forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 0
/
dns_autoscaling.go
365 lines (315 loc) · 13 KB
/
dns_autoscaling.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
/*
Copyright 2016 The Kubernetes Authors.
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 autoscaling
import (
"fmt"
"math"
"strings"
"time"
"k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/api/resource"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/util/wait"
clientset "k8s.io/client-go/kubernetes"
"k8s.io/kubernetes/test/e2e/framework"
. "github.com/onsi/ginkgo"
. "github.com/onsi/gomega"
)
const (
DNSdefaultTimeout = 5 * time.Minute
ClusterAddonLabelKey = "k8s-app"
DNSLabelName = "kube-dns"
DNSAutoscalerLabelName = "kube-dns-autoscaler"
)
var _ = SIGDescribe("DNS horizontal autoscaling", func() {
f := framework.NewDefaultFramework("dns-autoscaling")
var c clientset.Interface
var previousParams map[string]string
var originDNSReplicasCount int
var DNSParams_1 DNSParamsLinear
var DNSParams_2 DNSParamsLinear
var DNSParams_3 DNSParamsLinear
BeforeEach(func() {
framework.SkipUnlessProviderIs("gce", "gke")
c = f.ClientSet
nodeCount := len(framework.GetReadySchedulableNodesOrDie(c).Items)
Expect(nodeCount).NotTo(BeZero())
By("Collecting original replicas count and DNS scaling params")
var err error
originDNSReplicasCount, err = getDNSReplicas(c)
Expect(err).NotTo(HaveOccurred())
pcm, err := fetchDNSScalingConfigMap(c)
Expect(err).NotTo(HaveOccurred())
previousParams = pcm.Data
if nodeCount <= 500 {
DNSParams_1 = DNSParamsLinear{
nodesPerReplica: 1,
}
DNSParams_2 = DNSParamsLinear{
nodesPerReplica: 2,
}
DNSParams_3 = DNSParamsLinear{
nodesPerReplica: 3,
coresPerReplica: 3,
}
} else {
// In large clusters, avoid creating/deleting too many DNS pods,
// it is supposed to be correctness test, not performance one.
// The default setup is: 256 cores/replica, 16 nodes/replica.
// With nodeCount > 500, nodes/13, nodes/14, nodes/15 and nodes/16
// are different numbers.
DNSParams_1 = DNSParamsLinear{
nodesPerReplica: 13,
}
DNSParams_2 = DNSParamsLinear{
nodesPerReplica: 14,
}
DNSParams_3 = DNSParamsLinear{
nodesPerReplica: 15,
coresPerReplica: 15,
}
}
})
// This test is separated because it is slow and need to run serially.
// Will take around 5 minutes to run on a 4 nodes cluster.
It("[Serial] [Slow] kube-dns-autoscaler should scale kube-dns pods when cluster size changed", func() {
By("Replace the dns autoscaling parameters with testing parameters")
err := updateDNSScalingConfigMap(c, packDNSScalingConfigMap(packLinearParams(&DNSParams_1)))
Expect(err).NotTo(HaveOccurred())
defer func() {
By("Restoring intial dns autoscaling parameters")
Expect(updateDNSScalingConfigMap(c, packDNSScalingConfigMap(previousParams))).NotTo(HaveOccurred())
By("Wait for number of running and ready kube-dns pods recover")
label := labels.SelectorFromSet(labels.Set(map[string]string{ClusterAddonLabelKey: DNSLabelName}))
_, err := framework.WaitForPodsWithLabelRunningReady(c, metav1.NamespaceSystem, label, originDNSReplicasCount, DNSdefaultTimeout)
Expect(err).NotTo(HaveOccurred())
}()
By("Wait for kube-dns scaled to expected number")
getExpectReplicasLinear := getExpectReplicasFuncLinear(c, &DNSParams_1)
Expect(waitForDNSReplicasSatisfied(c, getExpectReplicasLinear, DNSdefaultTimeout)).NotTo(HaveOccurred())
originalSizes := make(map[string]int)
sum := 0
for _, mig := range strings.Split(framework.TestContext.CloudConfig.NodeInstanceGroup, ",") {
size, err := framework.GroupSize(mig)
Expect(err).NotTo(HaveOccurred())
By(fmt.Sprintf("Initial size of %s: %d", mig, size))
originalSizes[mig] = size
sum += size
}
By("Manually increase cluster size")
increasedSize := 0
increasedSizes := make(map[string]int)
for key, val := range originalSizes {
increasedSizes[key] = val + 1
increasedSize += increasedSizes[key]
}
setMigSizes(increasedSizes)
Expect(WaitForClusterSizeFunc(c,
func(size int) bool { return size == increasedSize }, scaleUpTimeout)).NotTo(HaveOccurred())
By("Wait for kube-dns scaled to expected number")
getExpectReplicasLinear = getExpectReplicasFuncLinear(c, &DNSParams_1)
Expect(waitForDNSReplicasSatisfied(c, getExpectReplicasLinear, DNSdefaultTimeout)).NotTo(HaveOccurred())
By("Replace the dns autoscaling parameters with another testing parameters")
err = updateDNSScalingConfigMap(c, packDNSScalingConfigMap(packLinearParams(&DNSParams_3)))
Expect(err).NotTo(HaveOccurred())
By("Wait for kube-dns scaled to expected number")
getExpectReplicasLinear = getExpectReplicasFuncLinear(c, &DNSParams_3)
