Add a basic syslog appender

This commits allows photonvision to push logs to a remote syslog
server such as the one on the roboRIO. To enable this on the RIO
create a file in /etc/syslog-ng.d/ for example

@Version: 3.8

source s_net { tcp(ip(0.0.0.0) port(514) max-connections (5000)); udp(); };
destination d_syslog { file("/var/log/remotelogs/syslog"); };

log { source(s_net); destination(d_syslog); };

This is experimental

photon-core/build.gradle

@@ -37,6 +37,9 @@ dependencies {
     // Zip
     implementation 'org.zeroturnaround:zt-zip:1.14'
 
+    // Syslog
+    implementation "com.cloudbees:syslog-java-client:1.1.7"
+
     implementation "org.xerial:sqlite-jdbc:3.41.0.0"
     implementation("org.photonvision:rknn_jni-jni:$rknnVersion:linuxarm64") {
         transitive = false

photon-core/src/main/java/org/photonvision/common/logging/Logger.java

@@ -29,6 +29,10 @@
 import org.photonvision.common.dataflow.DataChangeService;
 import org.photonvision.common.dataflow.events.OutgoingUIEvent;
 import org.photonvision.common.util.TimedTaskManager;
+import com.cloudbees.syslog.Facility;
+import com.cloudbees.syslog.MessageFormat;
+import com.cloudbees.syslog.Severity;
+import com.cloudbees.syslog.sender.UdpSyslogMessageSender;
 
 @SuppressWarnings("unused")
 public class Logger {
@@ -106,6 +110,7 @@ public static String format(
     static {
         currentAppenders.add(new ConsoleLogAppender());
         currentAppenders.add(uiLogAppender);
+        currentAppenders.add(new SyslogAppender("SomeCoprocessor", "172.22.11.2"));
         addFileAppender(PathManager.getInstance().getLogPath());
         cleanLogs(PathManager.getInstance().getLogsDir());
     }
@@ -314,6 +319,50 @@ public void log(String message, LogLevel level) {
         }
     }
 
+    private static class SyslogAppender implements LogAppender {
+        private UdpSyslogMessageSender messageSender = new UdpSyslogMessageSender();
+
+        private Severity ConvertLogLevel(LogLevel level) {
+            switch (level) {
+                case DEBUG:
+                    return Severity.DEBUG;
+                case ERROR:
+                    return Severity.ERROR;
+                case INFO:
+                    return Severity.INFORMATIONAL;
+                case TRACE:
+                    return Severity.DEBUG;
+                case WARN:
+                    return Severity.WARNING;
+                default:
+                    return Severity.INFORMATIONAL;
+            }
+        }
+
+        public SyslogAppender(String hostname, String ip) {
+            this(hostname, ip, 514);
+        }
+
+        public SyslogAppender(String hostname, String ip, int port) {
+            messageSender.setDefaultMessageHostname(hostname);
+            messageSender.setDefaultAppName("photonvision");
+            messageSender.setDefaultFacility(Facility.USER);
+            messageSender.setDefaultSeverity(Severity.INFORMATIONAL);
+            messageSender.setSyslogServerHostname(ip);
+            messageSender.setSyslogServerPort(port);
+            messageSender.setMessageFormat(MessageFormat.RFC_5424);
+        }
+
+        @Override
+        public void log(String message, LogLevel level) {
+            messageSender.setDefaultSeverity(ConvertLogLevel(level));
+            try {
+                messageSender.sendMessage(message);
+            } catch (IOException e) {
+            }
+        }
+    }
+
     private static class FileLogAppender implements LogAppender {
         private OutputStream out;
         private boolean wantsFlush;