extract code and add unit tests

Author: Pearl1594

plugins/integrations/kubernetes-service/src/main/java/com/cloud/kubernetes/cluster/actionworkers/KubernetesClusterScaleWorker.java

@@ -441,24 +441,30 @@ private void scaleDownKubernetesClusterSize() throws CloudRuntimeException {
         if (this.nodeIds != null) {
             vmList = getKubernetesClusterVMMapsForNodes(this.nodeIds).stream().filter(vm -> !vm.isExternalNode()).collect(Collectors.toList());
         } else {
-            List<KubernetesClusterVmMapVO> workerVMsMap  = getKubernetesClusterVMMaps().stream()
-                        .filter(vm -> !vm.isExternalNode() && !vm.isControlNode() && !vm.isEtcdNode())
-                        .collect(Collectors.toList());
-            int totalWorkerNodes = workerVMsMap.size();
-            int desiredWorkerNodes = clusterSize == null ? (int) kubernetesCluster.getNodeCount() : clusterSize.intValue();
-            int toRemoveCount = Math.max(0, totalWorkerNodes - desiredWorkerNodes);
-            if (toRemoveCount == 0) {
+            vmList = getWorkerNodesToRemove();
+            if (vmList.isEmpty()) {
                 logger.info("No nodes to remove from Kubernetes cluster: {}", kubernetesCluster);
                 return;
             }
-
-            int startIndex = Math.max(0, totalWorkerNodes - toRemoveCount);
-            vmList = new ArrayList<>(workerVMsMap.subList(startIndex, totalWorkerNodes));
         }
         Collections.reverse(vmList);
         removeNodesFromCluster(vmList);
     }
 
+    public List<KubernetesClusterVmMapVO> getWorkerNodesToRemove() {
+        List<KubernetesClusterVmMapVO> workerVMsMap = getKubernetesClusterVMMaps().stream()
+                .filter(vm -> !vm.isExternalNode() && !vm.isControlNode() && !vm.isEtcdNode())
+                .collect(Collectors.toList());
+        int totalWorkerNodes = workerVMsMap.size();
+        int desiredWorkerNodes = clusterSize == null ? (int) kubernetesCluster.getNodeCount() : clusterSize.intValue();
+        int toRemoveCount = Math.max(0, totalWorkerNodes - desiredWorkerNodes);
+        if (toRemoveCount == 0) {
+            return new ArrayList<>();
+        }
+        int startIndex = Math.max(0, totalWorkerNodes - toRemoveCount);
+        return new ArrayList<>(workerVMsMap.subList(startIndex, totalWorkerNodes));
+    }
+
     private void scaleUpKubernetesClusterSize(final long newVmCount) throws CloudRuntimeException {
         if (!kubernetesCluster.getState().equals(KubernetesCluster.State.Scaling)) {
             stateTransitTo(kubernetesCluster.getId(), KubernetesCluster.Event.ScaleUpRequested);

plugins/integrations/kubernetes-service/src/test/java/com/cloud/kubernetes/cluster/actionworkers/KubernetesClusterScaleWorkerTest.java

@@ -17,8 +17,8 @@
 package com.cloud.kubernetes.cluster.actionworkers;
 
 import com.cloud.kubernetes.cluster.KubernetesCluster;
-import com.cloud.kubernetes.cluster.KubernetesClusterManagerImpl;
 import com.cloud.kubernetes.cluster.KubernetesClusterVmMapVO;
+import com.cloud.kubernetes.cluster.KubernetesClusterManagerImpl;
 import com.cloud.kubernetes.cluster.dao.KubernetesClusterVmMapDao;
 import com.cloud.offering.ServiceOffering;
 import com.cloud.service.ServiceOfferingVO;
@@ -29,15 +29,17 @@
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
+
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.junit.MockitoJUnitRunner;
 
+import java.util.Arrays;
 import java.util.List;
 
-import static com.cloud.kubernetes.cluster.KubernetesServiceHelper.KubernetesClusterNodeType.DEFAULT;
 import static com.cloud.kubernetes.cluster.KubernetesServiceHelper.KubernetesClusterNodeType.CONTROL;
+import static com.cloud.kubernetes.cluster.KubernetesServiceHelper.KubernetesClusterNodeType.DEFAULT;
 
