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plugin/kubernetes: fix headless/endpoint query panics when endpoints are disabled (#6137)

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* always create listers, so we dont panic

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>

---------

Signed-off-by: Chris O'Haver <cohaver@infoblox.com>
This commit is contained in:
Chris O'Haver 2023-06-07 16:22:28 -04:00 • committed by GitHub
parent 7bf37c1da0
commit 6d3db023fe
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2 changed files with 119 additions and 50 deletions
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117
plugin/kubernetes/controller_test.go
View file

@ -1,16 +1,19 @@
package kubernetes
package kubernetes
import (
"context"
"net"
"strconv"
"testing"
"time"
"github.com/coredns/coredns/plugin/kubernetes/object"
"github.com/coredns/coredns/plugin/pkg/dnstest"
"github.com/coredns/coredns/plugin/test"
"github.com/miekg/dns"
api "k8s.io/api/core/v1"
discovery "k8s.io/api/discovery/v1"
meta "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/kubernetes/fake"
@ -25,23 +28,39 @@ func inc(ip net.IP) {
}
}
func BenchmarkController(b *testing.B) {
func kubernetesWithFakeClient(ctx context.Context, zone, cidr string, initEndpointsCache bool, svcType string) *Kubernetes {
client := fake.NewSimpleClientset()
dco := dnsControlOpts{
zones: []string{"cluster.local."},
zones: []string{zone},
initEndpointsCache: initEndpointsCache,
}
ctx := context.Background()
controller := newdnsController(ctx, client, dco)
cidr := "10.0.0.0/19"
// Add resources
generateEndpoints(cidr, client)
generateSvcs(cidr, "all", client)
m := new(dns.Msg)
m.SetQuestion("svc1.testns.svc.cluster.local.", dns.TypeA)
_, err := client.CoreV1().Namespaces().Create(ctx, &api.Namespace{ObjectMeta: meta.ObjectMeta{Name: "testns"}}, meta.CreateOptions{})
if err != nil {
log.Fatal(err)
}
generateSvcs(cidr, svcType, client)
generateEndpointSlices(cidr, client)
k := New([]string{"cluster.local."})
k.APIConn = controller
return k
}
func BenchmarkController(b *testing.B) {
ctx := context.Background()
k := kubernetesWithFakeClient(ctx, "cluster.local.", "10.0.0.0/24", true, "all")
go k.APIConn.Run()
defer k.APIConn.Stop()
for !k.APIConn.HasSynced() {
time.Sleep(time.Millisecond)
}
rw := &test.ResponseWriter{}
m := new(dns.Msg)
m.SetQuestion("svc1.testns.svc.cluster.local.", dns.TypeA)
b.ResetTimer()
for i := 0; i < b.N; i++ {
@ -49,7 +68,47 @@ func BenchmarkController(b *testing.B) {
}
}
func generateEndpoints(cidr string, client kubernetes.Interface) {
func TestEndpointsDisabled(t *testing.T) {
ctx := context.Background()
k := kubernetesWithFakeClient(ctx, "cluster.local.", "10.0.0.0/30", false, "headless")
k.opts.initEndpointsCache = false
go k.APIConn.Run()
defer k.APIConn.Stop()
for !k.APIConn.HasSynced() {
time.Sleep(time.Millisecond)
}
rw := &dnstest.Recorder{ResponseWriter: &test.ResponseWriter{}}
m := new(dns.Msg)
m.SetQuestion("svc2.testns.svc.cluster.local.", dns.TypeA)
k.ServeDNS(ctx, rw, m)
if rw.Msg.Rcode != dns.RcodeNameError {
t.Errorf("Expected NXDOMAIN, got %v", dns.RcodeToString[rw.Msg.Rcode])
}
}
func TestEndpointsEnabled(t *testing.T) {
ctx := context.Background()
k := kubernetesWithFakeClient(ctx, "cluster.local.", "10.0.0.0/30", true, "headless")
k.opts.initEndpointsCache = true
go k.APIConn.Run()
defer k.APIConn.Stop()
for !k.APIConn.HasSynced() {
time.Sleep(time.Millisecond)
}
rw := &dnstest.Recorder{ResponseWriter: &test.ResponseWriter{}}
m := new(dns.Msg)
m.SetQuestion("svc2.testns.svc.cluster.local.", dns.TypeA)
k.ServeDNS(ctx, rw, m)
if rw.Msg.Rcode != dns.RcodeSuccess {
t.Errorf("Expected SUCCESS, got %v", dns.RcodeToString[rw.Msg.Rcode])
}
}
func generateEndpointSlices(cidr string, client kubernetes.Interface) {
// https://groups.google.com/d/msg/golang-nuts/zlcYA4qk-94/TWRFHeXJCcYJ
ip, ipnet, err := net.ParseCIDR(cidr)
if err != nil {
@ -57,30 +116,36 @@ func generateEndpoints(cidr string, client kubernetes.Interface) {
}
count := 1
ep := &api.Endpoints{
Subsets: []api.EndpointSubset{{
Ports: []api.EndpointPort{
{
Port: 80,
Protocol: "tcp",
Name: "http",
},
port := int32(80)
protocol := api.Protocol("tcp")
name := "http"
eps := &discovery.EndpointSlice{
Ports: []discovery.EndpointPort{
{
Port: &port,
Protocol: &protocol,
Name: &name,
},
}},
},
ObjectMeta: meta.ObjectMeta{
Namespace: "testns",
},
}
ctx := context.TODO()
for ip := ip.Mask(ipnet.Mask); ipnet.Contains(ip); inc(ip) {
ep.Subsets[0].Addresses = []api.EndpointAddress{
hostname := "foo" + strconv.Itoa(count)
eps.Endpoints = []discovery.Endpoint{
{
IP: ip.String(),
Hostname: "foo" + strconv.Itoa(count),
Addresses: []string{ip.String()},
Hostname: &hostname,
},
}
ep.ObjectMeta.Name = "svc" + strconv.Itoa(count)
client.CoreV1().Endpoints("testns").Create(ctx, ep, meta.CreateOptions{})
eps.ObjectMeta.Name = "svc" + strconv.Itoa(count)
eps.ObjectMeta.Labels = map[string]string{discovery.LabelServiceName: eps.ObjectMeta.Name}
_, err := client.DiscoveryV1().EndpointSlices("testns").Create(ctx, eps, meta.CreateOptions{})
if err != nil {
log.Fatal(err)
}
count++
}
}
@ -144,7 +209,7 @@ func createHeadlessSvc(suffix int, client kubernetes.Interface, ip net.IP) {
ctx := context.TODO()
client.CoreV1().Services("testns").Create(ctx, &api.Service{
ObjectMeta: meta.ObjectMeta{
Name: "hdls" + strconv.Itoa(suffix),
Name: "svc" + strconv.Itoa(suffix),
Namespace: "testns",
},
Spec: api.ServiceSpec{
@ -157,7 +222,7 @@ func createExternalSvc(suffix int, client kubernetes.Interface, ip net.IP) {
ctx := context.TODO()
client.CoreV1().Services("testns").Create(ctx, &api.Service{
ObjectMeta: meta.ObjectMeta{
Name: "external" + strconv.Itoa(suffix),
Name: "svc" + strconv.Itoa(suffix),
Namespace: "testns",
},
Spec: api.ServiceSpec{