Script for testing if interface works ok and restart some services after interface recovers from failure.

restart-services.sh

#!/bin/bash

# script for checking if specified interface is UP and properly connected to network (so ping can work)
# enter test ping address. IF ping fails it's marked by creation of file. When ping starts working again
# it restart few services (domoticz, mosquitto, samba) and docker containers (you need to specify your
# own containers IDs).
# script also write to syslog when the ping fail first time (when interface failed), and when recovered.

# crontab entry for running every 1min:
# * * * * * /root/restart-services.sh >/dev/null 2>&1

# set to 1 to see more info (debug), not recommended when running from cron
DEBUG_MODE=0

PING_ADDR=192.168.2.1
PING_INTF=wlan0

ERR_FILE=/tmp/ping-error
LOG_FILE=/var/log/svr-rst-netfail.log

ping -4 -I $PING_INTF -c 2 -q -W 1 $PING_ADDR

PING_ERR=$?

if [ $DEBUG_MODE -ne 0 ]; then
        echo "PING result: $PING_ERR"
fi

if [ $PING_ERR -ne 0 ]; then
        if [ -a $ERR_FILE ]; then
                # do nothing
                echo "Still interface down."
        else
                touch /tmp/ping-error
                logger "Detected interface $PING_INTF failure, test ping failed."
                echo "$(date -Iseconds) : Detected interface $PING_INTF failure, test ping failed." >> $LOG_FILE
                if [ $DEBUG_MODE -ne 0 ]; then
                        echo "Logged error to syslog and created error-file: $ERR_FILE"
                fi
        fi
fi

#check if file exists indication last ping-error
if [ -a /tmp/ping-error ]; then
        if [ $DEBUG_MODE -ne 0 ]; then
                echo "Error file exists! Last ping failed."
        fi
        # check if ping above worked
        if [ $PING_ERR -eq 0 ]; then
                if [ $DEBUG_MODE -ne 0 ]; then
                        echo "Restarting services..."
                fi
                # if last ping-gateway was erro, but now it's ok
                # restart some services
                systemctl restart mosquitto
                SRV_MOS=$?
                systemctl restart domoticz
                SRV_DOM=$?
                systemctl restart smbd nmbd
                SRV_SMB=$?
                docker restart 3c060fc249a8
                DOC_R1=$?
                docker restart 0377a1652133
                DOC_R2=$?
                # delete file indication gateway ping-error
                rm -f /tmp/ping-error
                if [ $DEBUG_MODE -ne 0 ]; then
                        echo "Recovered from wifi failure, restart results: PING=$PING_ERR MOSQUITTO=$SRV_MOS DOMOTICZ=$SRV_DOM SMB=$SRV_SMB DOCKER=$DOC_R1 $DOC_R2"
                fi

                logger "Recovered from wifi failure, restart results: PING=$PING_ERR MOSQUITTO=$SRV_MOS DOMOTICZ=$SRV_DOM SMB=$SRV_SMB DOCKER=$DOC_R1 $DOC_R2"
                echo "$(date -Iseconds) : Recovered from wifi failure, restart results: PING=$PING_ERR MOSQUITTO=$SRV_MOS DOMOTICZ=$SRV_DOM SMB=$SRV_SMB DOCKER=$DOC_R1 $DOC_R2" >> $LOG_FILE
        fi
fi