Updated Hamachi keep-alive script

Last Updated on June 25, 2010.

I modified the hamachi wrapper script with two functionalities:

• do NOT restart hamachi if there is nobody to ping
• DO restart hamachi if there are unreachable hosts
• DO restart hamachi if its CPU usage goes over 50% - this partly solves the 100% CPU usage problem of hamachi
• if you modify the script name, the script should keep working - it even works if there is a space in the filename

#!/bin/bash

scriptname="`basename \"$0\"`"

function command_pids {
IFS='
'
RES=""
for p in `ps xo pid,command | grep "$1"`; do
    IFS=' ' hampid=( $p )
    pid=${hampid[0]}
    if [ ".`basename ${hampid[1]}`" == ".hamachi" ]; then RES="${RES} $pid"; fi
done
echo $RES;
}

function hamachi_force_terminate {
    hamachi stop >/dev/null
    sleep 1
    for ham_pid in $( command_pids hamachi ); do
        kill -9 $ham_pid
    done
}

hamachi_running=1
if [ `echo $( command_pids hamachi ) | wc -w` -eq 0 ]; then
    hamachi_running=0;
    #echo "count not detect running hamachi"
else
    hamachi_pcpu=`ps ho pcpu $( command_pids hamachi )`
    if [ `echo $( command_pids hamachi ) | wc -w` -gt 1 ]; then
        echo "multiple running hamachi instances - terminating"
        hamachi_force_terminate
        hamachi_running=0
    else
        if [ `echo "$hamachi_pcpu > 50" | bc` -eq 1 ]; then 
            echo "high CPU usage hamachi instances - terminating"
            hamachi_force_terminate
            hamachi_running=0
        fi
    fi
fi

if [ `ip r | grep default -c` -lt 1 ]; then
    # No internet gateway, exiting!
    exit 1
fi

hamachi_online=`hamachi list | egrep '\* [0-9]' | awk '{print $2}'`
count_unreachable=`hamachi list | egrep 'x [0-9]' | wc -l`

ping_ok=1
for IP in $hamachi_online; do
    ping -c 2 $IP >/dev/null
    if [ $? -ne 0 ]; then
        echo "ping $IP failed!"
        hamachi list | grep $IP
        ping_ok=0;
    fi # if first ping fails then ping is not OK!
    break;
done

if [ $hamachi_running -ne 1 -o $count_unreachable -gt 0 -o $ping_ok -eq 0 ]; then
    echo "restarting hamachi: running $hamachi_running unreachable $count_unreachable ping $ping_ok"
    if [ `pgrep tuncfg | wc -l` -eq 0 ]; then sudo /sbin/tuncfg; fi
    hamachi_force_terminate
    hamachi start
    CNT=1;
    echo -n "Logging in... " ;
    while [ `hamachi login | grep -c failed` -eq 1 -a $CNT -lt 100 ]; do 
        echo -n "$CNT "; 
        let CNT=$CNT+1; 
        sleep 2; 
    done;
    sleep 2;
    echo
    hamachi get-nicks
#else
    #echo "hamachi is online"
fi