chore: Use domain name from R2DBC connections when configuring the connector.

Author: hessjcg

r2dbc/core/src/main/java/com/google/cloud/sql/core/GcpConnectionFactoryProvider.java

@@ -124,11 +124,22 @@ public ConnectionFactory create(ConnectionFactoryOptions connectionFactoryOption
             ? RefreshStrategy.LAZY
             : RefreshStrategy.BACKGROUND;
 
+    final String r2dbcHostname = (String) connectionFactoryOptions.getRequiredValue(HOST);
+    final String cloudSqlInstance;
+    final String domainName;
+    if (CloudSqlInstanceName.isValidInstanceName(r2dbcHostname)) {
+      cloudSqlInstance = r2dbcHostname;
+      domainName = null;
+    } else {
+      cloudSqlInstance = null;
+      domainName = r2dbcHostname;
+    }
+
     Builder optionBuilder = createBuilder(connectionFactoryOptions);
-    String cloudSqlInstance = (String) connectionFactoryOptions.getRequiredValue(HOST);
     ConnectionConfig config =
         new ConnectionConfig.Builder()
             .withCloudSqlInstance(cloudSqlInstance)
+            .withDomainName(domainName)
             .withAuthType(enableIamAuth ? AuthType.IAM : AuthType.PASSWORD)
             .withIpTypes(ipTypes)
             .withNamedConnector(namedConnector)

r2dbc/core/src/test/java/com/google/cloud/sql/core/GcpConnectionFactoryProviderTest.java

@@ -33,6 +33,9 @@
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.ListeningScheduledExecutorService;
+import io.netty.handler.ssl.SslContextBuilder;
+import io.r2dbc.spi.ConnectionFactory;
+import io.r2dbc.spi.ConnectionFactoryOptions;
 import java.io.IOException;
 import java.math.BigInteger;
 import java.security.GeneralSecurityException;
@@ -49,6 +52,7 @@
 import java.util.Base64;
 import java.util.Date;
 import java.util.concurrent.ExecutionException;
+import java.util.function.Function;
 import javax.security.auth.x500.X500Principal;
 import org.bouncycastle.cert.X509CertificateHolder;
 import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter;
@@ -186,4 +190,32 @@ public void setup() throws GeneralSecurityException {
             InternalConnectorRegistry.DEFAULT_CONNECT_TIMEOUT_MS,
             defaultExecutor);
   }
+
+  public void testThings(){
+    GcpConnectionFactoryProvider provider = new GcpConnectionFactoryProvider() {
+      @Override
+      ConnectionFactory tcpSocketConnectionFactory(ConnectionConfig config,
+          ConnectionFactoryOptions.Builder optionBuilder,
+          Function<SslContextBuilder, SslContextBuilder> customizer) {
+        return null;
+      }
+
+      @Override
+      ConnectionFactory unixSocketConnectionFactory(ConnectionFactoryOptions.Builder optionBuilder,
+          String socket) {
+        return null;
+      }
+
+      @Override
+      ConnectionFactoryOptions.Builder createBuilder(
+          ConnectionFactoryOptions connectionFactoryOptions) {
+        return null;
+      }
+
+      @Override
+      boolean supportedProtocol(String protocol) {
+        return false;
+      }
+    }
+  }
 }