Pull image version from metadata file

photon-core/src/main/java/org/photonvision/common/hardware/OsImageVersion.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) Photon Vision.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.photonvision.common.hardware;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Optional;
+import org.photonvision.common.logging.LogGroup;
+import org.photonvision.common.logging.Logger;
+
+/**
+ * Our blessed images inject the current version via this build workflow:
+ * https://github.com/PhotonVision/photon-image-modifier/blob/2e5ddb6b599df0be921c12c8dbe7b939ecd7f615/.github/workflows/main.yml#L67
+ *
+ * <p>This class provides a convienent abstraction around this
+ */
+public class OsImageVersion {
+    private static final Logger logger = new Logger(OsImageVersion.class, LogGroup.General);
+
+    private static Path imageVersionFile = Path.of("/opt/photonvision/image-version");
+
+    public static final Optional<String> IMAGE_VERSION = getImageVersion();
+
+    private static Optional<String> getImageVersion() {
+        if (!imageVersionFile.toFile().exists()) {
+            logger.warn(
+                    "Photon cannot locate base OS image version metadata at " + imageVersionFile.toString());
+            return Optional.empty();
+        }
+
+        try {
+            return Optional.of(Files.readString(imageVersionFile).strip());
+        } catch (IOException e) {
+            logger.error("Couldn't read image-version file", e);
+        }
+
+        return Optional.empty();
+    }
+}

photon-server/src/main/java/org/photonvision/Main.java

@@ -31,6 +31,7 @@
 import org.photonvision.common.configuration.NeuralNetworkModelManager;
 import org.photonvision.common.dataflow.networktables.NetworkTablesManager;
 import org.photonvision.common.hardware.HardwareManager;
+import org.photonvision.common.hardware.OsImageVersion;
 import org.photonvision.common.hardware.PiVersion;
 import org.photonvision.common.hardware.Platform;
 import org.photonvision.common.logging.KernelLogLogger;
@@ -353,10 +354,14 @@ public static void main(String[] args) {
         logger.info(
                 "Starting PhotonVision version "
                         + PhotonVersion.versionString
-                        + " on "
+                        + " on platform "
                         + Platform.getPlatformName()
                         + (Platform.isRaspberryPi() ? (" (Pi " + PiVersion.getPiVersion() + ")") : ""));
 
+        if (OsImageVersion.IMAGE_VERSION.isPresent()) {
+            logger.info("PhotonVision image version: " + OsImageVersion.IMAGE_VERSION.get());
+        }
+
         try {
             if (!handleArgs(args)) {
                 System.exit(1);