[#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/controllers/UniverseControllerTest.java

@@ -21,6 +21,7 @@
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.notNullValue;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertThat;
@@ -2321,4 +2322,28 @@ public void testRemoveEnclosingDoubleQuotes() {
     // Null string
     assertEquals(null, UniverseController.removeEnclosingDoubleQuotes(null));
   }
+
+  @Test
+  public void testClearNodeDetails() {
+    Provider p = ModelFactory.newProvider(customer, CloudType.onprem);
+    Region r = Region.create(p, "region-1", "PlacementRegion 1", "default-image");
+    AvailabilityZone az1 = AvailabilityZone.create(r, "az-1", "PlacementAZ 1", "subnet-1");
+    List<AvailabilityZone> azList = new ArrayList<AvailabilityZone>();
+    azList.add(az1);
+    UniverseDefinitionTaskParams taskParams = setupOnPremTestData(2, p, r, azList);
+
+    List<NodeInstance> nodeInstances = NodeInstance.listByProvider(p.uuid);
+    for (NodeInstance node : nodeInstances) {
+      node.setNodeName("TestUniverse");
+      node.inUse = true;
+      node.save();
+    }
+    for (NodeInstance node : nodeInstances) {
+      node.clearNodeDetails();
+    }
+    for (NodeInstance node : nodeInstances) {
+      assertFalse(node.inUse);
+      assertEquals("", node.getNodeName());
+    }
+  }
 }