-
Notifications
You must be signed in to change notification settings - Fork 39.2k
/
range_allocator.go
401 lines (358 loc) · 14.5 KB
/
range_allocator.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
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
/*
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 ipam
import (
"fmt"
"net"
"sync"
"k8s.io/api/core/v1"
"k8s.io/klog/v2"
apierrors "k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/types"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/apimachinery/pkg/util/sets"
informers "k8s.io/client-go/informers/core/v1"
clientset "k8s.io/client-go/kubernetes"
"k8s.io/client-go/kubernetes/scheme"
v1core "k8s.io/client-go/kubernetes/typed/core/v1"
corelisters "k8s.io/client-go/listers/core/v1"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/tools/record"
"k8s.io/kubernetes/pkg/controller/nodeipam/ipam/cidrset"
nodeutil "k8s.io/kubernetes/pkg/controller/util/node"
utilnode "k8s.io/kubernetes/pkg/util/node"
)
// cidrs are reserved, then node resource is patched with them
// this type holds the reservation info for a node
type nodeReservedCIDRs struct {
allocatedCIDRs []*net.IPNet
nodeName string
}
type rangeAllocator struct {
client clientset.Interface
// cluster cidrs as passed in during controller creation
clusterCIDRs []*net.IPNet
// for each entry in clusterCIDRs we maintain a list of what is used and what is not
cidrSets []*cidrset.CidrSet
// nodeLister is able to list/get nodes and is populated by the shared informer passed to controller
nodeLister corelisters.NodeLister
// nodesSynced returns true if the node shared informer has been synced at least once.
nodesSynced cache.InformerSynced
// Channel that is used to pass updating Nodes and their reserved CIDRs to the background
// This increases a throughput of CIDR assignment by not blocking on long operations.
nodeCIDRUpdateChannel chan nodeReservedCIDRs
recorder record.EventRecorder
// Keep a set of nodes that are currently being processed to avoid races in CIDR allocation
lock sync.Mutex
nodesInProcessing sets.String
}
// NewCIDRRangeAllocator returns a CIDRAllocator to allocate CIDRs for node (one from each of clusterCIDRs)
// Caller must ensure subNetMaskSize is not less than cluster CIDR mask size.
// Caller must always pass in a list of existing nodes so the new allocator.
// Caller must ensure that ClusterCIDRs are semantically correct e.g (1 for non DualStack, 2 for DualStack etc..)
// can initialize its CIDR map. NodeList is only nil in testing.
func NewCIDRRangeAllocator(client clientset.Interface, nodeInformer informers.NodeInformer, allocatorParams CIDRAllocatorParams, nodeList *v1.NodeList) (CIDRAllocator, error) {
if client == nil {
klog.Fatalf("kubeClient is nil when starting NodeController")
}
eventBroadcaster := record.NewBroadcaster()
recorder := eventBroadcaster.NewRecorder(scheme.Scheme, v1.EventSource{Component: "cidrAllocator"})
eventBroadcaster.StartStructuredLogging(0)
klog.V(0).Infof("Sending events to api server.")
eventBroadcaster.StartRecordingToSink(&v1core.EventSinkImpl{Interface: client.CoreV1().Events("")})
// create a cidrSet for each cidr we operate on
// cidrSet are mapped to clusterCIDR by index
cidrSets := make([]*cidrset.CidrSet, len(allocatorParams.ClusterCIDRs))
for idx, cidr := range allocatorParams.ClusterCIDRs {
cidrSet, err := cidrset.NewCIDRSet(cidr, allocatorParams.NodeCIDRMaskSizes[idx])
if err != nil {
return nil, err
}
cidrSets[idx] = cidrSet
}
ra := &rangeAllocator{
client: client,
clusterCIDRs: allocatorParams.ClusterCIDRs,
cidrSets: cidrSets,
nodeLister: nodeInformer.Lister(),
nodesSynced: nodeInformer.Informer().HasSynced,
nodeCIDRUpdateChannel: make(chan nodeReservedCIDRs, cidrUpdateQueueSize),
recorder: recorder,
nodesInProcessing: sets.NewString(),
}
if allocatorParams.ServiceCIDR != nil {
ra.filterOutServiceRange(allocatorParams.ServiceCIDR)
} else {
klog.V(0).Info("No Service CIDR provided. Skipping filtering out service addresses.")
