[grid] Implementing CORS support managed by --allow-cors option and adding support for OPTIONS requests to GraphqlHandler

Author: barancev

java/client/src/org/openqa/selenium/remote/http/HttpMethod.java

@@ -21,4 +21,5 @@ public enum HttpMethod {
   DELETE,
   GET,
   POST,
+  OPTIONS
 }

java/client/src/org/openqa/selenium/remote/http/Route.java

@@ -35,6 +35,7 @@
 import static org.openqa.selenium.remote.http.Contents.utf8String;
 import static org.openqa.selenium.remote.http.HttpMethod.DELETE;
 import static org.openqa.selenium.remote.http.HttpMethod.GET;
+import static org.openqa.selenium.remote.http.HttpMethod.OPTIONS;
 import static org.openqa.selenium.remote.http.HttpMethod.POST;
 import static org.openqa.selenium.remote.http.UrlPath.ROUTE_PREFIX_KEY;
 
@@ -111,6 +112,14 @@ public static TemplatizedRouteConfig post(String template) {
         urlTemplate);
   }
 
+  public static TemplatizedRouteConfig options(String template) {
+    UrlTemplate urlTemplate = new UrlTemplate(Require.nonNull("URL template", template));
+
+    return new TemplatizedRouteConfig(
+      new MatchesHttpMethod(OPTIONS).and(new MatchesTemplate(urlTemplate)),
+      urlTemplate);
+  }
+
   public static NestedRouteConfig prefix(String prefix) {
     Require.nonNull("Prefix", prefix);
     Require.stateCondition(!prefix.isEmpty(), "Prefix to use must not be of 0 length");

java/server/src/org/openqa/selenium/grid/commands/Hub.java

@@ -195,6 +195,7 @@ protected Handlers createHandlers(Config config) {
       ui,
       router.with(networkOptions.getSpecComplianceChecks()),
       Route.prefix("/wd/hub").to(combine(router.with(networkOptions.getSpecComplianceChecks()))),
+      Route.options("/graphql").to(() -> graphqlHandler),
       Route.post("/graphql").to(() -> graphqlHandler),
       Route.get("/readyz").to(() -> readinessCheck));
 

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

@@ -199,6 +199,7 @@ protected Handlers createHandlers(Config config) {
       ui,
       router,
       Route.prefix("/wd/hub").to(combine(router)),
+      Route.options("/graphql").to(() -> graphqlHandler),
       Route.post("/graphql").to(() -> graphqlHandler),
       Route.get("/readyz").to(() -> readinessCheck));
 

java/server/src/org/openqa/selenium/grid/graphql/GraphqlHandler.java

@@ -54,6 +54,7 @@
 import static org.openqa.selenium.json.Json.JSON_UTF_8;
 import static org.openqa.selenium.json.Json.MAP_TYPE;
 import static org.openqa.selenium.remote.http.Contents.utf8String;
+import static org.openqa.selenium.remote.http.HttpMethod.OPTIONS;
 import static org.openqa.selenium.remote.tracing.HttpTracing.newSpanAsChildOf;
 import static org.openqa.selenium.remote.tracing.Tags.HTTP_RESPONSE;
 import static org.openqa.selenium.remote.tracing.Tags.HTTP_RESPONSE_EVENT;
@@ -105,6 +106,9 @@ public GraphqlHandler(Tracer tracer, Distributor distributor, NewSessionQueuer n
 
   @Override
   public HttpResponse execute(HttpRequest req) throws UncheckedIOException {
+    if (req.getMethod() == OPTIONS) {
+      return new HttpResponse();
+    }
     try (Span span = newSpanAsChildOf(tracer, req, "grid.status")) {
       HttpResponse response;
       Map<String, Object> inputs = JSON.toType(Contents.string(req), MAP_TYPE);

java/server/src/org/openqa/selenium/grid/router/httpd/RouterServer.java

@@ -142,6 +142,7 @@ protected Handlers createHandlers(Config config) {
 
     Route handler = Route.combine(
       new Router(tracer, clientFactory, sessions, queuer, distributor).with(networkOptions.getSpecComplianceChecks()),
+      Route.options("/graphql").to(() -> graphqlHandler),
       Route.post("/graphql").to(() -> graphqlHandler),
       get("/readyz").to(() -> req -> new HttpResponse().setStatus(HTTP_NO_CONTENT)));
 

java/server/src/org/openqa/selenium/netty/server/NettyServer.java

@@ -57,6 +57,7 @@ public class NettyServer implements Server<NettyServer> {
   private final HttpHandler handler;
   private final BiFunction<String, Consumer<Message>, Optional<Consumer<Message>>> websocketHandler;
   private final SslContext sslCtx;
+  private final boolean allowCors;
 
   private Channel channel;
 
