[#6758] Platform: Reuse on-premise instance once the instance got delete.

managed/src/main/java/com/yugabyte/yw/commissioner/tasks/UniverseTaskBase.java

@@ -32,6 +32,7 @@
 
 import com.yugabyte.yw.common.services.YBClientService;
 import com.yugabyte.yw.forms.UniverseTaskParams.EncryptionAtRestConfig.OpType;
+import com.yugabyte.yw.forms.UniverseDefinitionTaskParams.Cluster;
 import com.yugabyte.yw.models.Universe.UniverseUpdater;
 import com.yugabyte.yw.models.helpers.NodeDetails;
 import com.yugabyte.yw.models.helpers.TableDetails;
@@ -312,10 +313,20 @@ public SubTaskGroup createDestroyServerTasks(Collection<NodeDetails> nodes,
     SubTaskGroup subTaskGroup = new SubTaskGroup("AnsibleDestroyServers", executor);
     for (NodeDetails node : nodes) {
       // Check if the private ip for the node is set. If not, that means we don't have
-      // a clean state to delete the node. Log it and skip the node.
-      if (node.cloudInfo.private_ip == null) {
+      // a clean state to delete the node. Log it, free up the onprem node
+      // so that the client can use the node instance to create another universe.
+      if (node.cloudInfo.private_ip == null){
         LOG.warn(String.format("Node %s doesn't have a private IP. Skipping node delete.",
                                node.nodeName));
+        if (node.cloudInfo.cloud.equals(
+            com.yugabyte.yw.commissioner.Common.CloudType.onprem.name())) {
+          try {
+            NodeInstance providerNode = NodeInstance.getByName(node.nodeName);
+            providerNode.clearNodeDetails();
+          } catch (Exception ex) {
+            LOG.warn("On-prem node {} doesn't have a linked instance ", node.nodeName);
+          }
+        }
         continue;
       }
       AnsibleDestroyServer.Params params = new AnsibleDestroyServer.Params();

managed/src/test/java/com/yugabyte/yw/commissioner/tasks/UniverseTaskBaseTest.java

@@ -0,0 +1,107 @@
+// Copyright (c) YugaByte, Inc.
+
+package com.yugabyte.yw.commissioner.tasks;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import com.yugabyte.yw.commissioner.SubTaskGroupQueue;
+import com.yugabyte.yw.commissioner.Common.CloudType;
+import com.yugabyte.yw.common.FakeDBApplication;
+import com.yugabyte.yw.forms.NodeInstanceFormData.NodeInstanceData;
+import com.yugabyte.yw.forms.UniverseTaskParams;
+import com.yugabyte.yw.models.NodeInstance;
+import com.yugabyte.yw.models.helpers.CloudSpecificInfo;
+import com.yugabyte.yw.models.helpers.NodeDetails;
+
+import junitparams.JUnitParamsRunner;
+import junitparams.Parameters;
+import junitparams.converters.Nullable;
+
+@RunWith(JUnitParamsRunner.class)
+public class UniverseTaskBaseTest extends FakeDBApplication {
+
+    private static final int NUM_NODES = 3;
+    private TestUniverseTaskBase universeTaskBase = new TestUniverseTaskBase();
+
+    private List<NodeDetails> setupNodeDetails(CloudType cloudType, String privateIp) {
+        List<NodeDetails> nodes = new ArrayList<>();
+        for (int i = 0; i < NUM_NODES; i++) {
+            NodeDetails node = new NodeDetails();
+            node.nodeUuid = UUID.randomUUID();
+            node.azUuid = UUID.randomUUID();
+            node.nodeName = "node_" + String.valueOf(i);
+            node.cloudInfo = new CloudSpecificInfo();
+            node.cloudInfo.cloud = cloudType.name();
+            node.cloudInfo.private_ip = privateIp;
+
+            NodeInstance nodeInstance = new NodeInstance();
+            NodeInstanceData details = new NodeInstanceData();
+            details.instanceName = node.nodeName + "_instance";
+            details.ip = "ip";
+            details.nodeName = node.nodeName;
+            details.instanceType = "type";
+            details.zone = "zone";
+            nodeInstance.setDetails(details);
+            nodeInstance.setNodeName(node.nodeName);
+            nodeInstance.nodeUuid = node.nodeUuid;
+            nodeInstance.instanceName = details.instanceName;
+            nodeInstance.zoneUuid = node.azUuid;
+            nodeInstance.inUse = true;
+            nodeInstance.instanceTypeCode = details.instanceType;
+
+            nodeInstance.save();
+            nodes.add(node);
+        }
+        return nodes;
+    }
+
+    @Test
+    // @formatter:off
+    @Parameters({
+                 "aws, 1.1.1.1, false",    // aws with private IP
+                 "aws, null, false",       // aws without private IP
+                 "onprem, 1.1.1.1, false", // onprem with private IP
+                 "onprem, null, true"      // onprem without private IP
+                })
+    // @formatter:on
+    public void testCreateDestroyServerTasks(
+        CloudType cloudType, @Nullable String privateIp,boolean detailsCleanExpected) {
+
+        List<NodeDetails> nodes = setupNodeDetails(cloudType, privateIp);
+        universeTaskBase.createDestroyServerTasks(nodes, false, false);
+        for (int i = 0; i < NUM_NODES; i++) {
+            // Node should not be in use.
+            NodeInstance ni = NodeInstance.get(nodes.get(i).nodeUuid);
+            assertEquals(detailsCleanExpected, !ni.inUse);
+            // If the instance details are cleared then it is not possible to find it by node name
+            try {
+                NodeInstance nodeInstance =  NodeInstance.getByName(nodes.get(i).nodeName);
+                assertFalse(detailsCleanExpected);
+                assertTrue(nodeInstance.inUse);
+            } catch (Exception e) {
+                assertTrue(detailsCleanExpected);
+            }
+        }
+    }
+
+    private static class TestUniverseTaskBase extends UniverseTaskBase {
+
+        public TestUniverseTaskBase() {
+            super();
+            subTaskGroupQueue = new SubTaskGroupQueue(UUID.randomUUID());
+            taskParams = new UniverseTaskParams();
+        }
+
+        @Override
+        public void run() {}
+    }
+}