}
if allocatorParams.SecondaryServiceCIDR != nil {
ra.filterOutServiceRange(allocatorParams.SecondaryServiceCIDR)
} else {
klog.V(0).Info("No Secondary Service CIDR provided. Skipping filtering out secondary service addresses.")
}
if nodeList != nil {
for _, node := range nodeList.Items {
if len(node.Spec.PodCIDRs) == 0 {
klog.V(4).Infof("Node %v has no CIDR, ignoring", node.Name)
continue
}
klog.V(4).Infof("Node %v has CIDR %s, occupying it in CIDR map", node.Name, node.Spec.PodCIDR)
if err := ra.occupyCIDRs(&node); err != nil {
// This will happen if:
// 1. We find garbage in the podCIDRs field. Retrying is useless.
// 2. CIDR out of range: This means a node CIDR has changed.
// This error will keep crashing controller-manager.
return nil, err
}
}
}
nodeInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
AddFunc: nodeutil.CreateAddNodeHandler(ra.AllocateOrOccupyCIDR),
UpdateFunc: nodeutil.CreateUpdateNodeHandler(func(_, newNode *v1.Node) error {
// If the PodCIDRs list is not empty we either:
// - already processed a Node that already had CIDRs after NC restarted
// (cidr is marked as used),
// - already processed a Node successfully and allocated CIDRs for it
// (cidr is marked as used),
// - already processed a Node but we did saw a "timeout" response and
// request eventually got through in this case we haven't released
// the allocated CIDRs (cidr is still marked as used).
// There's a possible error here:
// - NC sees a new Node and assigns CIDRs X,Y.. to it,
// - Update Node call fails with a timeout,
// - Node is updated by some other component, NC sees an update and
// assigns CIDRs A,B.. to the Node,
// - Both CIDR X,Y.. and CIDR A,B.. are marked as used in the local cache,
// even though Node sees only CIDR A,B..
// The problem here is that in in-memory cache we see CIDR X,Y.. as marked,
// which prevents it from being assigned to any new node. The cluster
// state is correct.
// Restart of NC fixes the issue.
if len(newNode.Spec.PodCIDRs) == 0 {
return ra.AllocateOrOccupyCIDR(newNode)
}
return nil
}),
DeleteFunc: nodeutil.CreateDeleteNodeHandler(ra.ReleaseCIDR),
})
return ra, nil
}
func (r *rangeAllocator) Run(stopCh <-chan struct{}) {
defer utilruntime.HandleCrash()
klog.Infof("Starting range CIDR allocator")
defer klog.Infof("Shutting down range CIDR allocator")
if !cache.WaitForNamedCacheSync("cidrallocator", stopCh, r.nodesSynced) {
return
}
for i := 0; i < cidrUpdateWorkers; i++ {
go r.worker(stopCh)
}
<-stopCh
}
func (r *rangeAllocator) worker(stopChan <-chan struct{}) {
for {
select {
case workItem, ok := <-r.nodeCIDRUpdateChannel:
if !ok {
klog.Warning("Channel nodeCIDRUpdateChannel was unexpectedly closed")
return
}
if err := r.updateCIDRsAllocation(workItem); err != nil {
// Requeue the failed node for update again.
