Merge pull request #1668 from jenkinsci/dont-send-excessive-classes

[JENKINS-28058] Don't send a reference to Computer.class over remoting channels

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

@@ -1155,11 +1155,11 @@ public /*transient*/ abstract class Computer extends Actionable implements Acces
             try {
                 InetAddress ia = InetAddress.getByName(address);
                 if(!(ia instanceof Inet4Address)) {
-                    LOGGER.fine(address+" is not an IPv4 address");
+                    LOGGER.log(Level.FINE, "{0} is not an IPv4 address", address);
                     continue;
                 }
                 if(!ComputerPinger.checkIsReachable(ia, 3)) {
-                    LOGGER.fine(address+" didn't respond to ping");
+                    LOGGER.log(Level.FINE, "{0} didn't respond to ping", address);
                     continue;
                 }
                 cachedHostName = ia.getCanonicalHostName();
@@ -1167,7 +1167,10 @@ public /*transient*/ abstract class Computer extends Actionable implements Acces
                 return cachedHostName;
             } catch (IOException e) {
                 // if a given name fails to parse on this host, we get this error
-                LOGGER.log(Level.FINE, "Failed to parse "+address,e);
+                LogRecord lr = new LogRecord(Level.FINE, "Failed to parse {0}");
+                lr.setThrown(e);
+                lr.setParameters(new Object[]{address});
+                LOGGER.log(lr);
             }
         }
 
@@ -1191,27 +1194,38 @@ public /*transient*/ abstract class Computer extends Actionable implements Acces
     }
 
     private static class ListPossibleNames extends MasterToSlaveCallable<List<String>,IOException> {
+        /**
+         * In the normal case we would use {@link Computer} as the logger's name, however to
+         * do that we would have to send the {@link Computer} class over to the remote classloader
+         * and then it would need to be loaded, which pulls in {@link Jenkins} and loads that
+         * and then that fails to load as you are not supposed to do that. Another option
+         * would be to export the logger over remoting, with increased complexity as a result.
+         * Instead we just use a loger based on this class name and prevent any references to
+         * other classes from being transferred over remoting.
+         */
+        private static final Logger LOGGER = Logger.getLogger(ListPossibleNames.class.getName());
+        
         public List<String> call() throws IOException {
             List<String> names = new ArrayList<String>();
 
             Enumeration<NetworkInterface> nis = NetworkInterface.getNetworkInterfaces();
             while (nis.hasMoreElements()) {
                 NetworkInterface ni =  nis.nextElement();
-                LOGGER.fine("Listing up IP addresses for "+ni.getDisplayName());
+                LOGGER.log(Level.FINE, "Listing up IP addresses for {0}", ni.getDisplayName());
                 Enumeration<InetAddress> e = ni.getInetAddresses();
                 while (e.hasMoreElements()) {
                     InetAddress ia =  e.nextElement();
                     if(ia.isLoopbackAddress()) {
-                        LOGGER.fine(ia+" is a loopback address");
+                        LOGGER.log(Level.FINE, "{0} is a loopback address", ia);
                         continue;
                     }
 
                     if(!(ia instanceof Inet4Address)) {
-                        LOGGER.fine(ia+" is not an IPv4 address");
+                        LOGGER.log(Level.FINE, "{0} is not an IPv4 address", ia);
                         continue;
                     }
 
-                    LOGGER.fine(ia+" is a viable candidate");
+                    LOGGER.log(Level.FINE, "{0} is a viable candidate", ia);
                     names.add(ia.getHostAddress());
                 }
             }