-    exit 5
-fi
-
 # Save the new password after successfull registration
 uci set rpcd.controller.password=${passwd}
 uci commit rpcd
@@ -112,6 +106,7 @@ dev tun-nsplug
 tls-client
 script-security 2
 route-up /usr/sbin/ns-controller-push-info
+down "/usr/libexec/restart-ns-plug"
 <ca>
 ${ca}
 </ca>

packages/ns-plug/files/restart-ns-plug

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+#
+# Copyright (C) 2024 Nethesis S.r.l.
+# SPDX-License-Identifier: GPL-2.0-only
+#
+
+# Restart the ns-plug service when tun-nsplug goes down
+
+# the service can take a while to stop
+if /etc/init.d/ns-plug status ; then
+    sleep 30
+fi
+
+# Check if the service is NOT running
+if ! /etc/init.d/ns-plug status ; then
+    exit 0
+fi
+
+# Restart the service
+/etc/init.d/ns-plug restart