Merge pull request #431 from IABTechLab/ian-UID2-5188-check-if-pod-terminating

check if the pod is terminating in the healthcheck

Author: Ian-Nara

src/main/java/com/uid2/shared/health/HealthManager.java

@@ -1,5 +1,6 @@
 package com.uid2.shared.health;
 
+import java.io.File;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicReference;
@@ -22,6 +23,12 @@ public synchronized HealthComponent registerComponent(String name, boolean initi
         return component;
     }
 
+    public synchronized void registerGenericComponent(IHealthComponent component) {
+        List<IHealthComponent> newList = new ArrayList<IHealthComponent>(this.componentList.get());
+        newList.add(component);
+        this.componentList.set(newList);
+    }
+
     public boolean isHealthy() {
         // simple composite logic: service is healthy if none child component is unhealthy
         List<IHealthComponent> list = this.componentList.get();

src/main/java/com/uid2/shared/health/PodTerminationMonitor.java

@@ -0,0 +1,43 @@
+package com.uid2.shared.health;
+
+import java.io.File;
+import java.util.concurrent.atomic.AtomicReference;
+
+public class PodTerminationMonitor implements IHealthComponent{
+    private AtomicReference<Boolean> cachedPodTerminating = new AtomicReference<>(false);
+    private long lastPodCheckTime = 0;
+    private long fileCheckIntervalMs = 3000;
+
+
+    public PodTerminationMonitor() {}
+
+    public PodTerminationMonitor(long fileCheckIntervalMs) {
+        this.fileCheckIntervalMs = fileCheckIntervalMs;
+    }
+
+    @Override
+    public String name() {
+        return "PodTerminationMonitor";
+    }
+
+    @Override
+    public String reason() {
+        return checkPodTerminating() ? "Pod is terminating" : "";
+    }
+
+    @Override
+    public boolean isHealthy() {
+        return !checkPodTerminating();
+    }
+
+    private boolean checkPodTerminating() {
+        long currentTime = System.currentTimeMillis();
+        if (currentTime - lastPodCheckTime >= fileCheckIntervalMs) {
+            File file = new File(File.separator + "app" + File.separator + "pod_terminating");
+            boolean newStatus = file.exists();
+            cachedPodTerminating.set(newStatus);
+            lastPodCheckTime = currentTime;
+        }
+        return cachedPodTerminating.get();
+    }
+}