Expect(waitForDNSReplicasSatisfied(c, getExpectReplicasLinear, DNSdefaultTimeout)).NotTo(HaveOccurred())
By("Restoring cluster size")
setMigSizes(originalSizes)
Expect(framework.WaitForClusterSize(c, sum, scaleDownTimeout)).NotTo(HaveOccurred())
By("Wait for kube-dns scaled to expected number")
Expect(waitForDNSReplicasSatisfied(c, getExpectReplicasLinear, DNSdefaultTimeout)).NotTo(HaveOccurred())
})
It("kube-dns-autoscaler should scale kube-dns pods in both nonfaulty and faulty scenarios", func() {
By("Replace the dns autoscaling parameters with testing parameters")
err := updateDNSScalingConfigMap(c, packDNSScalingConfigMap(packLinearParams(&DNSParams_1)))
Expect(err).NotTo(HaveOccurred())
defer func() {
By("Restoring intial dns autoscaling parameters")
Expect(updateDNSScalingConfigMap(c, packDNSScalingConfigMap(previousParams))).NotTo(HaveOccurred())
}()
By("Wait for kube-dns scaled to expected number")
getExpectReplicasLinear := getExpectReplicasFuncLinear(c, &DNSParams_1)
Expect(waitForDNSReplicasSatisfied(c, getExpectReplicasLinear, DNSdefaultTimeout)).NotTo(HaveOccurred())
By("--- Scenario: should scale kube-dns based on changed parameters ---")
By("Replace the dns autoscaling parameters with another testing parameters")
err = updateDNSScalingConfigMap(c, packDNSScalingConfigMap(packLinearParams(&DNSParams_3)))
Expect(err).NotTo(HaveOccurred())
By("Wait for kube-dns scaled to expected number")
getExpectReplicasLinear = getExpectReplicasFuncLinear(c, &DNSParams_3)
Expect(waitForDNSReplicasSatisfied(c, getExpectReplicasLinear, DNSdefaultTimeout)).NotTo(HaveOccurred())
By("--- Scenario: should re-create scaling parameters with default value when parameters got deleted ---")
By("Delete the ConfigMap for autoscaler")
err = deleteDNSScalingConfigMap(c)
Expect(err).NotTo(HaveOccurred())
By("Wait for the ConfigMap got re-created")
_, err = waitForDNSConfigMapCreated(c, DNSdefaultTimeout)
Expect(err).NotTo(HaveOccurred())
By("Replace the dns autoscaling parameters with another testing parameters")
err = updateDNSScalingConfigMap(c, packDNSScalingConfigMap(packLinearParams(&DNSParams_2)))
Expect(err).NotTo(HaveOccurred())
By("Wait for kube-dns scaled to expected number")
getExpectReplicasLinear = getExpectReplicasFuncLinear(c, &DNSParams_2)
Expect(waitForDNSReplicasSatisfied(c, getExpectReplicasLinear, DNSdefaultTimeout)).NotTo(HaveOccurred())
By("--- Scenario: should recover after autoscaler pod got deleted ---")
By("Delete the autoscaler pod for kube-dns")
Expect(deleteDNSAutoscalerPod(c)).NotTo(HaveOccurred())
By("Replace the dns autoscaling parameters with another testing parameters")
err = updateDNSScalingConfigMap(c, packDNSScalingConfigMap(packLinearParams(&DNSParams_1)))
Expect(err).NotTo(HaveOccurred())
By("Wait for kube-dns scaled to expected number")
getExpectReplicasLinear = getExpectReplicasFuncLinear(c, &DNSParams_1)
Expect(waitForDNSReplicasSatisfied(c, getExpectReplicasLinear, DNSdefaultTimeout)).NotTo(HaveOccurred())
})
})
type DNSParamsLinear struct {
nodesPerReplica float64
coresPerReplica float64
min int
max int
}
type getExpectReplicasFunc func(c clientset.Interface) int
func getExpectReplicasFuncLinear(c clientset.Interface, params *DNSParamsLinear) getExpectReplicasFunc {
return func(c clientset.Interface) int {
var replicasFromNodes float64
var replicasFromCores float64
nodes := framework.GetReadySchedulableNodesOrDie(c).Items
if params.nodesPerReplica > 0 {
replicasFromNodes = math.Ceil(float64(len(nodes)) / params.nodesPerReplica)
}
if params.coresPerReplica > 0 {
replicasFromCores = math.Ceil(float64(getScheduableCores(nodes)) / params.coresPerReplica)
}
return int(math.Max(1.0, math.Max(replicasFromNodes, replicasFromCores)))
}
}
func getScheduableCores(nodes []v1.Node) int64 {
var sc resource.Quantity
for _, node := range nodes {
if !node.Spec.Unschedulable {
sc.Add(node.Status.Capacity[v1.ResourceCPU])
}
}
scInt64, scOk := sc.AsInt64()
if !scOk {
framework.Logf("Unable to compute integer values of schedulable cores in the cluster")
return 0
}
return scInt64
}
func fetchDNSScalingConfigMap(c clientset.Interface) (*v1.ConfigMap, error) {
cm, err := c.Core().ConfigMaps(metav1.NamespaceSystem).Get(DNSAutoscalerLabelName, metav1.GetOptions{})
if err != nil {
return nil, err
}
return cm, nil
}
func deleteDNSScalingConfigMap(c clientset.Interface) error {
if err := c.Core().ConfigMaps(metav1.NamespaceSystem).Delete(DNSAutoscalerLabelName, nil); err != nil {
return err
}
framework.Logf("DNS autoscaling ConfigMap deleted.")
