mtr-mon.sh

#!/bin/bash

function log {
        echo "[$(date +%F\ %T)]" $* >&2
}

function warn {
        log "[!]" $*
}

function die {
        warn $*
        exit ${EXIT_CODE_ERROR}
}

LOG_DIR='/var/log/mtr'
MTR_CNT='1000'
MTR_INT='0.1'
PATH='/sbin:/bin:/usr/sbin:/usr/bin'

if [[ ! -d "${LOG_DIR}" ]]; then
        if [[ -f "${LOG_DIR}" ]]; then
                die "The ${LOG_DIR} is present, but it's not a directory"
        fi
else
        mkdir -p "${LOG_DIR}"
        if [[ "${?}" -ne 0 ]]; then
                die "Can't create the ${LOG_DIR} directory"
        fi
fi

for TARGET in 8.8.8.8 8.8.4.4; do
        MTR_RESULT="$(mtr -r -c "${MTR_CNT}" -i "${MTR_INT}" "${TARGET}")"
        if [[ "${?}" -ne 0 ]]; then
                die "Can't trace the route to ${TARGET}"
        fi
        TIMESTAMP="$(date +%Y%m%d%H%M%S)"
        RATES=()
        echo "${MTR_RESULT}" > "${LOG_DIR}/result-${TARGET}-${TIMESTAMP}"
        for HOP in $(cat "${LOG_DIR}/result-${TARGET}-${TIMESTAMP}" | sed -n -r 's/^[[:space:]]*[[:digit:]]+\.[[:space:]]+([[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3})[[:space:]]+([[:digit:]]{1,3}\.[[:digit:]])%?[[:space:]]+.*$/\1:\2/gp'); do
                HOST="$(echo "${HOP}" | cut -d ':' -f 1)"
                RATE="$(echo "${HOP}" | cut -d ':' -f 2)"
                RATES+=($(printf '%.0f' "${RATE}"))
        done
        RATE_PEAK=0
        RATE_LAST=100
        for (( I=${#RATES[@]}-1; I>=0 ;I-- )); do
                [[ ${RATES[I]} -gt $((${RATE_LAST} * 4)) ]] && continue
                [[ ${RATES[I]} -gt ${RATE_PEAK} ]] && RATE_PEAK="${RATES[I]}"
                RATE_LAST="${RATES[I]}"
        done
        if [[ ${RATE_PEAK} -gt 1 ]]; then
                cat "${LOG_DIR}/result-${TARGET}-${TIMESTAMP}" | mail -r 'xxx@xxx' -s "Too many packets have been lost while tracing the route to ${TARGET}" "xxx@xxx"
        fi
done