forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 0
/
util.go
236 lines (203 loc) · 7.74 KB
/
util.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
/*
Copyright 2015 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 endpoints
import (
"bytes"
"crypto/md5"
"encoding/hex"
"hash"
"sort"
"k8s.io/kubernetes/pkg/api"
"k8s.io/kubernetes/pkg/types"
hashutil "k8s.io/kubernetes/pkg/util/hash"
)
const (
// Its value is the json representation of map[string(IP)][HostRecord]
// example: '{"10.245.1.6":{"HostName":"my-webserver"}}'
PodHostnamesAnnotation = "endpoints.beta.kubernetes.io/hostnames-map"
)
type HostRecord struct {
HostName string
}
// RepackSubsets takes a slice of EndpointSubset objects, expands it to the full
// representation, and then repacks that into the canonical layout. This
// ensures that code which operates on these objects can rely on the common
// form for things like comparison. The result is a newly allocated slice.
func RepackSubsets(subsets []api.EndpointSubset) []api.EndpointSubset {
// First map each unique port definition to the sets of hosts that
// offer it.
allAddrs := map[addressKey]*api.EndpointAddress{}
portToAddrReadyMap := map[api.EndpointPort]addressSet{}
for i := range subsets {
for _, port := range subsets[i].Ports {
for k := range subsets[i].Addresses {
mapAddressByPort(&subsets[i].Addresses[k], port, true, allAddrs, portToAddrReadyMap)
}
for k := range subsets[i].NotReadyAddresses {
mapAddressByPort(&subsets[i].NotReadyAddresses[k], port, false, allAddrs, portToAddrReadyMap)
}
}
}
// Next, map the sets of hosts to the sets of ports they offer.
// Go does not allow maps or slices as keys to maps, so we have
// to synthesize an artificial key and do a sort of 2-part
// associative entity.
type keyString string
keyToAddrReadyMap := map[keyString]addressSet{}
addrReadyMapKeyToPorts := map[keyString][]api.EndpointPort{}
for port, addrs := range portToAddrReadyMap {
key := keyString(hashAddresses(addrs))
keyToAddrReadyMap[key] = addrs
addrReadyMapKeyToPorts[key] = append(addrReadyMapKeyToPorts[key], port)
}
// Next, build the N-to-M association the API wants.
final := []api.EndpointSubset{}
for key, ports := range addrReadyMapKeyToPorts {
var readyAddrs, notReadyAddrs []api.EndpointAddress
for addr, ready := range keyToAddrReadyMap[key] {
if ready {
readyAddrs = append(readyAddrs, *addr)
} else {
notReadyAddrs = append(notReadyAddrs, *addr)
}
}
final = append(final, api.EndpointSubset{Addresses: readyAddrs, NotReadyAddresses: notReadyAddrs, Ports: ports})
}
// Finally, sort it.
return SortSubsets(final)
}
// The sets of hosts must be de-duped, using IP+UID as the key.
type addressKey struct {
ip string
uid types.UID
}
// mapAddressByPort adds an address into a map by its ports, registering the address with a unique pointer, and preserving
// any existing ready state.
func mapAddressByPort(addr *api.EndpointAddress, port api.EndpointPort, ready bool, allAddrs map[addressKey]*api.EndpointAddress, portToAddrReadyMap map[api.EndpointPort]addressSet) *api.EndpointAddress {
// use addressKey to distinguish between two endpoints that are identical addresses
// but may have come from different hosts, for attribution. For instance, Mesos
// assigns pods the node IP, but the pods are distinct.
key := addressKey{ip: addr.IP}
if addr.TargetRef != nil {
key.uid = addr.TargetRef.UID
}
// Accumulate the address. The full EndpointAddress structure is preserved for use when
// we rebuild the subsets so that the final TargetRef has all of the necessary data.
existingAddress := allAddrs[key]
if existingAddress == nil {
// Make a copy so we don't write to the
// input args of this function.
existingAddress = &api.EndpointAddress{}
*existingAddress = *addr
allAddrs[key] = existingAddress
}
// Remember that this port maps to this address.
