Vyattacfg passed the wrong arguments for VRRP scripting

General questions
, ,
1

I’m trying to create a simple script to check if a VRRP router able to ping at least one IP/router before it considered as failed. However, the script doesn’t properly captured the correct number and values of passed arguments. I believe it relates to these lines here:

if [ "$(id -g -n)" != 'vyattacfg' ] ; then
    exec sg vyattacfg -c "/bin/vbash $(readlink -f $0) $@"
fi

Full Script:

#!/bin/vbash
echo "--------------------------------------------";
echo "Before vyattacfg";
echo "Number of address passed: ${#}";
echo $@;
echo "--------------------------------------------";

if [ "$(id -g -n)" != 'vyattacfg' ] ; then
    exec sg vyattacfg -c "/bin/vbash $(readlink -f $0) $@"
fi

# Requires at least 1 router loopback address (IPv4/IPv6).
# The script will exit with 0 (success) even though no router address is specified. So, be sure to correctly configure this.
# The best way to test this is to run the script and look at the exit code before applying it to VRRP.
# I don't bother checking whether the formatting of the address is correct or not.
# Check is considered failed if ping to ALL specified routers failed. If even 1 ping successful, the check considered a success.

NUM_OF_ARGS=$#;
ALL_ARGS=$@;

echo "--------------------------------------------";
echo "After vyattacfg";
echo "Number of address passed: ${NUM_OF_ARGS}";
echo $ALL_ARGS;
echo "--------------------------------------------";

ADD_TO_LOG () {
  echo "[$(date +%d/%m/%Y) $(date +%H:%M:%S)] ${1}" >> /var/log/scripts/vrrp-check.log
}

source /opt/vyatta/etc/functions/script-template;

if [ $NUM_OF_ARGS -lt 1 ]
then
    echo "Usage: $0 <RTR1_LOOPBACK_IP> <RTR2_LOOPBACK_IP> ...";
    echo "You need to specify at least 1 router IPv4/IPv6 address!";
    exit 0;
else
    RESULT_ARR=();
    for ARG in $ALL_ARGS
    do
        ADD_TO_LOG "Running ping to $ARG";
        /bin/ping -c 1 -i 1 $ARG;
        PING_RESULT=$?;
        ADD_TO_LOG "Ping to ${ARG}, result code: ${PING_RESULT}";
    done
fi

Test command:

sudo /config/scripts/vrrp-check.sh 10.0.5.32 10.0.5.33 10.0.5.34 10.0.5.35

Output:

--------------------------------------------
Before vyattacfg
Number of address passed: 4
10.0.5.32 10.0.5.33 10.0.5.34 10.0.5.35
--------------------------------------------
--------------------------------------------
Before vyattacfg
Number of address passed: 1
10.0.5.32
--------------------------------------------
--------------------------------------------
After vyattacfg
Number of address passed: 1
10.0.5.32
--------------------------------------------

Any idea how? Thank you

2

Hi all, can anyone experienced in writing the scripts help me on this. Thanks a lot.

3

Save the all-arguments $@ into a variable before the exec call works for me. I’m not sure if the issue is with the exec command or sg stopping taking arguments after the first numeric argument.

if [ "$(id -g -n)" != 'vyattacfg' ] ; then
    ALL_SCRIPT_ARGS=$@
    exec sg vyattacfg -c "/bin/vbash $(readlink -f $0) ${ALL_SCRIPT_ARGS}"
fi

Reading up on it, it’s bash/vbash: Stackoverflow > What is the difference between $* and $@

“There is no difference if you do not put $* or $@ in quotes. But if you put them inside quotes (which you should, as a general good practice), then $@ will pass your parameters as separate parameters, whereas $* will just pass all params as a single parameter.”

So using $* instead of $@ does the trick, too:

if [ "$(id -g -n)" != 'vyattacfg' ] ; then
    exec sg vyattacfg -c "/bin/vbash $(readlink -f $0) $*"
fi