Validate password less authentication with n number of hosts.

@Gowtham

If you’re using a bash script to check the status, you could use something relatively simple, such as:

checkSsh()
{
    local username="${1}"
    local hostname="${2}"
    local privatekey="${3}"
    local checkConn=$(ssh ${username}@${hostname} -i ${privatekey} "echo 2>&1" && echo UP || DOWN)

    if [ "${checkConn}" == "DOWN" ];
    then
        # Action taken when host is down.
        echo DOWN
    else
        # Action taken when host is up.
        echo UP
    fi
}

checkSsh "${1}" "${2}" "${3}"

You’d then pass on the details:

./checkssh.sh root 111.222.333.444 /path/to/key

You could even reduce that down to:

if ssh ${1}@${2} -i ${3} "echo 2>&1"; then
    echo UP
else
    echo DOWN
fi

And replace the echo UP|DOWN with whatever action you needed to perform. Or, if the user you’re trying to login as to test is always the same:

if ssh root@${1} -i ${2} "echo 2>&1"; then
    echo UP
else
    echo DOWN
fi