Merge pull request #41 from runk/check-last-modified

feat: Skip download new databases if existing are up to date

Author: Dmitry Shirokov

scripts/postinstall.js

@@ -36,29 +36,66 @@ const link = (edition) =>
  `https://download.maxmind.com/app/geoip_download?edition_id=${edition}&license_key=${licenseKey}&suffix=tar.gz`;
 
 const selected = getSelectedDbs();
-const links = ['City', 'Country', 'ASN']
+const editionIds = ['City', 'Country', 'ASN']
  .filter((e) => selected.includes(e))
- .map((e) => link(`GeoLite2-${e}`));
+ .map((e) => `GeoLite2-${e}`);
 
 const downloadPath = path.join(__dirname, '..', 'dbs');
 
 if (!fs.existsSync(downloadPath)) fs.mkdirSync(downloadPath);
 
 const download = (url) =>
  new Promise((resolve) => {
- https.get(url, function (response) {
+ https.get(url, (response) => {
  resolve(response.pipe(zlib.createGunzip({})));
  });
  });
 
-console.log('Downloading maxmind databases...');
-links.forEach((url) =>
- download(url).then((result) =>
+// https://dev.maxmind.com/geoip/updating-databases?lang=en#checking-for-the-latest-release-date
+const isOutdated = async (dbPath, url) => {
+ if (!fs.existsSync(dbPath)) return true;
+
+ const remoteLastModified = await new Promise((resolve, reject) => {
+ https
+ .request(url, { method: 'HEAD' }, (res) =>
+ resolve(Date.parse(res.headers['last-modified']))
+ )
+ .on('error', (err) => reject(err))
+ .end();
+ });
+ const localLastModified = fs.statSync(dbPath).mtimeMs;
+
+ return localLastModified < remoteLastModified;
+};
+
+const main = async () => {
+ console.log('Downloading maxmind databases...');
+ for (const editionId of editionIds) {
+ const dbPath = path.join(downloadPath, `${editionId}.mmdb`);
+ const isOutdatedStatus = await isOutdated(dbPath, link(editionId));
+
+ if (!isOutdatedStatus) {
+ console.log(' > %s: Is up to date, skipping download', editionId);
+ continue;
+ }
+ console.log(' > %s: Is either missing or outdated, downloading', editionId);
+
+ const result = await download(link(editionId));
  result.pipe(tar.t()).on('entry', (entry) => {
  if (entry.path.endsWith('.mmdb')) {
  const dstFilename = path.join(downloadPath, path.basename(entry.path));
  entry.pipe(fs.createWriteStream(dstFilename));
+ entry.on('end', () => {});
  }
- })
- )
-);
+ });
+ }
+};
+
+main()
+ .then(() => {
+ // success
+ })
+ .catch((err) => {
+ console.error(err);
+ process.exit(1);
+ });