Node WebSocket not working with sub-path option

java/src/org/openqa/selenium/grid/commands/Standalone.java

@@ -222,7 +222,7 @@ protected Handlers createHandlers(Config config) {
     httpHandler = combine(httpHandler, Route.get("/readyz").to(() -> readinessCheck));
     Node node = createNode(config, bus, distributor, combinedHandler);
 
-    return new Handlers(httpHandler, new ProxyNodeWebsockets(clientFactory, node));
+    return new Handlers(httpHandler, new ProxyNodeWebsockets(clientFactory, node, subPath));
   }
 
   @Override

java/src/org/openqa/selenium/grid/node/ProxyNodeWebsockets.java

@@ -56,18 +56,20 @@ public class ProxyNodeWebsockets
       ImmutableSet.of("goog:chromeOptions", "moz:debuggerAddress", "ms:edgeOptions");
   private final HttpClient.Factory clientFactory;
   private final Node node;
+  private final String gridSubPath;
 
-  public ProxyNodeWebsockets(HttpClient.Factory clientFactory, Node node) {
+  public ProxyNodeWebsockets(HttpClient.Factory clientFactory, Node node, String gridSubPath) {
     this.clientFactory = Objects.requireNonNull(clientFactory);
     this.node = Objects.requireNonNull(node);
+    this.gridSubPath = gridSubPath;
   }
 
   @Override
   public Optional<Consumer<Message>> apply(String uri, Consumer<Message> downstream) {
-    UrlTemplate.Match fwdMatch = FWD_TEMPLATE.match(uri);
-    UrlTemplate.Match cdpMatch = CDP_TEMPLATE.match(uri);
-    UrlTemplate.Match bidiMatch = BIDI_TEMPLATE.match(uri);
-    UrlTemplate.Match vncMatch = VNC_TEMPLATE.match(uri);
+    UrlTemplate.Match fwdMatch = FWD_TEMPLATE.match(uri, gridSubPath);
+    UrlTemplate.Match cdpMatch = CDP_TEMPLATE.match(uri, gridSubPath);
+    UrlTemplate.Match bidiMatch = BIDI_TEMPLATE.match(uri, gridSubPath);
+    UrlTemplate.Match vncMatch = VNC_TEMPLATE.match(uri, gridSubPath);
 
     if (bidiMatch == null && cdpMatch == null && vncMatch == null && fwdMatch == null) {
       return Optional.empty();

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

@@ -162,6 +162,21 @@ public boolean isManagedDownloadsEnabled() {
     return config.getBool(NODE_SECTION, "enable-managed-downloads").orElse(Boolean.FALSE);
   }
 
+  public String getGridSubPath() {
+    return normalizeSubPath(getPublicGridUri().map(URI::getPath).orElse(""));
+  }
+
+  public static String normalizeSubPath(String prefix) {
+    prefix = prefix.trim();
+    if (!prefix.startsWith("/")) {
+      prefix = "/" + prefix; // Prefix with a '/' if absent.
+    }
+    if (prefix.endsWith("/")) {
+      prefix = prefix.substring(0, prefix.length() - 1); // Remove the trailing '/' if present.
+    }
+    return prefix;
+  }
+
   public Node getNode() {
     return config.getClass(NODE_SECTION, "implementation", Node.class, DEFAULT_NODE_IMPLEMENTATION);
   }

java/src/org/openqa/selenium/grid/node/httpd/NodeServer.java

@@ -171,7 +171,8 @@ protected Handlers createHandlers(Config config) {
 
     Route httpHandler = Route.combine(node, get("/readyz").to(() -> readinessCheck));
 
-    return new Handlers(httpHandler, new ProxyNodeWebsockets(clientFactory, node));
+    return new Handlers(
+        httpHandler, new ProxyNodeWebsockets(clientFactory, node, nodeOptions.getGridSubPath()));
   }
 