r.nodeCIDRUpdateChannel <- workItem
}
case <-stopChan:
return
}
}
}
func (r *rangeAllocator) insertNodeToProcessing(nodeName string) bool {
r.lock.Lock()
defer r.lock.Unlock()
if r.nodesInProcessing.Has(nodeName) {
return false
}
r.nodesInProcessing.Insert(nodeName)
return true
}
func (r *rangeAllocator) removeNodeFromProcessing(nodeName string) {
r.lock.Lock()
defer r.lock.Unlock()
r.nodesInProcessing.Delete(nodeName)
}
// marks node.PodCIDRs[...] as used in allocator's tracked cidrSet
func (r *rangeAllocator) occupyCIDRs(node *v1.Node) error {
defer r.removeNodeFromProcessing(node.Name)
if len(node.Spec.PodCIDRs) == 0 {
return nil
}
for idx, cidr := range node.Spec.PodCIDRs {
_, podCIDR, err := net.ParseCIDR(cidr)
if err != nil {
return fmt.Errorf("failed to parse node %s, CIDR %s", node.Name, node.Spec.PodCIDR)
}
// If node has a pre allocate cidr that does not exist in our cidrs.
// This will happen if cluster went from dualstack(multi cidrs) to non-dualstack
// then we have now way of locking it
if idx >= len(r.cidrSets) {
return fmt.Errorf("node:%s has an allocated cidr: %v at index:%v that does not exist in cluster cidrs configuration", node.Name, cidr, idx)
}
if err := r.cidrSets[idx].Occupy(podCIDR); err != nil {
return fmt.Errorf("failed to mark cidr[%v] at idx [%v] as occupied for node: %v: %v", podCIDR, idx, node.Name, err)
}
}
return nil
}
// WARNING: If you're adding any return calls or defer any more work from this
// function you have to make sure to update nodesInProcessing properly with the
// disposition of the node when the work is done.
func (r *rangeAllocator) AllocateOrOccupyCIDR(node *v1.Node) error {
if node == nil {
return nil
}
if !r.insertNodeToProcessing(node.Name) {
klog.V(2).Infof("Node %v is already in a process of CIDR assignment.", node.Name)
return nil
}
if len(node.Spec.PodCIDRs) > 0 {
return r.occupyCIDRs(node)
}
// allocate and queue the assignment
allocated := nodeReservedCIDRs{
nodeName: node.Name,
allocatedCIDRs: make([]*net.IPNet, len(r.cidrSets)),
}
for idx := range r.cidrSets {
podCIDR, err := r.cidrSets[idx].AllocateNext()
if err != nil {
r.removeNodeFromProcessing(node.Name)
nodeutil.RecordNodeStatusChange(r.recorder, node, "CIDRNotAvailable")
return fmt.Errorf("failed to allocate cidr from cluster cidr at idx:%v: %v", idx, err)
}
allocated.allocatedCIDRs[idx] = podCIDR
}
//queue the assignment
klog.V(4).Infof("Putting node %s with CIDR %v into the work queue", node.Name, allocated.allocatedCIDRs)
r.nodeCIDRUpdateChannel <- allocated
return nil
}
// ReleaseCIDR marks node.podCIDRs[...] as unused in our tracked cidrSets
func (r *rangeAllocator) ReleaseCIDR(node *v1.Node) error {
if node == nil || len(node.Spec.PodCIDRs) == 0 {
return nil
}
for idx, cidr := range node.Spec.PodCIDRs {
_, podCIDR, err := net.ParseCIDR(cidr)
if err != nil {
return fmt.Errorf("failed to parse CIDR %s on Node %v: %v", cidr, node.Name, err)
}
// If node has a pre allocate cidr that does not exist in our cidrs.
// This will happen if cluster went from dualstack(multi cidrs) to non-dualstack
// then we have now way of locking it
if idx >= len(r.cidrSets) {
return fmt.Errorf("node:%s has an allocated cidr: %v at index:%v that does not exist in cluster cidrs configuration", node.Name, cidr, idx)
}
klog.V(4).Infof("release CIDR %s for node:%v", cidr, node.Name)
if err = r.cidrSets[idx].Release(podCIDR); err != nil {
return fmt.Errorf("error when releasing CIDR %v: %v", cidr, err)
}
}
return nil
}
// Marks all CIDRs with subNetMaskSize that belongs to serviceCIDR as used across all cidrs
// so that they won't be assignable.