return nil
}
func packLinearParams(params *DNSParamsLinear) map[string]string {
paramsMap := make(map[string]string)
paramsMap["linear"] = fmt.Sprintf("{\"nodesPerReplica\": %v,\"coresPerReplica\": %v,\"min\": %v,\"max\": %v}",
params.nodesPerReplica,
params.coresPerReplica,
params.min,
params.max)
return paramsMap
}
func packDNSScalingConfigMap(params map[string]string) *v1.ConfigMap {
configMap := v1.ConfigMap{}
configMap.ObjectMeta.Name = DNSAutoscalerLabelName
configMap.ObjectMeta.Namespace = metav1.NamespaceSystem
configMap.Data = params
return &configMap
}
func updateDNSScalingConfigMap(c clientset.Interface, configMap *v1.ConfigMap) error {
_, err := c.Core().ConfigMaps(metav1.NamespaceSystem).Update(configMap)
if err != nil {
return err
}
framework.Logf("DNS autoscaling ConfigMap updated.")
return nil
}
func getDNSReplicas(c clientset.Interface) (int, error) {
label := labels.SelectorFromSet(labels.Set(map[string]string{ClusterAddonLabelKey: DNSLabelName}))
listOpts := metav1.ListOptions{LabelSelector: label.String()}
deployments, err := c.Extensions().Deployments(metav1.NamespaceSystem).List(listOpts)
if err != nil {
return 0, err
}
if len(deployments.Items) != 1 {
return 0, fmt.Errorf("expected 1 DNS deployment, got %v", len(deployments.Items))
}
deployment := deployments.Items[0]
return int(*(deployment.Spec.Replicas)), nil
}
func deleteDNSAutoscalerPod(c clientset.Interface) error {
label := labels.SelectorFromSet(labels.Set(map[string]string{ClusterAddonLabelKey: DNSAutoscalerLabelName}))
listOpts := metav1.ListOptions{LabelSelector: label.String()}
pods, err := c.Core().Pods(metav1.NamespaceSystem).List(listOpts)
if err != nil {
return err
}
if len(pods.Items) != 1 {
return fmt.Errorf("expected 1 autoscaler pod, got %v", len(pods.Items))
}
podName := pods.Items[0].Name
if err := c.Core().Pods(metav1.NamespaceSystem).Delete(podName, nil); err != nil {
return err
}
framework.Logf("DNS autoscaling pod %v deleted.", podName)
return nil
}
func waitForDNSReplicasSatisfied(c clientset.Interface, getExpected getExpectReplicasFunc, timeout time.Duration) (err error) {
var current int
var expected int
framework.Logf("Waiting up to %v for kube-dns to reach expected replicas", timeout)
condition := func() (bool, error) {
current, err = getDNSReplicas(c)
if err != nil {
return false, err
}
expected = getExpected(c)
if current != expected {
framework.Logf("Replicas not as expected: got %v, expected %v", current, expected)
return false, nil
}
return true, nil
}
if err = wait.Poll(2*time.Second, timeout, condition); err != nil {
return fmt.Errorf("err waiting for DNS replicas to satisfy %v, got %v: %v", expected, current, err)
}
framework.Logf("kube-dns reaches expected replicas: %v", expected)
return nil
}
func waitForDNSConfigMapCreated(c clientset.Interface, timeout time.Duration) (configMap *v1.ConfigMap, err error) {
framework.Logf("Waiting up to %v for DNS autoscaling ConfigMap got re-created", timeout)
condition := func() (bool, error) {
configMap, err = fetchDNSScalingConfigMap(c)
if err != nil {
return false, nil
}
return true, nil
}
if err = wait.Poll(time.Second, timeout, condition); err != nil {
return nil, fmt.Errorf("err waiting for DNS autoscaling ConfigMap got re-created: %v", err)
}
return configMap, nil
}