Enable forwarding of received syslog messaged.

build.gradle

@@ -4,7 +4,7 @@ plugins {
     id 'application'
     id "com.github.johnrengelman.shadow" version "6.1.0"
     id "net.nemerosa.versioning" version "2.14.0"
-    id "nebula.ospackage" version "8.4.1"
+    id "nebula.ospackage" version "8.4.2"
 }
 
 repositories {
@@ -12,10 +12,10 @@ repositories {
 }
 
 dependencies {
-    annotationProcessor 'info.picocli:picocli-codegen:4.6.0'
-    implementation 'info.picocli:picocli:4.6.0'
+    annotationProcessor 'info.picocli:picocli-codegen:4.6.1'
+    implementation 'info.picocli:picocli:4.6.1'
     implementation 'org.slf4j:slf4j-api:1.7.30'
-    runtimeOnly 'org.slf4j:slf4j-simple:1.7.30'
+    implementation 'org.slf4j:slf4j-simple:1.7.30'
 
     testImplementation('org.spockframework:spock-core:2.0-M4-groovy-3.0')
     testImplementation("org.slf4j:slf4j-simple:1.7.+")

gradle.properties

@@ -1,3 +1,3 @@
 id            = syslogd
 group         = biz.nellemann.syslogd
-version       = 1.0.7
+version       = 1.0.8

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.6.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

src/main/java/biz/nellemann/syslogd/Application.java

@@ -25,37 +25,48 @@ import java.util.concurrent.Callable;
 
 @Command(name = "syslogd",
         mixinStandardHelpOptions = true,
-        description = "Basic syslog server.",
+        description = "Syslog Daemon.",
         versionProvider = biz.nellemann.syslogd.VersionProvider.class)
 public class Application implements Callable<Integer>, LogListener {
 
     private final static Logger log = LoggerFactory.getLogger(Application.class);
 
-    @CommandLine.Option(names = {"-p", "--port"}, description = "Listening port [default: 514].")
-    private int port = 514;
+    @CommandLine.Option(names = {"-p", "--port"}, description = "Listening port [default: 514].", defaultValue = "514")
+    private int port;
 
-    @CommandLine.Option(names = "--no-udp", negatable = true, description = "Listen on UDP [default: true].")
-    boolean udpServer = true;
+    @CommandLine.Option(names = "--no-udp", negatable = true, description = "Listen on UDP [default: true].", defaultValue = "true")
+    private boolean udpServer;
 
-    @CommandLine.Option(names = "--no-tcp", negatable = true, description = "Listen on TCP [default: true].")
-    boolean tcpServer = true;
+    @CommandLine.Option(names = "--no-tcp", negatable = true, description = "Listen on TCP [default: true].", defaultValue = "true")
+    private boolean tcpServer;
 
-    @CommandLine.Option(names = "--no-ansi", negatable = true, description = "Output ANSI colors [default: true].")
-    boolean ansiOutput = true;
+    @CommandLine.Option(names = "--no-ansi", negatable = true, description = "Output ANSI colors [default: true].", defaultValue = "true")
+    private boolean ansiOutput;
 
-    @CommandLine.Option(names = "--rfc5424", description = "Parse RFC-5424 messages [default: RFC-3164].")
-    boolean rfc5424 = false;
+    @CommandLine.Option(names = "--no-stdout", negatable = true, description = "Output messages to stdout [default: true].", defaultValue = "true")
+    private boolean stdout;
 
+    @CommandLine.Option(names = "--rfc5424", description = "Parse RFC-5424 messages [default: RFC-3164].", defaultValue = "false")
+    private boolean rfc5424;
 
-    public static void main(String... args) {
-        int exitCode = new CommandLine(new Application()).execute(args);
-        System.exit(exitCode);
-    }
+    @CommandLine.Option(names = { "-f", "--forward"}, description = "Forward messages (UDP RFC-3164) [default: false].", defaultValue = "false")
+    private boolean forward;
 
+    @CommandLine.Option(names = "--forward-host", description = "Forward to host [default: localhost].", paramLabel = "<hostname>", defaultValue = "localhost")
+    private String forwardHost;
+
+    @CommandLine.Option(names = "--forward-port", description = "Forward to port [default: 1514].", paramLabel = "<port>", defaultValue = "1514")
+    private int forwardPort;
+
+    private UdpClient udpClient;
 
     @Override
     public Integer call() throws IOException {
 
+        if(forward) {
+            udpClient = new UdpClient(forwardHost, forwardPort);
+        }
+
         if(udpServer) {
             UdpServer udpServer = new UdpServer(port);
             udpServer.addEventListener(this);
@@ -85,17 +96,34 @@ public class Application implements Callable<Integer>, LogListener {
                 msg = SyslogParser.parseRfc3164(message);
             }
         } catch(Exception e) {
-            log.error("Problem parsing message: ", e);
+            log.error("onLogEvent() - Error parsing message: ", e);
         }
 
         if(msg != null) {
+
+            if(stdout) {
                 if(ansiOutput) {
-                System.out.println(msg.toAnsiString());
+                    System.out.println(SyslogPrinter.toAnsiString(msg));
                 } else {
-                System.out.println(msg);
+                    System.out.println(SyslogPrinter.toString(msg));
                 }
             }
 
+            if(forward) {
+                try {
+                    udpClient.send(SyslogPrinter.toRfc3164(msg));
+                } catch (Exception e) {
+                    log.error("onLogEvent()", e);
+                }
+            }
+        }
+
+    }
+
+
+    public static void main(String... args) {
+        int exitCode = new CommandLine(new Application()).execute(args);
+        System.exit(exitCode);
     }
 