func (r *rangeAllocator) filterOutServiceRange(serviceCIDR *net.IPNet) {
// Checks if service CIDR has a nonempty intersection with cluster
// CIDR. It is the case if either clusterCIDR contains serviceCIDR with
// clusterCIDR's Mask applied (this means that clusterCIDR contains
// serviceCIDR) or vice versa (which means that serviceCIDR contains
// clusterCIDR).
for idx, cidr := range r.clusterCIDRs {
// if they don't overlap then ignore the filtering
if !cidr.Contains(serviceCIDR.IP.Mask(cidr.Mask)) && !serviceCIDR.Contains(cidr.IP.Mask(serviceCIDR.Mask)) {
continue
}
// at this point, len(cidrSet) == len(clusterCidr)
if err := r.cidrSets[idx].Occupy(serviceCIDR); err != nil {
klog.Errorf("Error filtering out service cidr out cluster cidr:%v (index:%v) %v: %v", cidr, idx, serviceCIDR, err)
}
}
}
// updateCIDRsAllocation assigns CIDR to Node and sends an update to the API server.
func (r *rangeAllocator) updateCIDRsAllocation(data nodeReservedCIDRs) error {
var err error
var node *v1.Node
defer r.removeNodeFromProcessing(data.nodeName)
cidrsString := cidrsAsString(data.allocatedCIDRs)
node, err = r.nodeLister.Get(data.nodeName)
if err != nil {
klog.Errorf("Failed while getting node %v for updating Node.Spec.PodCIDRs: %v", data.nodeName, err)
return err
}
// if cidr list matches the proposed.
// then we possibly updated this node
// and just failed to ack the success.
if len(node.Spec.PodCIDRs) == len(data.allocatedCIDRs) {
match := true
for idx, cidr := range cidrsString {
if node.Spec.PodCIDRs[idx] != cidr {
match = false
break
}
}
if match {
klog.V(4).Infof("Node %v already has allocated CIDR %v. It matches the proposed one.", node.Name, data.allocatedCIDRs)
return nil
}
}
// node has cidrs, release the reserved
if len(node.Spec.PodCIDRs) != 0 {
klog.Errorf("Node %v already has a CIDR allocated %v. Releasing the new one.", node.Name, node.Spec.PodCIDRs)
for idx, cidr := range data.allocatedCIDRs {
if releaseErr := r.cidrSets[idx].Release(cidr); releaseErr != nil {
klog.Errorf("Error when releasing CIDR idx:%v value: %v err:%v", idx, cidr, releaseErr)
}
}
return nil
}
// If we reached here, it means that the node has no CIDR currently assigned. So we set it.
for i := 0; i < cidrUpdateRetries; i++ {
if err = utilnode.PatchNodeCIDRs(r.client, types.NodeName(node.Name), cidrsString); err == nil {
klog.Infof("Set node %v PodCIDR to %v", node.Name, cidrsString)
return nil
}
}
// failed release back to the pool
klog.Errorf("Failed to update node %v PodCIDR to %v after multiple attempts: %v", node.Name, cidrsString, err)
nodeutil.RecordNodeStatusChange(r.recorder, node, "CIDRAssignmentFailed")
// We accept the fact that we may leak CIDRs here. This is safer than releasing
// them in case when we don't know if request went through.
// NodeController restart will return all falsely allocated CIDRs to the pool.
if !apierrors.IsServerTimeout(err) {
klog.Errorf("CIDR assignment for node %v failed: %v. Releasing allocated CIDR", node.Name, err)
for idx, cidr := range data.allocatedCIDRs {
if releaseErr := r.cidrSets[idx].Release(cidr); releaseErr != nil {
klog.Errorf("Error releasing allocated CIDR for node %v: %v", node.Name, releaseErr)
}
}
}
return err
}
// converts a slice of cidrs into <c-1>,<c-2>,<c-n>
func cidrsAsString(inCIDRs []*net.IPNet) []string {
outCIDRs := make([]string, len(inCIDRs))
for idx, inCIDR := range inCIDRs {
outCIDRs[idx] = inCIDR.String()
}
return outCIDRs
}