Support optional cluster name in policy engine

This allows also for correlation with running pod hostnames
in the case of multiple drools pdp flavors coexist.

Issue-ID: POLICY-4403
Signed-off-by: jhh <jorge.hernandez-herrero@att.com>
Change-Id: I81affeeec622e6c0e9627651bf34c0775a796827
Signed-off-by: jhh <jorge.hernandez-herrero@att.com>

3 files changed, 43 insertions, 8 deletions

diff --git a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngine.java b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngine.java
index 10623c50..75e7c74a 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngine.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngine.java
@@ -2,7 +2,7 @@
  * ============LICENSE_START=======================================================
  * ONAP
  * ================================================================================
- * Copyright (C) 2017-2021 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2017-2022 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -122,6 +122,25 @@ public interface PolicyEngine extends Startable, Lockable, TopicListener {
     String setEnvironmentProperty(String key, String value);
 
     /**
+     * Gets the hostname used by this PDP-D.
+     */
+    String getHostName();
+
+    /**
+     * Gets the cluster name as configured in $CLUSTER_NAME,
+     * otherwise it will assume an UUID as the cluster name.
+     */
+    String getClusterName();
+
+    /**
+     * Gets the PDP Name from hostname and $CLUSTER_NAME,
+     * otherwise if CLUSTER_NAME is not set, the PdpName
+     * will be the concatenation of the hostname and a
+     * UUID.
+     */
+    String getPdpName();
+
+    /**
      * registers a new Policy Controller with the Policy Engine initialized per properties.
      *
      * @param properties properties to initialize the Policy Controller
diff --git a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineConstants.java b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineConstants.java
index 23fc247e..ffd0c858 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineConstants.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineConstants.java
@@ -2,7 +2,7 @@
  * ============LICENSE_START=======================================================
  * policy-management
  * ================================================================================
- * Copyright (C) 2019, 2021 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2019, 2021-2022 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -44,11 +44,6 @@ public final class PolicyEngineConstants {
     public static final String TELEMETRY_SERVER_DEFAULT_NAME = "TELEMETRY";
 
     /**
-     * Unique name of this drools-pdp JVM.
-     */
-    public static final String PDP_NAME = NetworkUtil.genUniqueName("drools");
-
-    /**
      * Policy Engine Manager.
      */
     @Getter
diff --git a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineManager.java b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineManager.java
index ea4094fc..19aec79a 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineManager.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/system/PolicyEngineManager.java
@@ -31,6 +31,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
 import java.util.Properties;
+import java.util.UUID;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.atomic.AtomicReference;
@@ -41,6 +42,8 @@ import java.util.stream.Stream;
 import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.NonNull;
+import lombok.Setter;
+import lombok.Synchronized;
 import lombok.ToString;
 import org.apache.commons.lang3.StringUtils;
 import org.onap.policy.common.endpoints.event.comm.Topic;
@@ -59,6 +62,7 @@ import org.onap.policy.common.endpoints.properties.PolicyEndPointProperties;
 import org.onap.policy.common.gson.annotation.GsonJsonIgnore;
 import org.onap.policy.common.gson.annotation.GsonJsonProperty;
 import org.onap.policy.common.utils.logging.LoggerUtils;
+import org.onap.policy.common.utils.network.NetworkUtil;
 import org.onap.policy.common.utils.resources.PrometheusUtils;
 import org.onap.policy.common.utils.services.FeatureApiUtils;
 import org.onap.policy.drools.controller.DroolsControllerConstants;
@@ -107,6 +111,8 @@ class PolicyEngineManager implements PolicyEngine {
     public static final String EXECUTOR_THREAD_PROP = "executor.threads";
     protected static final int DEFAULT_EXECUTOR_THREADS = 5;
 
+    public static final String CLUSTER_NAME_PROP = "engine.cluster";
+
     /**
      * logger.
      */
@@ -170,6 +176,18 @@ class PolicyEngineManager implements PolicyEngine {
     @Getter
     private final PolicyStatsManager stats = new PolicyStatsManager();
 
+    @Getter(onMethod_ = {@Synchronized}, value = AccessLevel.PUBLIC)
+    @Setter(onMethod_ = {@Synchronized}, value = AccessLevel.PUBLIC)
+    private String clusterName = UUID.randomUUID().toString();
+
+    @Getter(onMethod_ = {@Synchronized}, value = AccessLevel.PUBLIC)
+    @Setter(onMethod_ = {@Synchronized}, value = AccessLevel.PUBLIC)
+    private String hostName = NetworkUtil.getHostname();
+
+    @Getter(onMethod_ = {@Synchronized}, value = AccessLevel.PUBLIC)
+    @Setter(onMethod_ = {@Synchronized}, value = AccessLevel.PUBLIC)
+    private String pdpName;
+
     /**
      * gson parser to decode configuration requests.
      */
@@ -368,6 +386,10 @@ class PolicyEngineManager implements PolicyEngine {
         }
 
         this.properties = properties;
+        if (!StringUtils.isBlank(this.properties.getProperty(CLUSTER_NAME_PROP))) {
+            this.clusterName = this.properties.getProperty(CLUSTER_NAME_PROP, this.clusterName);
+        }
+        this.pdpName = hostName + "." + this.clusterName;
 
         try {
             this.sources = getTopicEndpointManager().addTopicSources(properties);
@@ -438,7 +460,6 @@ class PolicyEngineManager implements PolicyEngine {
 
     @Override
     public synchronized PolicyController createPolicyController(String name, Properties properties) {
-
         String tempName = name;
         // check if a PROPERTY_CONTROLLER_NAME property is present
         // if so, override the given name