From 1ee2ecb608b8e068971c704965b02aecc57627c0 Mon Sep 17 00:00:00 2001
From: Sam Freund <samf.236@proton.me>
Date: Sat, 11 Oct 2025 00:07:27 -0500
Subject: [PATCH] Make NT client name the same as hostname (#2107)

---
 .../networktables/NetworkTablesManager.java   | 16 ++++++++------
 .../common/networking/NetworkManager.java     | 21 ++++++++++++-------
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/photon-core/src/main/java/org/photonvision/common/dataflow/networktables/NetworkTablesManager.java b/photon-core/src/main/java/org/photonvision/common/dataflow/networktables/NetworkTablesManager.java
index 003b7d319..ba315afd0 100644
--- a/photon-core/src/main/java/org/photonvision/common/dataflow/networktables/NetworkTablesManager.java
+++ b/photon-core/src/main/java/org/photonvision/common/dataflow/networktables/NetworkTablesManager.java
@@ -18,6 +18,7 @@
 package org.photonvision.common.dataflow.networktables;
 
 import edu.wpi.first.apriltag.AprilTagFieldLayout;
+import edu.wpi.first.cscore.CameraServerJNI;
 import edu.wpi.first.networktables.LogMessage;
 import edu.wpi.first.networktables.MultiSubscriber;
 import edu.wpi.first.networktables.NetworkTable;
@@ -325,7 +326,7 @@ public class NetworkTablesManager {
         if (config.runNTServer) {
             setServerMode();
         } else {
-            setClientMode(config.ntServerAddress);
+            setClientMode(config);
         }
 
         m_timeSync.setConfig(config);
@@ -337,17 +338,20 @@ public class NetworkTablesManager {
         return m_timeSync.getOffset();
     }
 
-    private void setClientMode(String ntServerAddress) {
+    private void setClientMode(NetworkConfig config) {
         ntInstance.stopServer();
-        ntInstance.startClient4("photonvision");
+        ntInstance.stopClient();
+        String hostname = config.shouldManage ? config.hostname : CameraServerJNI.getHostname();
+        logger.debug("Starting NT Client with hostname: " + hostname);
+        ntInstance.startClient4(hostname);
         try {
-            int t = Integer.parseInt(ntServerAddress);
+            int t = Integer.parseInt(config.ntServerAddress);
             if (!m_isRetryingConnection) logger.info("Starting NT Client, server team is " + t);
             ntInstance.setServerTeam(t);
         } catch (NumberFormatException e) {
             if (!m_isRetryingConnection)
-                logger.info("Starting NT Client, server IP is \"" + ntServerAddress + "\"");
-            ntInstance.setServer(ntServerAddress);
+                logger.info("Starting NT Client, server IP is \"" + config.ntServerAddress + "\"");
+            ntInstance.setServer(config.ntServerAddress);
         }
         ntInstance.startDSClient();
         broadcastVersion();
diff --git a/photon-core/src/main/java/org/photonvision/common/networking/NetworkManager.java b/photon-core/src/main/java/org/photonvision/common/networking/NetworkManager.java
index 628346b74..8bde71ade 100644
--- a/photon-core/src/main/java/org/photonvision/common/networking/NetworkManager.java
+++ b/photon-core/src/main/java/org/photonvision/common/networking/NetworkManager.java
@@ -29,6 +29,7 @@ import org.photonvision.common.dataflow.DataChangeDestination;
 import org.photonvision.common.dataflow.DataChangeService;
 import org.photonvision.common.dataflow.DataChangeSource;
 import org.photonvision.common.dataflow.events.DataChangeEvent;
+import org.photonvision.common.dataflow.networktables.NetworkTablesManager;
 import org.photonvision.common.hardware.Platform;
 import org.photonvision.common.hardware.PlatformUtils;
 import org.photonvision.common.logging.LogGroup;
@@ -121,7 +122,7 @@ public class NetworkManager {
 
         // always set hostname (unless it's blank)
         if (!config.hostname.isBlank()) {
-            setHostname(config.hostname);
+            setHostname(config);
         } else {
             logger.warn("Got empty hostname?");
         }
@@ -145,29 +146,33 @@ public class NetworkManager {
                                 true));
     }
 
-    private void setHostname(String hostname) {
+    private void setHostname(NetworkConfig config) {
         try {
             var shell = new ShellExec(true, false);
             shell.executeBashCommand("cat /etc/hostname | tr -d \" \\t\\n\\r\"");
             var oldHostname = shell.getOutput().replace("\n", "");
             logger.debug("Old host name: \"" + oldHostname + "\"");
-            logger.debug("New host name: \"" + hostname + "\"");
+            logger.debug("New host name: \"" + config.hostname + "\"");
 
-            if (!oldHostname.equals(hostname)) {
+            if (!oldHostname.equals(config.hostname)) {
                 var setHostnameRetCode =
                         shell.executeBashCommand(
-                                "echo $NEW_HOSTNAME > /etc/hostname".replace("$NEW_HOSTNAME", hostname));
-                setHostnameRetCode = shell.executeBashCommand("hostnamectl set-hostname " + hostname);
+                                "echo $NEW_HOSTNAME > /etc/hostname".replace("$NEW_HOSTNAME", config.hostname));
+                setHostnameRetCode =
+                        shell.executeBashCommand("hostnamectl set-hostname " + config.hostname);
 
                 // Add to /etc/hosts
                 var addHostRetCode =
                         shell.executeBashCommand(
                                 String.format(
                                         "sed -i \"s/127.0.1.1.*%s/127.0.1.1\\t%s/g\" /etc/hosts",
-                                        oldHostname, hostname));
+                                        oldHostname, config.hostname));
 
                 shell.executeBashCommand("systemctl restart avahi-daemon.service");
 
+                // This resets the NetworkTables config to use the new hostname as the client ID
+                NetworkTablesManager.getInstance().setConfig(config);
+
                 var success = setHostnameRetCode == 0 && addHostRetCode == 0;
                 if (!success) {
                     logger.error(
@@ -177,7 +182,7 @@ public class NetworkManager {
                                     + addHostRetCode
                                     + "!");
                 } else {
-                    logger.info("Set hostname to " + hostname);
+                    logger.info("Set hostname to " + config.hostname);
                 }
             }
         } catch (Exception e) {