update-cloudflare-dns

#!/bin/bash

usage() {
    echo "Update Cloudflare DNS."
    echo ""
    echo "Usage: update-cloudflare-dns -t <token> -z <zone> -d <domain>"
    echo "       token       the Cloudflare API token"
    echo "       zone        the Cloudflare Zone ID"
    echo "       domain      the domain name"
}

base_url=https://api.cloudflare.com/client/v4
check_ip_url=http://api.ipify.org

while getopts ":t:z:d:" opt; do
    case "${opt}" in
        t) api_token="${OPTARG}";;
        z) zone_id="${OPTARG}";;
        d) domain_name="${OPTARG}";;
    esac
done

if [ -z "$api_token" ] || [ -z "$zone_id" ] || [ -z "$domain_name" ]; then
    usage
    exit 1
fi

invoke_cloudflare_api() {
    curl -sL -H "Content-Type: application/json" -H "Authorization: Bearer $api_token" $@
}

public_ip=$(curl -sL $check_ip_url)
record_id=$(
    invoke_cloudflare_api "$base_url/zones/$zone_id/dns_records" | \
    jq --arg name "$domain_name" -r -c '.result | .[] | select(.type == "A" and .name == $name) | .id'
)
ttl=900
request="{\"id\":\"$record_id\",\"type\":\"A\",\"name\":\"$domain_name\",\"content\":\"$public_ip\",\"ttl\":$ttl,\"proxied\":false}"

echo $request | jq
response=$(invoke_cloudflare_api -X PUT "$base_url/zones/$zone_id/dns_records/$record_id" -d $request)
echo $response | jq