 }

src/main/java/biz/nellemann/syslogd/SyslogMessage.java

@@ -50,38 +50,4 @@ public class SyslogMessage {
         this.message = message;
     }
 
-
-
-    public String toString() {
-        StringBuilder sb = new StringBuilder();
-        sb.append(timestamp.toString());
-        sb.append(String.format("  [%8.8s.%-6.6s] ", facility, severity));
-        sb.append(String.format(" %-16.16s ", hostname));
-        sb.append(String.format(" %-32.32s  ", application));
-        sb.append(message);
-        return sb.toString();
-    }
-
-
-    public String toAnsiString() {
-        StringBuilder sb = new StringBuilder();
-
-        sb.append(timestamp.toString());
-
-        if(severity.toNumber() < 3 ) {
-            sb.append(Ansi.RED);
-        } else if(severity.toNumber() < 5) {
-            sb.append(Ansi.YELLOW);
-        } else {
-            sb.append(Ansi.GREEN);
-        }
-
-        sb.append(String.format("  [%8.8s.%-6.6s] ", facility, severity)).append(Ansi.RESET);
-        sb.append(Ansi.BLUE).append(String.format(" %-16.16s ", hostname)).append(Ansi.RESET);
-        sb.append(Ansi.CYAN).append(String.format(" %-32.32s  ", application)).append(Ansi.RESET);
-        sb.append(message);
-
-        return sb.toString();
-    }
-
 }

src/main/java/biz/nellemann/syslogd/SyslogParser.java

@@ -197,4 +197,5 @@ public class SyslogParser {
         return severity;
     }
 
+
 }

src/main/java/biz/nellemann/syslogd/SyslogPrinter.java

@@ -0,0 +1,74 @@
+package biz.nellemann.syslogd;
+
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.ChronoUnit;
+
+public class SyslogPrinter {
+
+    public static String toString(SyslogMessage msg) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(msg.timestamp.toString());
+        sb.append(String.format("  [%8.8s.%-6.6s] ", msg.facility, msg.severity));
+        sb.append(String.format(" %-16.16s ", msg.hostname));
+        sb.append(String.format(" %-32.32s  ", msg.application));
+        sb.append(msg.message);
+        return sb.toString();
+    }
+
+
+    public static String toAnsiString(SyslogMessage msg) {
+        StringBuilder sb = new StringBuilder();
+
+        sb.append(msg.timestamp.toString());
+
+        if (msg.severity.toNumber() < 3) {
+            sb.append(Ansi.RED);
+        } else if (msg.severity.toNumber() < 5) {
+            sb.append(Ansi.YELLOW);
+        } else {
+            sb.append(Ansi.GREEN);
+        }
+
+        sb.append(String.format("  [%8.8s.%-6.6s] ", msg.facility, msg.severity)).append(Ansi.RESET);
+        sb.append(Ansi.BLUE).append(String.format(" %-16.16s ", msg.hostname)).append(Ansi.RESET);
+        sb.append(Ansi.CYAN).append(String.format(" %-32.32s  ", msg.application)).append(Ansi.RESET);
+        sb.append(msg.message);
+
+        return sb.toString();
+    }
+
+
+    // <13>Sep 23 08:53:28 xps13 mark: adfdfdf3432434
+    public static String toRfc3164(SyslogMessage msg) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(getPri(msg.facility, msg.severity));
+        sb.append(" " + new java.text.SimpleDateFormat("MMM dd HH:mm:ss").format(new java.util.Date(msg.timestamp.toEpochMilli())));
+        sb.append(" " + msg.hostname);
+        sb.append(" " + msg.application);
+        sb.append(": " + msg.message);
+
+        return sb.toString();
+    }
+
+
+    // <13>1 2020-09-23T08:57:30.950699+02:00 xps13 mark - - [timeQuality tzKnown="1" isSynced="1" syncAccuracy="125500"] adfdfdf3432434565656
+    public static String toRfc5424(SyslogMessage msg) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(getPri(msg.facility, msg.severity));
+        sb.append("1"); // Version
+        sb.append(" " + new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'").format(new java.util.Date(msg.timestamp.toEpochMilli())));
+        sb.append(" " + msg.hostname);
+        sb.append(" " + msg.application);
+        sb.append(": " + msg.message);
+
+        return sb.toString();
+    }
+
+
+    // TODO: Facility+Severity to PRI field
+    static private String getPri(Facility facility, Severity severity) {
+        return "<13>";
+    }
+
+
+}

src/main/java/biz/nellemann/syslogd/UdpClient.java

@@ -0,0 +1,30 @@
+package biz.nellemann.syslogd;
+
+import java.io.IOException;
+import java.net.*;
+
+public class UdpClient {
+
+    private DatagramSocket socket;
+    private InetAddress address;
+    private Integer port;
+
+    private byte[] buf;
+
+    public UdpClient(String host, Integer port) throws UnknownHostException, SocketException {
+        socket = new DatagramSocket();
+        address = InetAddress.getByName(host);
+        this.port = port;
+    }
+
+    public void send(String msg) throws IOException {
+        buf = msg.getBytes();
+        DatagramPacket packet
+            = new DatagramPacket(buf, buf.length, address, port);
+        socket.send(packet);
+    }
+
+    public void close() {
+        socket.close();
+    }
+}