added '/hostname' to the HealthResource, which is handy in a dockeriz…

src/main/java/com/airhacks/ping/boundary/HealthResource.java

@@ -44,4 +44,9 @@ public JsonObject osInfo() {
         return this.watch.osInfo();
     }
 
+    @GET
+    @Path("/hostname")
+    public String hostname() {
+        return this.watch.getHostname();
+    }
 }

src/main/java/com/airhacks/ping/control/ServerWatch.java

@@ -4,6 +4,8 @@
 import java.lang.management.MemoryMXBean;
 import java.lang.management.MemoryUsage;
 import java.lang.management.OperatingSystemMXBean;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
 import java.time.ZonedDateTime;
 import javax.annotation.PostConstruct;
 import javax.ejb.Singleton;
@@ -22,19 +24,32 @@ public class ServerWatch {
     private ZonedDateTime startTime;
     private MemoryUsage heapUsageAtStartTime;
     private MemoryMXBean memoryMxBean;
+    private String hostname;
 
     @PostConstruct
     public void initialize() {
         this.initializeStartTime();
         this.memoryMxBean = ManagementFactory.getMemoryMXBean();
         this.heapUsageAtStartTime = this.memoryMxBean.getHeapMemoryUsage();
-
+        this.lookupHostname();
     }
 
     void initializeStartTime() {
         this.startTime = ZonedDateTime.now();
     }
 
+    void lookupHostname() {
+        try {
+            this.hostname = InetAddress.getLocalHost().getHostName();
+        } catch (UnknownHostException ex) {
+            this.hostname = "<unknown> : " + ex.getMessage();
+        }
+    }
+
+    public String getHostname() {
+        return hostname;
+    }
+
     public ZonedDateTime getDateTime() {
         return this.startTime;
     }

src/main/webapp/index.html

@@ -41,6 +41,9 @@ <h2>Health</h2>
             <article>
                 <a href="./resources/health/os-info">Operating System Info</a>
             </article>
+            <article>
+                <a href="./resources/health/hostname">Hostname</a>
+            </article>
         </section>
     </body>
 </html>