@@ -102,6 +103,7 @@ public NettyServer(
     workerGroup = new NioEventLoopGroup();
 
     port = options.getPort();
+    allowCors = options.getAllowCORS();
 
     try {
       externalUrl = options.getExternalUri().toURL();
@@ -142,7 +144,7 @@ public NettyServer start() {
     b.group(bossGroup, workerGroup)
       .channel(NioServerSocketChannel.class)
       .handler(new LoggingHandler(LogLevel.DEBUG))
-      .childHandler(new SeleniumHttpInitializer(sslCtx, handler, websocketHandler));
+      .childHandler(new SeleniumHttpInitializer(sslCtx, handler, websocketHandler, allowCors));
 
     try {
       channel = b.bind(port).sync().channel();

java/server/src/org/openqa/selenium/netty/server/ResponseConverter.java

@@ -40,6 +40,11 @@
 public class ResponseConverter extends ChannelOutboundHandlerAdapter {
 
   private static final int CHUNK_SIZE = 1024 * 1024;
+  private final boolean allowCors;
+
+  public ResponseConverter(boolean allowCors) {
+    this.allowCors = allowCors;
+  }
 
   @Override
   public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
@@ -100,5 +105,11 @@ private void copyHeaders(HttpResponse seResponse, DefaultHttpResponse first) {
         first.headers().add(name, value);
       }
     }
+
+    if (allowCors) {
+      first.headers().add("Access-Control-Allow-Origin", "*");
+      first.headers().add("Access-Control-Allow-Methods", "GET,POST,DELETE");
+      first.headers().add("Access-Control-Allow-Headers", "Accept,Content-Type");
+    }
   }
 }

java/server/src/org/openqa/selenium/netty/server/SeleniumHttpInitializer.java

@@ -40,14 +40,17 @@ class SeleniumHttpInitializer extends ChannelInitializer<SocketChannel> {
   private HttpHandler seleniumHandler;
   private final BiFunction<String, Consumer<Message>, Optional<Consumer<Message>>> webSocketHandler;
   private SslContext sslCtx;
+  private final boolean allowCors;
 
   SeleniumHttpInitializer(
     SslContext sslCtx,
     HttpHandler seleniumHandler,
-    BiFunction<String, Consumer<Message>, Optional<Consumer<Message>>> webSocketHandler) {
+    BiFunction<String, Consumer<Message>, Optional<Consumer<Message>>> webSocketHandler,
+    boolean allowCors) {
     this.sslCtx = sslCtx;
     this.seleniumHandler = Require.nonNull("HTTP handler", seleniumHandler);
     this.webSocketHandler = Require.nonNull("WebSocket handler", webSocketHandler);
+    this.allowCors = allowCors;
   }
 
   @Override
@@ -68,7 +71,7 @@ protected void initChannel(SocketChannel ch) {
 
     // Regular HTTP magic
     ch.pipeline().addLast("se-request", new RequestConverter());
-    ch.pipeline().addLast("se-response", new ResponseConverter());
+    ch.pipeline().addLast("se-response", new ResponseConverter(allowCors));
     ch.pipeline().addLast("se-handler", new SeleniumHandler(seleniumHandler));
   }
 }

javascript/grid-ui/src/config.ts

@@ -18,13 +18,9 @@ export const GridConfig = {
 	},
 
 	/** Server config */
-	// For development
-	// Install https://www.npmjs.com/package/cors-anywhere on an empty directory
-	// Run: node node_modules/cors-anywhere/server.js
-	// Then start the Selenium Server on port 4444 (which is the default).
 	serverUri:
 		process.env.NODE_ENV === "development"
-			? "http://localhost:8080/http://localhost:4444/graphql"
+			? "http://localhost:4444/graphql"
 			: document.location.protocol + "//" + document.location.host + "/graphql",
 
 	/** Keybinds config */