Revert "Remove FailedResourceType and return custom error"

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

-/*
-Copyright 2016 The Kubernetes Authors All rights reserved.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package predicates
-
-import "fmt"
-
-var (
-	ErrExceededMaxPodNumber   = newInsufficientResourceError("PodCount")
-	ErrInsufficientFreeCPU    = newInsufficientResourceError("CPU")
-	ErrInsufficientFreeMemory = newInsufficientResourceError("Memory")
-)
-
-// InsufficientResourceError is an error type that indicates what kind of resource limit is
-// hit and caused the unfitting failure.
-type InsufficientResourceError struct {
-	// ResourceName tells the name of the resource that is insufficient
-	ResourceName string
-}
-
-func newInsufficientResourceError(resourceName string) *InsufficientResourceError {
-	return &InsufficientResourceError{resourceName}
-}
-
-func (e *InsufficientResourceError) Error() string {
-	return fmt.Sprintf("Node didn't have enough resource: %s", e.ResourceName)
-}

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

@@ -256,6 +256,8 @@ type resourceRequest struct {
 	memory   int64
 }
 
+var FailedResourceType string
+
 func getResourceRequest(pod *api.Pod) resourceRequest {
 	result := resourceRequest{}
 	for _, container := range pod.Spec.Containers {
@@ -306,7 +308,8 @@ func (r *ResourceFit) PodFitsResources(pod *api.Pod, existingPods []*api.Pod, no
 
 	if int64(len(existingPods))+1 > info.Status.Capacity.Pods().Value() {
 		glog.V(10).Infof("Cannot schedule Pod %+v, because Node %+v is full, running %v out of %v Pods.", podName(pod), node, len(existingPods), info.Status.Capacity.Pods().Value())
-		return false, ErrExceededMaxPodNumber
+		FailedResourceType = "PodExceedsMaxPodNumber"
+		return false, nil
 	}
 
 	podRequest := getResourceRequest(pod)
@@ -318,11 +321,13 @@ func (r *ResourceFit) PodFitsResources(pod *api.Pod, existingPods []*api.Pod, no
 	_, exceedingCPU, exceedingMemory := CheckPodsExceedingFreeResources(pods, info.Status.Capacity)
 	if len(exceedingCPU) > 0 {
 		glog.V(10).Infof("Cannot schedule Pod %+v, because Node %v does not have sufficient CPU", podName(pod), node)
-		return false, ErrInsufficientFreeCPU
+		FailedResourceType = "PodExceedsFreeCPU"
+		return false, nil
 	}
 	if len(exceedingMemory) > 0 {
 		glog.V(10).Infof("Cannot schedule Pod %+v, because Node %v does not have sufficient Memory", podName(pod), node)
-		return false, ErrInsufficientFreeMemory
+		FailedResourceType = "PodExceedsFreeMemory"
+		return false, nil
 	}
 	glog.V(10).Infof("Schedule Pod %+v on Node %+v is allowed, Node is running only %v out of %v Pods.", podName(pod), node, len(pods)-1, info.Status.Capacity.Pods().Value())
 	return true, nil

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

@@ -80,7 +80,6 @@ func TestPodFitsResources(t *testing.T) {
 		existingPods []*api.Pod
 		fits         bool
 		test         string
-		wErr         error
 	}{
 		{
 			pod: &api.Pod{},
@@ -89,7 +88,6 @@ func TestPodFitsResources(t *testing.T) {
 			},
 			fits: true,
 			test: "no resources requested always fits",
-			wErr: nil,
 		},
 		{
 			pod: newResourcePod(resourceRequest{milliCPU: 1, memory: 1}),
@@ -98,7 +96,6 @@ func TestPodFitsResources(t *testing.T) {
 			},
 			fits: false,
 			test: "too many resources fails",
-			wErr: ErrInsufficientFreeCPU,
 		},
 		{
 			pod: newResourcePod(resourceRequest{milliCPU: 1, memory: 1}),
@@ -107,7 +104,6 @@ func TestPodFitsResources(t *testing.T) {
 			},
 			fits: true,
 			test: "both resources fit",
-			wErr: nil,
 		},
 		{
 			pod: newResourcePod(resourceRequest{milliCPU: 1, memory: 2}),
@@ -116,7 +112,6 @@ func TestPodFitsResources(t *testing.T) {
 			},
 			fits: false,
 			test: "one resources fits",
-			wErr: ErrInsufficientFreeMemory,
 		},
 		{
 			pod: newResourcePod(resourceRequest{milliCPU: 5, memory: 1}),
@@ -125,7 +120,6 @@ func TestPodFitsResources(t *testing.T) {
 			},
 			fits: true,
 			test: "equal edge case",
-			wErr: nil,
 		},
 	}
 
