Enable PodAffinity by default in scheduler

plugin/pkg/scheduler/algorithm/predicates/predicates.go

@@ -812,7 +812,7 @@ func (c *PodAffinityChecker) InterPodAffinityMatches(pod *api.Pod, meta interfac
 		return false, fmt.Errorf("node not found")
 	}
 	if !c.satisfiesExistingPodsAntiAffinity(pod, meta, node) {
-		return false, nil
+		return false, ErrPodAffinityNotMatch
 	}
 
 	// Now check if <pod> requirements will be satisfied on this node.
@@ -824,7 +824,7 @@ func (c *PodAffinityChecker) InterPodAffinityMatches(pod *api.Pod, meta interfac
 		return true, nil
 	}
 	if !c.satisfiesPodsAffinityAntiAffinity(pod, node, affinity) {
-		return false, nil
+		return false, ErrPodAffinityNotMatch
 	}
 
 	if glog.V(10) {

plugin/pkg/scheduler/algorithmprovider/defaults/defaults.go

@@ -93,24 +93,6 @@ func init() {
 	factory.RegisterFitPredicate("HostName", predicates.PodFitsHost)
 	// Fit is determined by node selector query.
 	factory.RegisterFitPredicate("MatchNodeSelector", predicates.PodSelectorMatches)
-	// Fit is determined by inter-pod affinity.
-	factory.RegisterFitPredicateFactory(
-		"MatchInterPodAffinity",
-		func(args factory.PluginFactoryArgs) algorithm.FitPredicate {
-			return predicates.NewPodAffinityPredicate(args.NodeInfo, args.PodLister, args.FailureDomains)
-		},
-	)
-	//pods should be placed in the same topological domain (e.g. same node, same rack, same zone, same power domain, etc.)
-	//as some other pods, or, conversely, should not be placed in the same topological domain as some other pods.
-	factory.RegisterPriorityConfigFactory(
-		"InterPodAffinityPriority",
-		factory.PriorityConfigFactory{
-			Function: func(args factory.PluginFactoryArgs) algorithm.PriorityFunction {
-				return priorities.NewInterPodAffinityPriority(args.NodeInfo, args.NodeLister, args.PodLister, args.HardPodAffinitySymmetricWeight, args.FailureDomains)
-			},
-			Weight: 1,
-		},
-	)
 }
 
 func defaultPredicates() sets.String {
@@ -154,6 +136,14 @@ func defaultPredicates() sets.String {
 
 		// Fit is determined by node disk pressure condition.
 		factory.RegisterFitPredicate("CheckNodeDiskPressure", predicates.CheckNodeDiskPressurePredicate),
+
+		// Fit is determined by inter-pod affinity.
+		factory.RegisterFitPredicateFactory(
+			"MatchInterPodAffinity",
+			func(args factory.PluginFactoryArgs) algorithm.FitPredicate {
+				return predicates.NewPodAffinityPredicate(args.NodeInfo, args.PodLister, args.FailureDomains)
+			},
+		),
 	)
 }
 
@@ -186,5 +176,16 @@ func defaultPriorities() sets.String {
 		),
 		factory.RegisterPriorityFunction("NodeAffinityPriority", priorities.CalculateNodeAffinityPriority, 1),
 		factory.RegisterPriorityFunction("TaintTolerationPriority", priorities.ComputeTaintTolerationPriority, 1),
+		// pods should be placed in the same topological domain (e.g. same node, same rack, same zone, same power domain, etc.)
+		// as some other pods, or, conversely, should not be placed in the same topological domain as some other pods.
+		factory.RegisterPriorityConfigFactory(
+			"InterPodAffinityPriority",
+			factory.PriorityConfigFactory{
+				Function: func(args factory.PluginFactoryArgs) algorithm.PriorityFunction {
+					return priorities.NewInterPodAffinityPriority(args.NodeInfo, args.NodeLister, args.PodLister, args.HardPodAffinitySymmetricWeight, args.FailureDomains)
+				},
+				Weight: 1,
+			},
+		),
 	)
 }

test/e2e/scheduler_predicates.go

@@ -976,7 +976,7 @@ var _ = framework.KubeDescribe("SchedulerPredicates [Serial]", func() {
 		framework.Logf("Sleeping 10 seconds and crossing our fingers that scheduler will run in that time.")
 		time.Sleep(10 * time.Second)
 
-		verifyResult(c, labelPodName, 1, 1, ns)
+		verifyResult(c, labelPodName, 1, 0, ns)
 	})
 
 	// test the pod affinity successful matching scenario with multiple Label Operators.