cf-worker-ddns.js

async function handleRequest(request, env) {
  const url = new URL(request.url);
  const domain = url.searchParams.get('domain');
  const ip = url.searchParams.get('ip') || request.headers.get('CF-Connecting-IP');
  const type = url.searchParams.get('type') || (isIPv6(ip) ? 'AAAA' : 'A');
  const token = url.searchParams.get('token') || env.API_TOKEN;

  if (!domain) {
    return new Response('Missing domain query parameter', { status: 400 });
  }

  try {
    const updateResult = await updateDNSRecord(token, ip, domain, type);
    return new Response(updateResult.message, {
      headers: { 'Content-Type': 'text/plain' },
    });
  } catch (error) {
    return new Response(error.message, { status: 500 });
  }
}

async function findZoneIdByDomain(token, domain) {
  const endpoint = `https://api.cloudflare.com/client/v4/zones?name=${domain}&status=active`;
  const response = await fetch(endpoint, {
    headers: {
      'Authorization': `Bearer ${token}`,
      'Content-Type': 'application/json',
    },
  });
  const data = await response.json();
  if (!data.success) {
    throw new Error('Failed to fetch zone details');
  }
  if (data.result.length > 0) {
    return data.result[0].id; // Return the Zone ID of the matched domain
  } else {
    throw new Error('No matching zone found');
  }
}

async function updateDNSRecord(token, ip, domain, type) {
  const zoneId = await findZoneIdByDomain(token, domain);
  const dnsRecord = await findDNSRecord(token, zoneId, domain, type);
  console.log("dnsRecord.content:" , dnsRecord.content, ip);
  if (dnsRecord.content === ip) {
    return { success: true, message: 'IP address is the same, update skipped' };
  }
  const endpoint = `https://api.cloudflare.com/client/v4/zones/${zoneId}/dns_records/${dnsRecord.id}`;
  const response = await fetch(endpoint, {
    method: 'PUT',
    headers: {
      'Authorization': `Bearer ${token}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      type: type,
      name: domain,
      content: ip,
      ttl: 1, // 1 means automatic
    }),
  });

  const data = await response.json();
  if (!data.success) {
    throw new Error('Failed to update DNS record');
  }
  return { success: true, message: 'DNS record updated successfully' };
}

async function findDNSRecord(token, zoneId, domain, type) {
  const endpoint = `https://api.cloudflare.com/client/v4/zones/${zoneId}/dns_records?name=${domain}&type=${type}`;
  const response = await fetch(endpoint, {
    headers: {
      'Authorization': `Bearer ${token}`,
      'Content-Type': 'application/json',
    },
  });
  const data = await response.json();
  if (!data.success || data.result.length === 0) {
    throw new Error('DNS record not found');
  }
  return data.result[0]; // Assuming the first record is the one we want to update
}

function isIPv6(ip) {
  return ip.includes(':');
}

export default {
  fetch: handleRequest
}