A bash script to update a Cloudflare DNS A record with the external IP of the source machine

cloudflare-ddns-update.sh

    #!/bin/bash
    # based on https://gist.github.com/Tras2/cba88201b17d765ec065ccbedfb16d9a
    # initial data; they need to be filled by the user
    #### Added multiple sub domains and proxy state set options
    ## API token; e.g. FErsdfklw3er59dUlDce44-3D43dsfs3sddsFoD3
    api_token=<>
    ## the email address associated with the Cloudflare account; e.g. [email protected]
    email=<>
    ## the zone (domain) should be modified; e.g. example.com
    zone_name=example.com
    ## the dns record (sub-domain) should be modified; e.g. sub.example.com
    hostname=(a.example.com,b.example.com)
    ## Set Proxy for the hostname to 'true' or 'false'
    proxy=true
    # get the basic data
    ipv4=$(curl -s -X GET -4 https://checkip.amazonaws.com --max-time 30)
    ipv6=$(curl -s -X GET -6 https://ifconfig.co --max-time 30) 
    user_id=$(curl -s -X GET "https://api.cloudflare.com/client/v4/user/tokens/verify" \
               -H "Authorization: Bearer $api_token" \
               -H "Content-Type:application/json" \
          | jq -r '{"result"}[] | .id'
         )

    # write down IPv4 and/or IPv6
    if [ $ipv4 ]; then echo -e "\033[0;32m [+] Your public IPv4 address: $ipv4"; else echo -e "\033[0;33m [!] Unable to get any public IPv4 address."; fi
    if [ $ipv6 ]; then echo -e "\033[0;32m [+] Your public IPv6 address: $ipv6"; else echo -e "\033[0;33m [!] Unable to get any public IPv6 address."; fi

    # check if the user API is valid and the email is correct
    if [ $user_id ]
        then
            zone_id=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=$zone_name&status=active" \
                   -H "Content-Type: application/json" \
                   -H "X-Auth-Email: $email" \
                   -H "Authorization: Bearer $api_token" \
              | jq -r '{"result"}[] | .[0] | .id'
             )

    for dns_record in ${hostname//,/ }  ##--> Beginning of the for loop to process all hostnames

        do
   
            echo  -e "\033[0;35m Working on $dns_record"

    # check if the zone ID is avilable
    if [ $zone_id ]
        then
    # check if there is any IP version 4
        if [ $ipv4 ]
        then
            dns_record_a_id=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$zone_id/dns_records?type=A&name=$dns_record"  \
                               -H "Content-Type: application/json" \
                               -H "X-Auth-Email: $email" \
                               -H "Authorization: Bearer $api_token"
                             )
    # if the IPv4 exist
                dns_record_a_ip=$(echo $dns_record_a_id |  jq -r '{"result"}[] | .[0] | .content')
                    if [ $dns_record_a_ip != $ipv4 ]
                    then
    # change the A record
                    curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$zone_id/dns_records/$(echo $dns_record_a_id | jq -r '{"result"}[] | .[0] | .id')" \
                    -H "Content-Type: application/json" \
                    -H "X-Auth-Email: $email" \
                    -H "Authorization: Bearer $api_token" \
                    --data "{\"type\":\"A\",\"name\":\"$dns_record\",\"content\":\"$ipv4\",\"ttl\":1,\"proxied\":$proxy}" \
                    | jq -r '.errors'
    # write the result
                echo -e "\033[0;32m [+] The IPv4 is successfully set on Cloudflare as the A Record with the value of:    $dns_record_a_ip"
            else
                echo -e "\033[0;37m [~] The current IPv4 and  the existing on on Cloudflare are the same; there is no need to apply it."
            fi
        fi
            
        # check if there is any IP version 6
        if [ $ipv6 ]
        then
            dns_record_aaaa_id=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$zone_id/dns_records?type=AAAA&name=$dns_record"  \
                                      -H "Content-Type: application/json" \
                                      -H "X-Auth-Email: $email" \
                                      -H "Authorization: Bearer $api_token"
                                )
            # if the IPv6 exist
            dns_record_aaaa_ip=$(echo $dns_record_aaaa_id | jq -r '{"result"}[] | .[0] | .content')
            if [ $dns_record_aaaa_ip != $ipv6 ]
            then
                # change the AAAA record
                curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$zone_id/dns_records/$(echo $dns_record_aaaa_id | jq -r '{"result"}[] | .[0] | .id')" \
                     -H "Content-Type: application/json" \
                     -H "X-Auth-Email: $email" \
                     -H "Authorization: Bearer $api_token" \
                     --data "{\"type\":\"AAAA\",\"name\":\"$dns_record\",\"content\":\"$ipv6\",\"ttl\":1,\"proxied\":$proxy}" \
                | jq -r '.errors'
                # write the result
                echo -e "\033[0;32m [+] The IPv6 is successfully set on Cloudflare as the AAAA Record with the value of: $dns_record_aaaa_ip"
            else
                echo -e "\033[0;37m [~] The current IPv6 address and the existing on on Cloudflare are the same; there is no need to apply it."
            fi
        fi  
    else
        echo -e "\033[0;31m [-] There is a problem with getting the Zone ID (subdomain) or the email address (username). Check them and try again."
    fi

    done ###--> End of the for loop to process all hostnames

    else
        echo -e "\033[0;31m [-] There is a problem with either the API token. Check it and try again."
    fi