   @Override

java/src/org/openqa/selenium/grid/node/local/LocalNode.java

@@ -838,9 +838,7 @@ private Session createExternalSession(
   private URI rewrite(String path) {
     try {
       String scheme = "https".equals(gridUri.getScheme()) ? "wss" : "ws";
-      if (gridUri.getPath() != null && !gridUri.getPath().equals("/")) {
-        path = gridUri.getPath() + path;
-      }
+      path = NodeOptions.normalizeSubPath(gridUri.getPath()) + path;
       return new URI(
           scheme, gridUri.getUserInfo(), gridUri.getHost(), gridUri.getPort(), path, null, null);
     } catch (URISyntaxException e) {

java/src/org/openqa/selenium/remote/http/UrlTemplate.java

@@ -139,6 +139,20 @@ public UrlTemplate.Match match(String matchAgainst) {
     return compiled.apply(matchAgainst);
   }
 
+  /**
+   * @return A {@link Match} with all parameters filled if successful, null otherwise. Remove
+   *     subPath from matchAgainst before matching.
+   */
+  public UrlTemplate.Match match(String matchAgainst, String prefix) {
+    if (matchAgainst == null || prefix == null) {
+      return null;
+    }
+    if (!prefix.isEmpty() && !prefix.equals("/")) {
+      matchAgainst = matchAgainst.replaceFirst(prefix, "");
+    }
+    return match(matchAgainst);
+  }
+
   @SuppressWarnings("InnerClassMayBeStatic")
   public class Match {
     private final String url;

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

@@ -673,6 +673,28 @@ void settingTheHubWithDefaultValueSetsTheGridUrlToTheNonLoopbackAddress() {
         .isEqualTo(Optional.of(URI.create(nonLoopbackAddressUrl)));
   }
 
+  @Test
+  void settingSubPathForNodeServerExtractFromGridUrl() {
+    String[] rawConfig =
+        new String[] {
+          "[node]", "grid-url = \"http://localhost:4444/mySubPath\"",
+        };
+    Config config = new TomlConfig(new StringReader(String.join("\n", rawConfig)));
+    NodeOptions nodeOptions = new NodeOptions(config);
+    assertThat(nodeOptions.getGridSubPath()).isEqualTo("/mySubPath");
+  }
+
+  @Test
+  void settingSubPathForNodeServerExtractFromHub() {
+    String[] rawConfig =
+        new String[] {
+          "[node]", "hub = \"http://0.0.0.0:4444/mySubPath\"",
+        };
+    Config config = new TomlConfig(new StringReader(String.join("\n", rawConfig)));
+    NodeOptions nodeOptions = new NodeOptions(config);
+    assertThat(nodeOptions.getGridSubPath()).isEqualTo("/mySubPath");
+  }
+
   @Test
   void notSettingSlotMatcherAvailable() {
     String[] rawConfig =

java/test/org/openqa/selenium/remote/http/UrlTemplateTest.java

@@ -67,6 +67,24 @@ void itIsFineForTheFirstCharacterToBeAPattern() {
     assertThat(match.getParameters()).isEqualTo(ImmutableMap.of("cake", "cheese"));
   }
 
+  @Test
+  void shouldMatchAgainstUrlTemplateExcludePrefix() {
+    UrlTemplate.Match match =
+        new UrlTemplate("/session/{id}/se/vnc").match("/prefix/session/1234/se/vnc", "/prefix");
+
+    assertThat(match.getUrl()).isEqualTo("/session/1234/se/vnc");
+    assertThat(match.getParameters()).isEqualTo(ImmutableMap.of("id", "1234"));
+  }
+
+  @Test
+  void shouldMatchAgainstUrlTemplateWithEmptyPrefix() {
+    UrlTemplate.Match match =
+        new UrlTemplate("/session/{id}/se/vnc").match("/session/1234/se/vnc", "");
+
+    assertThat(match.getUrl()).isEqualTo("/session/1234/se/vnc");
+    assertThat(match.getParameters()).isEqualTo(ImmutableMap.of("id", "1234"));
+  }
+
   @Test
   void aNullMatchDoesNotCauseANullPointerExceptionToBeThrown() {
     assertThat(new UrlTemplate("/").match(null)).isNull();