Add call routing API endpoint for turn servers

service/src/main/java/org/whispersystems/textsecuregcm/geo/MaxMindDatabaseManager.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.geo;
+
+import com.maxmind.db.CHMCache;
+import com.maxmind.geoip2.DatabaseReader;
+import com.maxmind.geoip2.GeoIp2Provider;
+import io.dropwizard.lifecycle.Managed;
+import io.micrometer.core.instrument.Metrics;
+import io.micrometer.core.instrument.Timer;
+import org.apache.commons.compress.archivers.ArchiveEntry;
+import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
+import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;
+import org.whispersystems.textsecuregcm.configuration.MonitoredS3ObjectConfiguration;
+import org.whispersystems.textsecuregcm.metrics.MetricsUtil;
+import org.whispersystems.textsecuregcm.s3.S3ObjectMonitor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import javax.annotation.Nonnull;
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Supplier;
+
+public class MaxMindDatabaseManager implements Supplier<DatabaseReader>, Managed {
+
+  private final S3ObjectMonitor databaseMonitor;
+
+  private final AtomicReference<DatabaseReader> databaseReader = new AtomicReference<>();
+
+  private final String databaseTag;
+
+  private final Timer refreshTimer;
+
+  private static final Logger log = LoggerFactory.getLogger(MaxMindDatabaseManager.class);
+
+  public MaxMindDatabaseManager(
+      @Nonnull final ScheduledExecutorService executorService,
+      @Nonnull final MonitoredS3ObjectConfiguration configuration,
+      @Nonnull final String databaseTag
+  ){
+    this.databaseMonitor = new S3ObjectMonitor(
+        configuration.s3Region(),
+        configuration.s3Bucket(),
+        configuration.objectKey(),
+        configuration.maxSize(),
+        executorService,
+        configuration.refreshInterval(),
+        this::handleDatabaseChanged
+    );
+
+    this.databaseTag = databaseTag;
+    this.refreshTimer = Metrics.timer(MetricsUtil.name(MaxMindDatabaseManager.class), "refresh", databaseTag);
+  }
+
+  private void handleDatabaseChanged(final InputStream inputStream) {
+    refreshTimer.record(() -> {
+      boolean foundDatabaseEntry = false;
+
+      try (final InputStream bufferedInputStream = new BufferedInputStream(inputStream);
+          final GzipCompressorInputStream gzipInputStream = new GzipCompressorInputStream(bufferedInputStream);
+          final TarArchiveInputStream tarInputStream = new TarArchiveInputStream(gzipInputStream)) {
+
+        ArchiveEntry nextEntry;
+
+        while ((nextEntry = tarInputStream.getNextEntry()) != null) {
+          if (nextEntry.getName().toLowerCase().endsWith(".mmdb")) {
+            foundDatabaseEntry = true;
+
+            final DatabaseReader oldReader = databaseReader.getAndSet(
+                new DatabaseReader.Builder(tarInputStream).withCache(new CHMCache()).build()
+            );
+            if (oldReader != null) {
+              oldReader.close();
+            }
+            break;
+          }
+        }
+      } catch (final IOException e) {
+        log.error(String.format("Failed to load MaxMind database, tag %s", databaseTag));
+      }
+
+      if (!foundDatabaseEntry) {
+        log.warn(String.format("No .mmdb entry loaded from input stream, tag %s", databaseTag));
+      }
+    });
+  }
+
+  @Override
+  public void start() throws Exception {
+    Managed.super.start();
+    databaseMonitor.start();
+  }
+
+  @Override
+  public void stop() throws Exception {
+    Managed.super.stop();
+    databaseMonitor.stop();
+
+    final DatabaseReader reader = databaseReader.getAndSet(null);
+    if(reader != null) {
+      reader.close();
+    }
+  }
+
+  @Override
+  public DatabaseReader get() {
+    return this.databaseReader.get();
+  }
+}