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mw/k8s: remove dependence on global var (#888)

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* mw/k8s: remove dependence on global var

Remove the global coreDNSRecord that was used. Remove tests the
referenced that var. Cleanup the rest.

* Rename function as well

* fixes
This commit is contained in:
Miek Gieben 2017-08-10 23:13:08 +01:00 • committed by GitHub
parent c65fdb5fc3
commit acfa6501e0
3 changed files with 51 additions and 92 deletions
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2
middleware/kubernetes/kubernetes.go
View file

@ -112,7 +112,7 @@ func (k *Kubernetes) Services(state request.Request, exact bool, opt middleware.
return []msg.Service{svc}, nil, nil
case dns.TypeNS:
// We can only get here if the qname equal the zone, see ServeDNS in handler.go.
ns := k.coreDNSRecord()
ns := k.nsAddr()
svc := msg.Service{Host: ns.A.String(), Key: msg.Path(state.QName(), "coredns")}
return []msg.Service{svc}, nil, nil
}

38
middleware/kubernetes/ns.go
View file

@ -10,15 +10,11 @@ import (
"k8s.io/client-go/1.5/pkg/api"
)
const defaultNSName = "ns.dns."
var corednsRecord dns.A
// DefaultNSMsg returns an msg.Service representing an A record for
// ns.dns.[zone] -> dns service ip. This A record is needed to legitimize
// the SOA response in middleware.NS(), which is hardcoded at ns.dns.[zone].
func (k *Kubernetes) defaultNSMsg(r recordRequest) msg.Service {
ns := k.coreDNSRecord()
ns := k.nsAddr()
s := msg.Service{
Key: msg.Path(strings.Join([]string{defaultNSName, r.zone}, "."), "coredns"),
Host: ns.A.String(),
@ -30,19 +26,18 @@ func isDefaultNS(name string, r recordRequest) bool {
return strings.Index(name, defaultNSName) == 0 && strings.Index(name, r.zone) == len(defaultNSName)
}
func (k *Kubernetes) coreDNSRecord() dns.A {
func (k *Kubernetes) nsAddr() *dns.A {
var (
svcName string
svcNamespace string
dnsIP net.IP
)
if len(corednsRecord.Hdr.Name) == 0 || corednsRecord.A == nil {
// get local Pod IP
rr := new(dns.A)
localIP := k.interfaceAddrsFunc()
// Find endpoint matching IP to get service and namespace
endpointsList := k.APIConn.EndpointsList()
rr.A = localIP
FindEndpoint:
for _, ep := range endpointsList.Items {
for _, eps := range ep.Subsets {
@ -58,29 +53,28 @@ func (k *Kubernetes) coreDNSRecord() dns.A {
}
if len(svcName) == 0 {
corednsRecord.Hdr.Name = defaultNSName
corednsRecord.A = localIP
return corednsRecord
rr.Hdr.Name = defaultNSName
rr.A = localIP
return rr
}
// Find service to get ClusterIP
serviceList := k.APIConn.ServiceList()
FindService:
for _, svc := range serviceList {
if svcName == svc.Name && svcNamespace == svc.Namespace {
if svc.Spec.ClusterIP == api.ClusterIPNone {
dnsIP = localIP
rr.A = localIP
} else {
dnsIP = net.ParseIP(svc.Spec.ClusterIP)
rr.A = net.ParseIP(svc.Spec.ClusterIP)
}
break FindService
}
}
if dnsIP == nil {
dnsIP = localIP
rr.Hdr.Name = strings.Join([]string{svcName, svcNamespace, "svc."}, ".")
return rr
}
corednsRecord.Hdr.Name = strings.Join([]string{svcName, svcNamespace, "svc."}, ".")
corednsRecord.A = dnsIP
}
return corednsRecord
}
const defaultNSName = "ns.dns."

53
middleware/kubernetes/ns_test.go
View file

@ -1,42 +1,11 @@
package kubernetes
import "testing"
import "net"
import (
"net"
"testing"
import "k8s.io/client-go/1.5/pkg/api"
import "github.com/miekg/dns"
func TestDefaultNSMsg(t *testing.T) {
k := Kubernetes{Zones: []string{"inter.webs.test."}}
corednsRecord.Hdr.Name = "coredns.kube-system."
corednsRecord.A = net.IP("1.2.3.4")
r, _ := k.parseRequest("ns.dns.inter.webs.test.", dns.TypeA, "inter.webs.test.")
expected := "/coredns/test/webs/inter/dns/ns"
svc := k.defaultNSMsg(r)
if svc.Key != expected {
t.Errorf("Expected result '%v'. Instead got result '%v'.", expected, svc.Key)
}
}
func TestIsDefaultNS(t *testing.T) {
k := Kubernetes{Zones: []string{"inter.webs.test."}}
r, _ := k.parseRequest("ns.dns.inter.webs.test", dns.TypeA, "inter.webs.test.")
var name string
var expected bool
name = "ns.dns.inter.webs.test."
expected = true
if isDefaultNS(name, r) != expected {
t.Errorf("Expected IsDefaultNS('%v') to be '%v'.", name, expected)
}
name = "ns.dns.blah.inter.webs.test"
expected = false
if isDefaultNS(name, r) != expected {
t.Errorf("Expected IsDefaultNS('%v') to be '%v'.", name, expected)
}
}
"k8s.io/client-go/1.5/pkg/api"
)
type APIConnTest struct{}
@ -83,24 +52,20 @@ func (APIConnTest) EndpointsList() api.EndpointsList {
func (APIConnTest) GetNodeByName(name string) (api.Node, error) { return api.Node{}, nil }
func TestDoCoreDNSRecord(t *testing.T) {
func TestNsAddr(t *testing.T) {
corednsRecord = dns.A{}
k := Kubernetes{Zones: []string{"inter.webs.test"}}
k.interfaceAddrsFunc = func() net.IP { return net.ParseIP("172.0.40.10") }
k.APIConn = &APIConnTest{}
cdr := k.coreDNSRecord()
cdr := k.nsAddr()
expected := "10.0.0.111"
if cdr.A.String() != expected {
t.Errorf("Expected A to be '%v', got '%v'", expected, cdr.A.String())
t.Errorf("Expected A to be %q, got %q", expected, cdr.A.String())
}
expected = "dns-service.kube-system.svc."
if cdr.Hdr.Name != expected {
t.Errorf("Expected Hdr.Name to be '%v', got '%v'", expected, cdr.Hdr.Name)
t.Errorf("Expected Hdr.Name to be %q, got %q", expected, cdr.Hdr.Name)
}
}