[grid] Using non-loopback address when default config is used

The `--hub` flag was introduced just before the 4.0.0 release,
and this implicitly made the use of `0.0.0.0` as the default
IP for the Hub and hence the Grid.

When someone tried to connect to a remote Grid, through the
`RemoteWebDriver.builder()`, an error was happening since
the `Augmenter` makes the `RemoteWebDriver` connect to
`se:cdp`. Given that the Grid url was `http://0.0.0.0:4444`,
the client was trying to connect to `ws://0.0.0.0:4444/session/...`,
which caused a failure.

This fixes that by retrieving the non-loopback address of the machine,
under the assumption that Hub and Nodes are on the same machine. If the
Hub and Nodes are on different machines, or inside Docker containers,
the users will need to configure the Grid url themselves
(through `--grid-url`).

Fixes #9976

Author: diemol

java/src/org/openqa/selenium/grid/node/config/NodeOptions.java

@@ -29,6 +29,7 @@
 import org.openqa.selenium.Platform;
 import org.openqa.selenium.SessionNotCreatedException;
 import org.openqa.selenium.WebDriver;
+import org.openqa.selenium.WebDriverException;
 import org.openqa.selenium.WebDriverInfo;
 import org.openqa.selenium.grid.config.Config;
 import org.openqa.selenium.grid.config.ConfigException;
@@ -37,6 +38,7 @@
 import org.openqa.selenium.internal.Require;
 import org.openqa.selenium.json.Json;
 import org.openqa.selenium.json.JsonOutput;
+import org.openqa.selenium.net.NetworkUtils;
 import org.openqa.selenium.net.Urls;
 import org.openqa.selenium.remote.service.DriverService;
 
@@ -120,7 +122,22 @@ public Optional<URI> getPublicGridUri() {
           baseUri.getQuery(),
           baseUri.getFragment());
       }
-
+      String nonLoopbackAddress = "0.0.0.0";
+      if (nonLoopbackAddress.equals(baseUri.getHost())) {
+        try {
+          nonLoopbackAddress = new NetworkUtils().getNonLoopbackAddressOfThisMachine();
+        } catch (WebDriverException ignore) {
+          // ignore this path as we still use "0.0.0.0"
+        }
+        baseUri = new URI(
+          baseUri.getScheme(),
+          baseUri.getUserInfo(),
+          nonLoopbackAddress,
+          baseUri.getPort(),
+          baseUri.getPath(),
+          baseUri.getQuery(),
+          baseUri.getFragment());
+      }
       return Optional.of(baseUri);
     } catch (URISyntaxException e) {
       throw new ConfigException("Unable to construct public URL: " + base);

java/test/org/openqa/selenium/grid/node/config/NodeOptionsTest.java

@@ -17,7 +17,16 @@
 
 package org.openqa.selenium.grid.node.config;
 
+import static java.util.Collections.emptyMap;
+import static java.util.Collections.emptySet;
+import static java.util.Collections.singletonMap;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.fail;
+import static org.junit.Assume.assumeFalse;
+import static org.junit.Assume.assumeTrue;
+
 import com.google.common.collect.ImmutableMap;
+
 import org.assertj.core.api.Condition;
 import org.junit.Test;
 import org.mockito.Mockito;
@@ -38,6 +47,7 @@
 import org.openqa.selenium.grid.node.SessionFactory;
 import org.openqa.selenium.internal.Either;
 import org.openqa.selenium.json.Json;
+import org.openqa.selenium.net.NetworkUtils;
 
 import java.io.StringReader;
 import java.net.URI;
@@ -48,14 +58,6 @@
 import java.util.Map;
 import java.util.Optional;
 
-import static java.util.Collections.emptyMap;
-import static java.util.Collections.emptySet;
-import static java.util.Collections.singletonMap;
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.Assert.fail;
-import static org.junit.Assume.assumeFalse;
-import static org.junit.Assume.assumeTrue;
-
 @SuppressWarnings("DuplicatedCode")
 public class NodeOptionsTest {
 
@@ -472,6 +474,20 @@ public void settingTheHubFlagSetsTheGridUrlAndEventBusFlags() {
       .isEqualTo(Optional.of(URI.create("http://cheese.com:4444")));
   }
 
+  @Test
+  public void settingTheHubWithDefaultValueSetsTheGridUrlToTheNonLoopbackAddress() {
+    String[] rawConfig = new String[]{
+      "[node]",
+      "hub = \"http://0.0.0.0:4444\"",
+      };
+    Config config = new TomlConfig(new StringReader(String.join("\n", rawConfig)));
+    String nonLoopbackAddress = new NetworkUtils().getNonLoopbackAddressOfThisMachine();
+    String nonLoopbackAddressUrl = String.format("http://%s:4444", nonLoopbackAddress);
+    NodeOptions nodeOptions = new NodeOptions(config);
+    assertThat(nodeOptions.getPublicGridUri())
+      .isEqualTo(Optional.of(URI.create(nonLoopbackAddressUrl)));
+  }
+
   private Condition<? super List<? extends Capabilities>> supporting(String name) {
     return new Condition<>(
       caps -> caps.stream().anyMatch(cap -> name.equals(cap.getBrowserName())),