dodns.js

/*
 * Uses Digital Ocean APIv2.
 *
 */
const configuration = require("./config/dodns.conf.js");

async function request(endpoint, options) {
  const response = await fetch(endpoint, options);
  if (response.status === 200) {
    return response.json();
  } else {
    throw new Error("Something went wrong on API server!");
  }
}

async function retreiveDODomainRecords(token, domainName) {
  // DO Domain Record Query Example:
  // curl -X GET -H "Content-Type: application/json" -H "Authorization: Bearer b7d03a6947b217efb6f3ec3bd3504582" "https://api.digitalocean.com/v2/domains/example.com/records"
  const options = {
    method: "GET",
    headers: {
      Authorization: `Bearer ${token}`,
    },
  };

  return request(`https://api.digitalocean.com/v2/domains/${domainName}/records`, options);
}

async function updateDORecord(token, domainName, domainRecordId, changeset) {
  // DO Domain Record Update API Example:
  // curl -X PUT -H "Content-Type: application/json" -H "Authorization: Bearer b7d03a6947b217efb6f3ec3bd3504582" -d '{"name":"blog"}' "https://api.digitalocean.com/v2/domains/example.com/records/3352896"
  const options = {
    body: JSON.stringify(changeset),
    method: "PUT",
    headers: {
      "Content-Type": "application/json; charset=utf-8",
      Authorization: `Bearer ${token}`,
    },
  };

  console.log("Updating", changeset);
  return request(`https://api.digitalocean.com/v2/domains/${domainName}/records/${domainRecordId}`, options);
}

function updateDOConfiguration(ip) {
  console.log(`${new Date().toLocaleString()}: Updating Digital Ocean DNS configuration to ${ip}...`);

  const requests = configuration.domains.map((domain) => {
    console.log(`Updating Digital Ocean DNS configuration for ${domain.domain}...`);
    return retreiveDODomainRecords(configuration.doPublicToken, domain.domain).then((domainRecords) => {
      const subdomainRequests = [];
      domain.subdomains.forEach((subdomain) => {
        // find a record for the subdomin
        const doRecord = domainRecords.domain_records.find((record) => record.name === subdomain);
        if (!doRecord || doRecord.type !== "A") {
          console.warn("No A record found for subdomain: '" + subdomain + "'")
          return;
        }

        if (doRecord.data === ip) {
          // already has the same IP, nothing to update.
          console.log(`\t'${subdomain}' already on same IP`);
          return;
        }

        // update the record with the new IP
        const updateRecord = {
          data: ip,
        };

        const updatePromise = updateDORecord(
          configuration.doPublicToken,
          domain.domain,
          doRecord.id,
          updateRecord
        ).then((response) => console.log(`\t'${subdomain}' updated.`, response));
        subdomainRequests.push(updatePromise);
      });

      if (subdomainRequests.length === 0) {
        console.log("\tno subdomains updated (nothing found, or already on same IP)!");
      }
      return Promise.all(subdomainRequests);
    });
  });

  return Promise.all(requests);
}

async function fetchExternalIP() {
  // IP from ipify.org
  // it's a JSON object, format: { "ip": "X.X.X.X" }
  return request("https://api.ipify.org?format=json").then((response) => response.ip);
}

//////////////////////////////////////////////////////////////////////////////////////////////////

// Configuration validation
if (!configuration) {
  console.error("ERR: Missing configuration (it's looking for a JS file @ ./config/dodns.conf.js)!");
  return 1;
}
if (!configuration.doPublicToken) {
  console.error("ERR: Invalid configuration, missing Digital Ocean Public API Token!");
  return 1;
}

// Let's go
fetchExternalIP()
  .then(updateDOConfiguration)
  .catch((error) => {
    console.error("ERR:", error);
  });