Cloudflare Zone Updater

cloudflare-zone-updater.sh

#!/bin/bash

Host="lora"
Domain="theodin.network"
User="<--Cloudflare-Username-->"
Key="<--Cloudflare-API-Key-->"

###############################################################################################

Missing=''
if [ ! -x /usr/bin/jq ]; then
    Missing="${Missing} jq"
fi
if [ ! -x /usr/bin/dig ]; then
    Missing="${Missing} dnsutils"
fi
if [ `echo ${Missing} |wc -w` -gt 0 ]; then
    echo "Missing:${Missing}"
    sudo apt update; sudo apt -y install ${Missing}
fi

###############################################################################################

LocalIP=`curl -sL "https://checkip.amazonaws.com"`
DNSIP=`dig ${Host}.${Domain} @1.1.1.1 @1.0.0.1 +short`

if [ "${DNSIP}" != "${LocalIP}" ]; then
    ZoneID=`curl -sX GET "https://api.cloudflare.com/client/v4/zones" -H "X-Auth-Email: ${User}" -H "X-Auth-Key: ${Key}" \
        -H "Content-Type: application/json" |jq ".result | .[] | select(.name == \"${Domain}\" ) .id" |sed 's/"//g'`
    RemoteIP=`curl -sX GET "https://api.cloudflare.com/client/v4/zones/${ZoneID}/dns_records" -H "X-Auth-Email: ${User}" \
        -H "X-Auth-Key: ${Key}" -H "Content-Type: application/json" \
        |jq ".result | .[] | select(.name == \"${Host}.${Domain}\" ).content" |sed 's/"//g'`
    if [ "${RemoteIP}" != "${LocalIP}" ]; then
        HostID=`curl -sX GET "https://api.cloudflare.com/client/v4/zones/${ZoneID}/dns_records" -H "X-Auth-Email: ${User}" \
            -H "X-Auth-Key: ${Key}" -H "Content-Type: application/json" \
            |jq ".result | .[] | select(.name == \"${Host}.${Domain}\" ) .id" |sed 's/"//g'`
        Data="{\"type\":\"A\",\"name\":\"${Host}.${Domain}\",\"content\":\"${LocalIP}\",\"ttl\":120,\"proxied\":false}"
        Output=`curl -sL -X PUT "https://api.cloudflare.com/client/v4/zones/${ZoneID}/dns_records/${HostID}" \
            -H "X-Auth-Email: ${User}" -H "X-Auth-Key: ${Key}" -H "Content-Type: application/json"  --data ${Data}`
        TEST=`echo ${Output} |jq -c '{success} | .[]'`
        if [ "${TEST}" == "true" ]; then
            echo "DNS record for ${Host}.${Domain} has been updated from ${RemoteIP} to ${LocalIP}!"
        else
            echo "DNS update failed"
            echo "The DNS record to be updated was ${Host}.${Domain}."
            echo "Tried to change the address form ${RemoteIP} to ${LocalIP}!"
            echo -n "The error message is: "
            echo ${Output} |jq '.errors |.[] .message'
        fi
    else
        echo "The DNS IP address (${DNSIP}) dose not match the remote IP address (${RemoteIP}) or the local IP Address (${LocalIP})"
        echo "This was most likly caused if we just updated the record but the DNS server hasn't updated yet"
    fi
fi