Immediately shutdown standalone/hub/node if the port is busy with a human readable message

Author: barancev

java/server/src/org/openqa/grid/internal/utils/SelfRegisteringRemote.java

@@ -116,12 +116,12 @@ public void setRemoteServer(GridNodeServer server) {
     this.server = server;
   }
 
-  public void startRemoteServer() throws Exception {
+  public boolean startRemoteServer() throws Exception {
     if (server == null) {
       throw new GridConfigurationException("no server set to register to the hub");
     }
     server.setExtraServlets(nodeServlets);
-    server.boot();
+    return server.boot();
   }
 
   public void stopRemoteServer() {

java/server/src/org/openqa/grid/selenium/GridLauncherV3.java

@@ -229,13 +229,13 @@ public void setConfiguration(String[] args) {
           }
 
           public void launch() throws Exception {
-            log.info("Launching a standalone Selenium Server");
+            log.info(String.format(
+                "Launching a standalone Selenium Server on port %s", configuration.port));
             SeleniumServer server = new SeleniumServer(configuration);
             Map<String, Class<? extends Servlet >> servlets = new HashMap<>();
             servlets.put("/*", DisplayHelpServlet.class);
             server.setExtraServlets(servlets);
             server.boot();
-            log.info("Selenium Server is up and running");
           }
         })
         .put(GridRole.HUB.toString(), () -> new GridItemLauncher() {
@@ -256,11 +256,10 @@ public void setConfiguration(String[] args) {
           }
 
           public void launch() throws Exception {
-            log.info("Launching Selenium Grid hub");
+            log.info(String.format(
+                "Launching Selenium Grid hub on port %s", configuration.port));
             Hub h = new Hub(configuration);
             h.start();
-            log.info("Nodes should register to " + h.getRegistrationURL());
-            log.info("Selenium Grid hub is up and running");
           }
         })
         .put(GridRole.NODE.toString(), () -> new GridItemLauncher() {
@@ -284,12 +283,14 @@ public void setConfiguration(String[] args) {
           }
 
           public void launch() throws Exception {
-            log.info("Launching a Selenium Grid node");
+            log.info(String.format(
+                "Launching a Selenium Grid node on port %s", configuration.port));
             SelfRegisteringRemote remote = new SelfRegisteringRemote(configuration);
             remote.setRemoteServer(new SeleniumServer(remote.getConfiguration()));
-            remote.startRemoteServer();
-            log.info("Selenium Grid node is up and ready to register to the hub");
-            remote.startRegistrationProcess();
+            if (remote.startRemoteServer()) {
+              log.info("Selenium Grid node is up and ready to register to the hub");
+              remote.startRegistrationProcess();
+            }
           }
         });
 

java/server/src/org/openqa/grid/shared/GridNodeServer.java

@@ -24,7 +24,7 @@
 import javax.servlet.Servlet;
 
 public interface GridNodeServer {
-  void boot() throws Exception;
+  boolean boot() throws Exception;
   void stop();
   int getRealPort();
   void setExtraServlets(Map<String, Class<? extends Servlet>> extraServlets);

java/server/src/org/openqa/grid/web/Hub.java

@@ -47,6 +47,7 @@
 import org.seleniumhq.jetty9.servlet.ServletHolder;
 import org.seleniumhq.jetty9.util.thread.QueuedThreadPool;
 
+import java.net.BindException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.Map;
@@ -174,8 +175,6 @@ private void initServer() {
       httpConfig.setSecureScheme("https");
       httpConfig.setSecurePort(config.port);
 
-      log.info("Will listen on " + config.port);
-
       ServerConnector http = new ServerConnector(server, new HttpConnectionFactory(httpConfig));
       http.setPort(config.port);
 
@@ -211,7 +210,26 @@ public Map<?,?> getConfigurationForJMX() {
 
   public void start() throws Exception {
     initServer();
-    server.start();
+
+    try {
+      server.start();
+    } catch (Exception e) {
+      try {
+        stop();
+      } catch (Exception ignore) {
+      }
+      if (e instanceof BindException) {
+        log.severe(String.format(
+            "Port %s is busy, please choose a free port for the hub and specify it using -port option", config.port));
+        return;
+      } else {
+        throw new RuntimeException(e);
+      }
+    }
+
+    log.info("Selenium Grid hub is up and running");
+    log.info(String.format("Nodes should register to %s", getRegistrationURL()));
+    log.info(String.format("Clients should connect to %s", getWebDriverHubRequestURL()));
   }
 
   public void stop() throws Exception {

java/server/src/org/openqa/selenium/remote/server/SeleniumServer.java

@@ -45,6 +45,7 @@
 import org.seleniumhq.jetty9.util.security.Constraint;
 import org.seleniumhq.jetty9.util.thread.QueuedThreadPool;
 
+import java.net.BindException;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Logger;
@@ -121,7 +122,7 @@ public void setExtraServlets(Map<String, Class<? extends Servlet>> extraServlets
     this.extraServlets = extraServlets;
   }
 
-  public void boot() {
+  public boolean boot() {
     if (configuration.jettyMaxThreads != null && configuration.jettyMaxThreads > 0) {
       server = new Server(new QueuedThreadPool(configuration.jettyMaxThreads));
     } else {
@@ -195,8 +196,21 @@ public void boot() {
     try {
       server.start();
     } catch (Exception e) {
-      throw new RuntimeException(e);
+      try {
+        server.stop();
+      } catch (Exception ignore) {
+      }
+      if (e instanceof BindException) {
+        LOG.severe(String.format(
+            "Port %s is busy, please choose a free port and specify it using -port option", configuration.port));
+        return false;
+      } else {
+        throw new RuntimeException(e);
+      }
     }
+
+    LOG.info(String.format("Selenium Server is up and running on port %s", configuration.port));
+    return true;
   }
 
   private NewSessionPipeline createPipeline(StandaloneConfiguration configuration) {

java/server/test/org/openqa/grid/internal/utils/SelfRegisteringRemoteTest.java

@@ -39,7 +39,7 @@ private final class DummyGridNodeServer implements GridNodeServer {
     public Map<String, Class<? extends Servlet>> extraServlets;
 
     @Override
-    public void boot() throws Exception { }
+    public boolean boot() throws Exception { return true; }
 
     @Override
     public void stop() { }