uptimer.sh

#!/bin/bash

options=':i:s:d:n:p:h:'
while getopts ${options} option
do
    case ${option} in
        i) interval=$OPTARG;;
        s) site=$OPTARG;;
        d) domain=$OPTARG;;
        n) nameservers=$OPTARG;;
        p) site_ip=$OPTARG;;
        *) echo "Usage: uptimer.sh -s [site] -i [interval] -d [domain] -n [\"nameserver1 nameserver2\"] -s [site ip]"; exit;;
    esac
done



function post_to_slack() {
    SLACK_MESSAGE="\`\`\`$1\`\`\`"
    SLACK_URL=https://hooks.slack.com/services/[API_KEY]
    case "$2" in
    INFO)
        SLACK_ICON=':slack:'
        ;;
    WARNING)
        SLACK_ICON=':warning:'
        ;;
    ERROR)
        SLACK_ICON=':bangbang:'
        ;;
    *)
        SLACK_ICON=':slack:'
        ;;
    esac
    curl -X POST --data "payload={\"text\": \"${SLACK_ICON} ${SLACK_MESSAGE}\"}" ${SLACK_URL}
}

function check_http() {
    result=$(curl -I --silent $site | grep HTTP | awk '{print $2}')
    if [[ ${result} != 200 ]]; then
        post_to_slack "Uh oh! We received a ${result} for ${site}!" 
    fi
}



function check_dns() {
    for ns in ${nameservers[@]}; do
        ns_result=$(dig +short ${domain} @${ns})
        if [[ ${ns_result} != ${site_ip} ]]; then
            echo "ns=${ns}"
            echo "nsresult=${ns_result}"
            post_to_slack "Uh oh! ${domain} is not resolving to ${site_ip} on ${ns}!"
        fi
    done
}

while [[ x==0 ]]; do
    if [[ -z ${interval} ]]; then
        echo "Interval not specified with -i."; exit 1
    fi
    if [[ ! -z ${site} ]]; then
        check_http
    fi
    if [[ ${#nameservers[@]} != 0 ]]; then
        check_dns
    fi
    sleep $interval
done