if _, found := portToAddrReadyMap[port]; !found {
portToAddrReadyMap[port] = addressSet{}
}
// if we have not yet recorded this port for this address, or if the previous
// state was ready, write the current ready state. not ready always trumps
// ready.
if wasReady, found := portToAddrReadyMap[port][existingAddress]; !found || wasReady {
portToAddrReadyMap[port][existingAddress] = ready
}
return existingAddress
}
type addressSet map[*api.EndpointAddress]bool
type addrReady struct {
addr *api.EndpointAddress
ready bool
}
func hashAddresses(addrs addressSet) string {
// Flatten the list of addresses into a string so it can be used as a
// map key. Unfortunately, DeepHashObject is implemented in terms of
// spew, and spew does not handle non-primitive map keys well. So
// first we collapse it into a slice, sort the slice, then hash that.
slice := make([]addrReady, 0, len(addrs))
for k, ready := range addrs {
slice = append(slice, addrReady{k, ready})
}
sort.Sort(addrsReady(slice))
hasher := md5.New()
hashutil.DeepHashObject(hasher, slice)
return hex.EncodeToString(hasher.Sum(nil)[0:])
}
func lessAddrReady(a, b addrReady) bool {
// ready is not significant to hashing since we can't have duplicate addresses
return LessEndpointAddress(a.addr, b.addr)
}
type addrsReady []addrReady
func (sl addrsReady) Len() int { return len(sl) }
func (sl addrsReady) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
func (sl addrsReady) Less(i, j int) bool {
return lessAddrReady(sl[i], sl[j])
}
func LessEndpointAddress(a, b *api.EndpointAddress) bool {
ipComparison := bytes.Compare([]byte(a.IP), []byte(b.IP))
if ipComparison != 0 {
return ipComparison < 0
}
if b.TargetRef == nil {
return false
}
if a.TargetRef == nil {
return true
}
return a.TargetRef.UID < b.TargetRef.UID
}
type addrPtrsByIpAndUID []*api.EndpointAddress
func (sl addrPtrsByIpAndUID) Len() int { return len(sl) }
func (sl addrPtrsByIpAndUID) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
func (sl addrPtrsByIpAndUID) Less(i, j int) bool {
return LessEndpointAddress(sl[i], sl[j])
}
// SortSubsets sorts an array of EndpointSubset objects in place. For ease of
// use it returns the input slice.
func SortSubsets(subsets []api.EndpointSubset) []api.EndpointSubset {
for i := range subsets {
ss := &subsets[i]
sort.Sort(addrsByIpAndUID(ss.Addresses))
sort.Sort(addrsByIpAndUID(ss.NotReadyAddresses))
sort.Sort(portsByHash(ss.Ports))
}
sort.Sort(subsetsByHash(subsets))
return subsets
}
func hashObject(hasher hash.Hash, obj interface{}) []byte {
hashutil.DeepHashObject(hasher, obj)
return hasher.Sum(nil)
}
type subsetsByHash []api.EndpointSubset
func (sl subsetsByHash) Len() int { return len(sl) }
func (sl subsetsByHash) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
func (sl subsetsByHash) Less(i, j int) bool {
hasher := md5.New()
h1 := hashObject(hasher, sl[i])
h2 := hashObject(hasher, sl[j])
return bytes.Compare(h1, h2) < 0
}
type addrsByIpAndUID []api.EndpointAddress
func (sl addrsByIpAndUID) Len() int { return len(sl) }
func (sl addrsByIpAndUID) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
func (sl addrsByIpAndUID) Less(i, j int) bool {
return LessEndpointAddress(&sl[i], &sl[j])
}
type portsByHash []api.EndpointPort
func (sl portsByHash) Len() int { return len(sl) }
func (sl portsByHash) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
func (sl portsByHash) Less(i, j int) bool {
hasher := md5.New()
h1 := hashObject(hasher, sl[i])
h2 := hashObject(hasher, sl[j])
return bytes.Compare(h1, h2) < 0
}