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
|
// Package kubernetes provides the kubernetes backend.
package kubernetes
import (
"fmt"
"strings"
"time"
"github.com/miekg/coredns/middleware"
"github.com/miekg/coredns/middleware/kubernetes/msg"
k8sc "github.com/miekg/coredns/middleware/kubernetes/k8sclient"
"github.com/miekg/coredns/middleware/proxy"
// "github.com/miekg/coredns/middleware/singleflight"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
type Kubernetes struct {
Next middleware.Handler
Zones []string
Proxy proxy.Proxy // Proxy for looking up names during the resolution process
Ctx context.Context
// Inflight *singleflight.Group
APIConn *k8sc.K8sConnector
}
func (g Kubernetes) getZoneForName(name string) (string, []string) {
/*
* getZoneForName returns the zone string that matches the name and a
* list of the DNS labels from name that are within the zone.
* For example, if "coredns.local" is a zone configured for the
* Kubernetes middleware, then getZoneForName("a.b.coredns.local")
* will return ("coredns.local", ["a", "b"]).
*/
var zone string
var serviceSegments []string
for _, z := range g.Zones {
if dns.IsSubDomain(z, name) {
zone = z
serviceSegments = dns.SplitDomainName(name)
serviceSegments = serviceSegments[:len(serviceSegments) - dns.CountLabel(zone)]
break
}
}
return zone, serviceSegments
}
// Records looks up services in kubernetes.
// If exact is true, it will lookup just
// this name. This is used when find matches when completing SRV lookups
// for instance.
func (g Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
fmt.Println("enter Records('", name, "', ", exact, ")")
zone, serviceSegments := g.getZoneForName(name)
var serviceName string
var namespace string
// For initial implementation, assume namespace is first serviceSegment
// and service name is remaining segments.
serviceSegLen := len(serviceSegments)
if serviceSegLen >= 2 {
namespace = serviceSegments[serviceSegLen-1]
serviceName = strings.Join(serviceSegments[:serviceSegLen-1], ".")
}
// else we are looking up the zone. So handle the NS, SOA records etc.
fmt.Println("[debug] zone: ", zone)
fmt.Println("[debug] servicename: ", serviceName)
fmt.Println("[debug] namespace: ", namespace)
fmt.Println("[debug] APIconn: ", g.APIConn)
k8sItem := g.APIConn.GetServiceItemInNamespace(namespace, serviceName)
fmt.Println("[debug] k8s item:", k8sItem)
switch {
case exact && k8sItem == nil:
fmt.Println("here2")
return nil, nil
}
if k8sItem == nil {
// Did not find item in k8s
return nil, nil
}
fmt.Println("[debug] clusterIP:", k8sItem.Spec.ClusterIP)
for _, p := range k8sItem.Spec.Ports {
fmt.Println("[debug] host:", name)
fmt.Println("[debug] port:", p.Port)
}
clusterIP := k8sItem.Spec.ClusterIP
var records []msg.Service
for _, p := range k8sItem.Spec.Ports{
s := msg.Service{Host: clusterIP, Port: p.Port}
records = append(records, s)
}
return records, nil
}
/*
// Get performs the call to the Kubernetes http API.
func (g Kubernetes) Get(path string, recursive bool) (bool, error) {
fmt.Println("[debug] in Get path: ", path)
fmt.Println("[debug] in Get recursive: ", recursive)
return false, nil
}
*/
func (g Kubernetes) splitDNSName(name string) []string {
l := dns.SplitDomainName(name)
for i, j := 0, len(l)-1; i < j; i, j = i+1, j-1 {
l[i], l[j] = l[j], l[i]
}
return l
}
// skydns/local/skydns/east/staging/web
// skydns/local/skydns/west/production/web
//
// skydns/local/skydns/*/*/web
// skydns/local/skydns/*/web
// loopNodes recursively loops through the nodes and returns all the values. The nodes' keyname
// will be match against any wildcards when star is true.
/*
func (g Kubernetes) loopNodes(ns []*etcdc.Node, nameParts []string, star bool, bx map[msg.Service]bool) (sx []msg.Service, err error) {
if bx == nil {
bx = make(map[msg.Service]bool)
}
Nodes:
for _, n := range ns {
if n.Dir {
nodes, err := g.loopNodes(n.Nodes, nameParts, star, bx)
if err != nil {
return nil, err
}
sx = append(sx, nodes...)
continue
}
if star {
keyParts := strings.Split(n.Key, "/")
for i, n := range nameParts {
if i > len(keyParts)-1 {
// name is longer than key
continue Nodes
}
if n == "*" || n == "any" {
continue
}
if keyParts[i] != n {
continue Nodes
}
}
}
serv := new(msg.Service)
if err := json.Unmarshal([]byte(n.Value), serv); err != nil {
return nil, err
}
b := msg.Service{Host: serv.Host, Port: serv.Port, Priority: serv.Priority, Weight: serv.Weight, Text: serv.Text, Key: n.Key}
if _, ok := bx[b]; ok {
continue
}
bx[b] = true
serv.Key = n.Key
serv.Ttl = g.Ttl(n, serv)
if serv.Priority == 0 {
serv.Priority = priority
}
sx = append(sx, *serv)
}
return sx, nil
}
// Ttl returns the smaller of the kubernetes TTL and the service's
// TTL. If neither of these are set (have a zero value), a default is used.
func (g Kubernetes) Ttl(node *etcdc.Node, serv *msg.Service) uint32 {
kubernetesTtl := uint32(node.TTL)
if kubernetesTtl == 0 && serv.Ttl == 0 {
return ttl
}
if kubernetesTtl == 0 {
return serv.Ttl
}
if serv.Ttl == 0 {
return kubernetesTtl
}
if kubernetesTtl < serv.Ttl {
return kubernetesTtl
}
return serv.Ttl
}
*/
// kubernetesNameError checks if the error is ErrorCodeKeyNotFound from kubernetes.
func isKubernetesNameError(err error) bool {
return false
}
const (
priority = 10 // default priority when nothing is set
ttl = 300 // default ttl when nothing is set
minTtl = 60
hostmaster = "hostmaster"
k8sTimeout = 5 * time.Second
)
|
