Add option to configure sending hostname

README.md

@@ -35,6 +35,7 @@ Add the following to your logback.xml configuration file.
             <graylog2ServerHost>localhost</graylog2ServerHost>
             <graylog2ServerPort>12201</graylog2ServerPort>
             <useLoggerName>true</useLoggerName>
+            <hostName>sendinghost</hostName>
             <useThreadName>true</useThreadName>
             <useMarker>true</useMarker>
             <graylog2ServerVersion>0.9.6</graylog2ServerVersion>
@@ -69,6 +70,7 @@ will be the name of the thread. Defaults to false;
 changed from 0.9.5 -> 0.9.6. Allowed values = 0.9.5 and 0.9.6. Defaults to "0.9.6"
 *   **chunkThreshold**: The maximum number of bytes allowed by the payload before the message should be chunked into
 smaller packets. Defaults to 1000
+*   **hostName** The hostname of the sending host. Defaults to getLocalHostName()
 *   **useMarker**: If true, and the user has used an slf4j marker (http://slf4j.org/api/org/slf4j/Marker.html) in their
 log message by using one of the marker-overloaded log methods (http://slf4j.org/api/org/slf4j/Logger.html), then the
 marker.toString() will be added to the gelf message as the field "_marker".  Defaults to false;

src/main/java/me/moocar/logbackgelf/GelfAppender.java

@@ -33,6 +33,7 @@ public class GelfAppender extends AppenderBase<ILoggingEvent> {
     private Map<String, String> additionalFields = new HashMap<String, String>();
     private Map<String, String> staticAdditionalFields = new HashMap<String, String>();
     private boolean includeFullMDC;
+    private String hostName;
 
     // The following are hidden (not configurable)
     private int shortMessageLength = 255;
@@ -93,14 +94,16 @@ private void initExecutor() {
                 padSeq = true;
             }
 
-            String hostname = getLocalHostName();
+            if (hostName == null) {
+                hostName = getLocalHostName();
+            }
 
             PayloadChunker payloadChunker = new PayloadChunker(chunkThreshold, maxChunks,
-                    new MessageIdProvider(messageIdLength, MessageDigest.getInstance("MD5"), hostname),
+                    new MessageIdProvider(messageIdLength, MessageDigest.getInstance("MD5"), hostName),
                     new ChunkFactory(chunkedGelfId, padSeq));
 
             GelfConverter converter = new GelfConverter(facility, useLoggerName, useThreadName, useMarker, additionalFields,
-                    staticAdditionalFields, shortMessageLength, hostname, messagePattern, shortMessagePattern,
+                    staticAdditionalFields, shortMessageLength, hostName, messagePattern, shortMessagePattern,
                     includeFullMDC);
 
             appenderExecutor = new AppenderExecutor(transport, payloadChunker, converter, new Zipper(), chunkThreshold);
@@ -234,6 +237,18 @@ public void setIncludeFullMDC(boolean includeFullMDC) {
         this.includeFullMDC = includeFullMDC;
     }
 
+    /**
+     * Override the local hostname using a config option
+     * @return the local hostname (defaults to getLocalHost() if not overridden
+     * in config
+     */
+    public String getHostName() {
+        return hostName;
+    }
+
+    public void setHostName(String hostName) {
+        this.hostName = hostName;
+    }
     /**
      * Add an additional field. This is mainly here for compatibility with logback.xml
      *

src/main/java/me/moocar/logbackgelf/GelfLayout.java

@@ -13,6 +13,7 @@ public class GelfLayout extends LayoutBase<ILoggingEvent> {
     // The following are configurable via logback configuration
     private String facility = "GELF";
     private boolean useLoggerName = false;
+    private String hostName;
     private boolean useThreadName = false;
     private boolean useMarker = false;
     private boolean appendLineSeparator = false;
@@ -60,6 +61,16 @@ public void setUseLoggerName(boolean useLoggerName) {
         this.useLoggerName = useLoggerName;
     }
 
+    public String getHostName()
+    {
+        return hostName;
+    }
+
+    public void setHostName(final String hostName)
+    {
+        this.hostName = hostName;
+    }
+
     public boolean isUseThreadName() {
         return useThreadName;
     }
@@ -146,7 +157,11 @@ public void start() {
 
     private void createConverter() {
         try {
-            this.converter = new GelfConverter(facility, useLoggerName, useThreadName, useMarker, additionalFields, staticAdditionalFields, shortMessageLength, getLocalHostName(), messagePattern, shortMessagePattern, includeFullMDC);
+            if (hostName == null) {
+                hostName = getLocalHostName();
+            }
+
+            this.converter = new GelfConverter(facility, useLoggerName, useThreadName, useMarker, additionalFields, staticAdditionalFields, shortMessageLength, hostName, messagePattern, shortMessagePattern, includeFullMDC);
         } catch (Exception e) {
             throw new RuntimeException("Unable to initialize converter", e);
         }

src/test/java/me/moocar/logbackgelf/IntegrationTest.java

@@ -50,7 +50,7 @@ private static String createLongMessage() {
     public void setup() throws SocketException, UnknownHostException {
         server = TestServer.build();
         server.start();
-        host = getLocalHostName();
+        host = "Test";
     }
 
     @Test
@@ -66,6 +66,7 @@ public void test() throws IOException, JoranException {
         assertMapEquals(makeMap(message), removeFields(lastRequest));
         assertTrue(lastRequest.containsKey("level"));
         assertTrue(lastRequest.containsKey("timestamp"));
+        assertTrue(lastRequest.containsKey("host"));
 
         // Test with IP and requestID in MDC
         ipAddress = "87.345.23.55";

src/test/resources/logback.xml

@@ -4,6 +4,7 @@
     <graylog2ServerHost>localhost</graylog2ServerHost>
     <graylog2ServerPort>12201</graylog2ServerPort>
     <useLoggerName>true</useLoggerName>
+    <hostName>Test</hostName>
     <graylog2ServerVersion>0.9.6</graylog2ServerVersion>
     <chunkThreshold>1000</chunkThreshold>
     <messagePattern>%m%rEx</messagePattern>

src/test/resources/staticAdditionalFields.xml

@@ -4,6 +4,7 @@
         <graylog2ServerHost>localhost</graylog2ServerHost>
         <graylog2ServerPort>12201</graylog2ServerPort>
         <useLoggerName>true</useLoggerName>
+        <hostName>Test</hostName>
         <graylog2ServerVersion>0.9.6</graylog2ServerVersion>
         <chunkThreshold>1000</chunkThreshold>
         <messagePattern>%m%rEx</messagePattern>