added a DNS-multicast discovery support.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@31053 71c3de6d-444a-0410-be80-ed276b4c234a

core/pom.xml

@@ -700,6 +700,11 @@ THE SOFTWARE.
       <artifactId>wstx-asl</artifactId>
       <version>3.2.7</version>
     </dependency>
+    <dependency>
+      <groupId>org.jvnet.hudson</groupId>
+      <artifactId>jmdns</artifactId>
+      <version>3.1.6</version>
+    </dependency>
     <dependency>
       <groupId>com.sun.winsw</groupId>
       <artifactId>winsw</artifactId>

core/src/main/java/hudson/DNSMultiCast.java

+package hudson;
+
+import hudson.model.Hudson;
+
+import javax.jmdns.JmDNS;
+import javax.jmdns.ServiceInfo;
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Registers a DNS multi-cast service-discovery support.
+ *
+ * @author Kohsuke Kawaguchi
+ */
+public class DNSMultiCast implements Closeable {
+    private JmDNS jmdns;
+
+    public DNSMultiCast(Hudson hudson) {
+        try {
+            this.jmdns = JmDNS.create();
+
+            Map<String,String> props = new HashMap<String, String>();
+            props.put("url",hudson.getRootUrl());
+            props.put("version",Hudson.getVersion().toString());
+
+            TcpSlaveAgentListener tal = hudson.getTcpSlaveAgentListener();
+            if (tal!=null)
+                props.put("slave-port",String.valueOf(tal.getPort()));
+
+            jmdns.registerService(ServiceInfo.create("_hudson._tcp.local.","hudson",
+                    80,0,0,props));
+        } catch (IOException e) {
+            LOGGER.log(Level.WARNING,"Failed to advertise the service to DNS multi-cast",e);
+        }
+    }
+
+    public void close() {
+        jmdns.close();
+    }
+
+    private static final Logger LOGGER = Logger.getLogger(DNSMultiCast.class.getName());
+}

core/src/main/java/hudson/model/Hudson.java

@@ -26,6 +26,7 @@ package hudson.model;
 
 import com.thoughtworks.xstream.XStream;
 import hudson.BulkChange;
+import hudson.DNSMultiCast;
 import hudson.DescriptorExtensionList;
 import hudson.Extension;
 import hudson.ExtensionList;
@@ -422,6 +423,8 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
 
     private transient UDPBroadcastThread udpBroadcastThread;
 
+    private transient DNSMultiCast dnsMultiCast;
+
     /**
      * List of registered {@link ItemListener}s.
      * @deprecated as of 1.286
@@ -622,6 +625,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
 
             udpBroadcastThread = new UDPBroadcastThread(this);
             udpBroadcastThread.start();
+            dnsMultiCast = new DNSMultiCast(this);
 
             updateComputerList();
 
@@ -2198,6 +2202,8 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
         }
         if(udpBroadcastThread!=null)
             udpBroadcastThread.shutdown();
+        if(dnsMultiCast!=null)
+            dnsMultiCast.close();
         ExternalJob.reloadThread.interrupt();
         Trigger.timer.cancel();
         // TODO: how to wait for the completion of the last job?