From b9ddbf12ed9ea2e29e3d1b231d572cd5ae063574 Mon Sep 17 00:00:00 2001
From: sunxiaofei <sunxiaofei@xiaohongshu.com>
Date: Thu, 16 Feb 2023 20:20:38 +0800
Subject: [PATCH] fitsRequest check pod num

---
 pkg/descheduler/node/node.go      |  6 ++++
 pkg/descheduler/node/node_test.go | 59 +++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/pkg/descheduler/node/node.go b/pkg/descheduler/node/node.go
index bdf00eeb6..afa8fc1b8 100644
--- a/pkg/descheduler/node/node.go
+++ b/pkg/descheduler/node/node.go
@@ -222,6 +222,12 @@ func fitsRequest(nodeIndexer podutil.GetPodsAssignedToNodeFunc, pod *v1.Pod, nod
 			podFitsOnNode = false
 		}
 	}
+	// check pod num, at least one pod number is avaibalbe
+	if availableResources[v1.ResourcePods].MilliValue() <= 0 {
+		insufficientResources = append(insufficientResources, fmt.Errorf("insufficient %v", v1.ResourcePods))
+		podFitsOnNode = false
+	}
+
 	return podFitsOnNode, insufficientResources
 }
 
diff --git a/pkg/descheduler/node/node_test.go b/pkg/descheduler/node/node_test.go
index bd91fb511..18d4ec284 100644
--- a/pkg/descheduler/node/node_test.go
+++ b/pkg/descheduler/node/node_test.go
@@ -18,6 +18,7 @@ package node
 
 import (
 	"context"
+	"errors"
 	"testing"
 
 	v1 "k8s.io/api/core/v1"
@@ -752,6 +753,64 @@ func TestPodFitsAnyOtherNode(t *testing.T) {
 	}
 }
 
+func TestNodeFit(t *testing.T) {
+	node := test.BuildTestNode("node", 64000, 128*1000*1000*1000, 2, nil)
+	tests := []struct {
+		description string
+		pod         *v1.Pod
+		node        *v1.Node
+		podsOnNode  []*v1.Pod
+		err         error
+	}{
+		{
+			description: "insufficient cpu",
+			pod:         test.BuildTestPod("p1", 10000, 2*1000*1000*1000, "", nil),
+			node:        node,
+			podsOnNode: []*v1.Pod{
+				test.BuildTestPod("p2", 60000, 60*1000*1000*1000, "node", nil),
+			},
+			err: errors.New("insufficient cpu"),
+		},
+		{
+			description: "insufficient pod num",
+			pod:         test.BuildTestPod("p1", 1000, 2*1000*1000*1000, "", nil),
+			node:        node,
+			podsOnNode: []*v1.Pod{
+				test.BuildTestPod("p2", 1000, 2*1000*1000*1000, "node", nil),
+				test.BuildTestPod("p3", 1000, 2*1000*1000*1000, "node", nil),
+			},
+			err: errors.New("insufficient pods"),
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.description, func(t *testing.T) {
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+			objs := []runtime.Object{tc.node, tc.pod}
+			for _, pod := range tc.podsOnNode {
+				objs = append(objs, pod)
+			}
+
+			fakeClient := fake.NewSimpleClientset(objs...)
+
+			sharedInformerFactory := informers.NewSharedInformerFactory(fakeClient, 0)
+			podInformer := sharedInformerFactory.Core().V1().Pods().Informer()
+
+			getPodsAssignedToNode, err := podutil.BuildGetPodsAssignedToNodeFunc(podInformer)
+			if err != nil {
+				t.Errorf("Build get pods assigned to node function error: %v", err)
+			}
+
+			sharedInformerFactory.Start(ctx.Done())
+			sharedInformerFactory.WaitForCacheSync(ctx.Done())
+			if errs := NodeFit(getPodsAssignedToNode, tc.pod, tc.node); (len(errs) == 0 && tc.err != nil) || errs[0].Error() != tc.err.Error() {
+				t.Errorf("Test %#v failed, got %v, expect %v", tc.description, errs, tc.err)
+			}
+		})
+	}
+}
+
 // createResourceList builds a small resource list of core resources
 func createResourceList(cpu, memory, ephemeralStorage int64) v1.ResourceList {
 	resourceList := make(map[v1.ResourceName]resource.Quantity)