@@ -134,8 +128,8 @@ func TestPodFitsResources(t *testing.T) {
 
 		fit := ResourceFit{FakeNodeInfo(node)}
 		fits, err := fit.PodFitsResources(test.pod, test.existingPods, "machine")
-		if !reflect.DeepEqual(err, test.wErr) {
-			t.Errorf("%s: unexpected error: %v, want: %v", test.test, err, test.wErr)
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
 		}
 		if fits != test.fits {
 			t.Errorf("%s: expected: %v got %v", test.test, test.fits, fits)
@@ -147,7 +141,6 @@ func TestPodFitsResources(t *testing.T) {
 		existingPods []*api.Pod
 		fits         bool
 		test         string
-		wErr         error
 	}{
 		{
 			pod: &api.Pod{},
@@ -156,7 +149,6 @@ func TestPodFitsResources(t *testing.T) {
 			},
 			fits: false,
 			test: "even without specified resources predicate fails when there's no available ips",
-			wErr: ErrExceededMaxPodNumber,
 		},
 		{
 			pod: newResourcePod(resourceRequest{milliCPU: 1, memory: 1}),
@@ -165,7 +157,6 @@ func TestPodFitsResources(t *testing.T) {
 			},
 			fits: false,
 			test: "even if both resources fit predicate fails when there's no available ips",
-			wErr: ErrExceededMaxPodNumber,
 		},
 		{
 			pod: newResourcePod(resourceRequest{milliCPU: 5, memory: 1}),
@@ -174,7 +165,6 @@ func TestPodFitsResources(t *testing.T) {
 			},
 			fits: false,
 			test: "even for equal edge case predicate fails when there's no available ips",
-			wErr: ErrExceededMaxPodNumber,
 		},
 	}
 	for _, test := range notEnoughPodsTests {
@@ -182,8 +172,8 @@ func TestPodFitsResources(t *testing.T) {
 
 		fit := ResourceFit{FakeNodeInfo(node)}
 		fits, err := fit.PodFitsResources(test.pod, test.existingPods, "machine")
-		if !reflect.DeepEqual(err, test.wErr) {
-			t.Errorf("%s: unexpected error: %v, want: %v", test.test, err, test.wErr)
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
 		}
 		if fits != test.fits {
 			t.Errorf("%s: expected: %v got %v", test.test, test.fits, fits)

plugin/pkg/scheduler/generic_scheduler.go

@@ -127,6 +127,7 @@ func findNodesThatFit(pod *api.Pod, machineToPods map[string][]*api.Pod, predica
 	for _, node := range nodes.Items {
 		fits := true
 		for name, predicate := range predicateFuncs {
+			predicates.FailedResourceType = ""
 			fit, err := predicate(pod, machineToPods[node.Name], node.Name)
 			if err != nil {
 				return api.NodeList{}, FailedPredicateMap{}, err
@@ -136,8 +137,8 @@ func findNodesThatFit(pod *api.Pod, machineToPods map[string][]*api.Pod, predica
 				if _, found := failedPredicateMap[node.Name]; !found {
 					failedPredicateMap[node.Name] = sets.String{}
 				}
-				if re, ok := err.(*predicates.InsufficientResourceError); ok {
-					failedPredicateMap[node.Name].Insert(re.ResourceName)
+				if predicates.FailedResourceType != "" {
+					failedPredicateMap[node.Name].Insert(predicates.FailedResourceType)
 					break
 				}
 				failedPredicateMap[node.Name].Insert(name)