 @RunWith(MockitoJUnitRunner.class)
 public class KubernetesClusterScaleWorkerTest {
@@ -125,4 +127,64 @@ public void testCalculateNewClusterCountAndCapacityNodeTypeScaleControlOffering(
         Assert.assertEquals(expectedCores, newClusterCapacity.first().longValue());
         Assert.assertEquals(expectedMemory, newClusterCapacity.second().longValue());
     }
+
+
+    @Test
+    public void testGetWorkerNodesToRemoveForDownsize_singleRemoval() {
+        KubernetesCluster kubernetesCluster = Mockito.mock(KubernetesCluster.class);
+        KubernetesClusterManagerImpl clusterManager = Mockito.mock(KubernetesClusterManagerImpl.class);
+        KubernetesClusterScaleWorker worker = new KubernetesClusterScaleWorker(kubernetesCluster, new java.util.HashMap<>(), 2L, null, false, null, null, clusterManager);
+        KubernetesClusterScaleWorker spyWorker = Mockito.spy(worker);
+
+        KubernetesClusterVmMapVO vm1 = Mockito.mock(KubernetesClusterVmMapVO.class);
+        Mockito.when(vm1.isExternalNode()).thenReturn(false);
+        Mockito.when(vm1.isControlNode()).thenReturn(false);
+        Mockito.when(vm1.isEtcdNode()).thenReturn(false);
+
+        KubernetesClusterVmMapVO vm2 = Mockito.mock(KubernetesClusterVmMapVO.class);
+        Mockito.when(vm2.isExternalNode()).thenReturn(false);
+        Mockito.when(vm2.isControlNode()).thenReturn(false);
+        Mockito.when(vm2.isEtcdNode()).thenReturn(false);
+
+        KubernetesClusterVmMapVO vm3 = Mockito.mock(KubernetesClusterVmMapVO.class);
+        Mockito.when(vm3.isExternalNode()).thenReturn(false);
+        Mockito.when(vm3.isControlNode()).thenReturn(false);
+        Mockito.when(vm3.isEtcdNode()).thenReturn(false);
+
+        Mockito.doReturn(Arrays.asList(vm1, vm2, vm3)).when(spyWorker).getKubernetesClusterVMMaps();
+
+        List<KubernetesClusterVmMapVO> toRemove = spyWorker.getWorkerNodesToRemove();
+
+        Assert.assertEquals(1, toRemove.size());
+        Assert.assertSame(vm3, toRemove.get(0));
+    }
+
+    @Test
+    public void testGetWorkerNodesToRemoveForDownsize_noRemoval() {
+        KubernetesCluster kubernetesCluster = Mockito.mock(KubernetesCluster.class);
+
+        KubernetesClusterScaleWorker worker = new KubernetesClusterScaleWorker(kubernetesCluster, new java.util.HashMap<>(), 3L, null, false, null, null, clusterManager);
+        KubernetesClusterScaleWorker spyWorker = Mockito.spy(worker);
+
+        KubernetesClusterVmMapVO vm1 = Mockito.mock(KubernetesClusterVmMapVO.class);
+        Mockito.when(vm1.isExternalNode()).thenReturn(false);
+        Mockito.when(vm1.isControlNode()).thenReturn(false);
+        Mockito.when(vm1.isEtcdNode()).thenReturn(false);
+
+        KubernetesClusterVmMapVO vm2 = Mockito.mock(KubernetesClusterVmMapVO.class);
+        Mockito.when(vm2.isExternalNode()).thenReturn(false);
+        Mockito.when(vm2.isControlNode()).thenReturn(false);
+        Mockito.when(vm2.isEtcdNode()).thenReturn(false);
+
+        KubernetesClusterVmMapVO vm3 = Mockito.mock(KubernetesClusterVmMapVO.class);
+        Mockito.when(vm3.isExternalNode()).thenReturn(false);
+        Mockito.when(vm3.isControlNode()).thenReturn(false);
+        Mockito.when(vm3.isEtcdNode()).thenReturn(false);
+
+        Mockito.doReturn(Arrays.asList(vm1, vm2, vm3)).when(spyWorker).getKubernetesClusterVMMaps();
+
+        List<KubernetesClusterVmMapVO> toRemove = spyWorker.getWorkerNodesToRemove();
+
+        Assert.assertTrue(toRemove.isEmpty());
+    }
 }