Force configuration update.

org.jdrupes.vmoperator.manager/src/org/jdrupes/vmoperator/manager/CmReconciler.java

@@ -20,13 +20,18 @@ package org.jdrupes.vmoperator.manager;
 
 import freemarker.template.Configuration;
 import freemarker.template.TemplateException;
+import io.kubernetes.client.custom.V1Patch;
+import io.kubernetes.client.openapi.ApiClient;
 import io.kubernetes.client.openapi.ApiException;
 import io.kubernetes.client.util.generic.dynamic.DynamicKubernetesApi;
 import io.kubernetes.client.util.generic.dynamic.DynamicKubernetesObject;
 import io.kubernetes.client.util.generic.dynamic.Dynamics;
+import io.kubernetes.client.util.generic.options.ListOptions;
+import io.kubernetes.client.util.generic.options.PatchOptions;
 import java.io.IOException;
 import java.io.StringWriter;
 import java.util.Map;
+import java.util.logging.Logger;
 import org.jdrupes.vmoperator.manager.VmDefChanged.Type;
 
 /**
@@ -35,6 +40,7 @@ import org.jdrupes.vmoperator.manager.VmDefChanged.Type;
 @SuppressWarnings("PMD.DataflowAnomalyAnalysis")
 /* default */ class CmReconciler {
 
+    protected final Logger logger = Logger.getLogger(getClass().getName());
     private final Configuration fmConfig;
 
     /**
@@ -81,8 +87,49 @@ import org.jdrupes.vmoperator.manager.VmDefChanged.Type;
         // https://github.com/kubernetes-client/java/issues/2741
         var mapDef = Dynamics.newFromYaml(out.toString());
 
-        // Apply
-        return K8s.apply(cmApi, mapDef, out.toString());
+        // Apply and maybe force pod update
+        var newState = K8s.apply(cmApi, mapDef, out.toString());
+        maybeForceUpdate(channel.client(), newState);
+        return newState;
+    }
+
+    /**
+     * Triggers update of config map mounted in pod
+     * See https://ahmet.im/blog/kubernetes-secret-volumes-delay/
+     * @param client 
+     * 
+     * @param newCm
+     */
+    private void maybeForceUpdate(ApiClient client,
+            DynamicKubernetesObject newCm) {
+        ListOptions listOpts = new ListOptions();
+        listOpts.setLabelSelector(
+            "app.kubernetes.io/managed-by=" + Constants.VM_OP_NAME + ","
+                + "app.kubernetes.io/name=" + Constants.APP_NAME);
+        // Get pod, selected by label
+        var podApi = new DynamicKubernetesApi("", "v1", "pods", client);
+        var pods = podApi
+            .list(newCm.getMetadata().getNamespace(), listOpts).getObject();
+        if (pods == null) {
+            return;
+        }
+        var pod = pods.getItems().get(0);
+
+        // Patch pod annotation
+        PatchOptions patchOpts = new PatchOptions();
+        patchOpts.setFieldManager("kubernetes-java-kubectl-apply");
+        var podMeta = pod.getMetadata();
+        var res = podApi.patch(podMeta.getNamespace(), podMeta.getName(),
+            V1Patch.PATCH_FORMAT_JSON_PATCH,
+            new V1Patch("[{\"op\": \"replace\", \"path\": "
+                + "\"/metadata/annotations/vmrunner.jdrupes.org~1cmVersion\", "
+                + "\"value\": \"" + newCm.getMetadata().getResourceVersion()
+                + "\"}]"),
+            patchOpts);
+        if (!res.isSuccess()) {
+            logger.warning(
+                () -> "Cannot patch pod annotations: " + res.getStatus());
+        }
     }
 
 }