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plugin/kubernetes: Handle multiple local IPs and bind (#3208)

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* use all local IPs

* mult/bind ips

* gofmt + boundIPs fix

* fix no matching endpoint case

* don't duplicate NS records in answer

* fix answer dedup

* fix comment

* add multi local ip test case
This commit is contained in:
Chris O'Haver 2019-09-05 09:07:55 -04:00 • committed by GitHub
parent d79562842a
commit 630d3d60b9
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GPG key ID: 4AEE18F83AFDEB23
8 changed files with 91 additions and 51 deletions
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9
plugin/backend_lookup.go
View file

@ -372,6 +372,8 @@ func NS(ctx context.Context, b ServiceBackend, zone string, state request.Reques
// ... and reset
state.Req.Question[0].Name = old
seen := map[string]bool{}
for _, serv := range services {
what, ip := serv.HostType()
switch what {
@ -380,8 +382,13 @@ func NS(ctx context.Context, b ServiceBackend, zone string, state request.Reques
case dns.TypeA, dns.TypeAAAA:
serv.Host = msg.Domain(serv.Key)
records = append(records, serv.NewNS(state.QName()))
extra = append(extra, newAddress(serv, serv.Host, ip, what))
ns := serv.NewNS(state.QName())
if _, ok := seen[ns.Ns]; ok {
continue
}
seen[ns.Ns] = true
records = append(records, ns)
}
}
return records, extra, nil

4
plugin/kubernetes/kubernetes.go
View file

@ -43,9 +43,8 @@ type Kubernetes struct {
Fall fall.F
ttl uint32
opts dnsControlOpts
primaryZoneIndex int
interfaceAddrsFunc func() net.IP
localIPs []net.IP
autoPathSearch []string // Local search path from /etc/resolv.conf. Needed for autopath.
TransferTo []string
}
@ -56,7 +55,6 @@ func New(zones []string) *Kubernetes {
k := new(Kubernetes)
k.Zones = zones
k.Namespaces = make(map[string]struct{})
k.interfaceAddrsFunc = func() net.IP { return net.ParseIP("127.0.0.1") }
k.podMode = podModeDisabled
k.ttl = defaultTTL

4
plugin/kubernetes/kubernetes_apex_test.go
View file

@ -2,6 +2,7 @@ package kubernetes
import (
"context"
"net"
"testing"
"github.com/coredns/coredns/plugin/pkg/dnstest"
@ -63,6 +64,7 @@ func TestServeDNSApex(t *testing.T) {
k := New([]string{"cluster.local."})
k.APIConn = &APIConnServeTest{}
k.Next = test.NextHandler(dns.RcodeSuccess, nil)
k.localIPs = []net.IP{net.ParseIP("127.0.0.1")}
ctx := context.TODO()
for i, tc := range kubeApexCases {
@ -85,7 +87,7 @@ func TestServeDNSApex(t *testing.T) {
}
if err := test.SortAndCheck(resp, tc); err != nil {
t.Error(err)
t.Errorf("Test %d: %v", i, err)
}
}
}

34
plugin/kubernetes/kubernetes_test.go
View file

@ -310,20 +310,28 @@ func TestServicesAuthority(t *testing.T) {
key string
}
type svcTest struct {
interfaceAddrs func() net.IP
localIPs []net.IP
qname string
qtype uint16
answer *svcAns
answer []svcAns
}
tests := []svcTest{
{interfaceAddrs: func() net.IP { return net.ParseIP("127.0.0.1") }, qname: "ns.dns.interwebs.test.", qtype: dns.TypeA, answer: &svcAns{host: "127.0.0.1", key: "/" + coredns + "/test/interwebs/dns/ns"}},
{interfaceAddrs: func() net.IP { return net.ParseIP("127.0.0.1") }, qname: "ns.dns.interwebs.test.", qtype: dns.TypeAAAA},
{interfaceAddrs: func() net.IP { return net.ParseIP("::1") }, qname: "ns.dns.interwebs.test.", qtype: dns.TypeA},
{interfaceAddrs: func() net.IP { return net.ParseIP("::1") }, qname: "ns.dns.interwebs.test.", qtype: dns.TypeAAAA, answer: &svcAns{host: "::1", key: "/" + coredns + "/test/interwebs/dns/ns"}},
{localIPs: []net.IP{net.ParseIP("1.2.3.4")}, qname: "ns.dns.interwebs.test.", qtype: dns.TypeA, answer: []svcAns{{host: "1.2.3.4", key: "/" + coredns + "/test/interwebs/dns/ns"}}},
{localIPs: []net.IP{net.ParseIP("1.2.3.4")}, qname: "ns.dns.interwebs.test.", qtype: dns.TypeAAAA},
{localIPs: []net.IP{net.ParseIP("1:2::3:4")}, qname: "ns.dns.interwebs.test.", qtype: dns.TypeA},
{localIPs: []net.IP{net.ParseIP("1:2::3:4")}, qname: "ns.dns.interwebs.test.", qtype: dns.TypeAAAA, answer: []svcAns{{host: "1:2::3:4", key: "/" + coredns + "/test/interwebs/dns/ns"}}},
{
localIPs: []net.IP{net.ParseIP("1.2.3.4"), net.ParseIP("1:2::3:4")},
qname: "ns.dns.interwebs.test.",
qtype: dns.TypeNS, answer: []svcAns{
{host: "1.2.3.4", key: "/" + coredns + "/test/interwebs/dns/ns"},
{host: "1:2::3:4", key: "/" + coredns + "/test/interwebs/dns/ns"},
},
},
}
for i, test := range tests {
k.interfaceAddrsFunc = test.interfaceAddrs
k.localIPs = test.localIPs
state := request.Request{
Req: &dns.Msg{Question: []dns.Question{{Name: test.qname, Qtype: test.qtype}}},
@ -334,7 +342,7 @@ func TestServicesAuthority(t *testing.T) {
t.Errorf("Test %d: got error '%v'", i, e)
continue
}
if test.answer != nil && len(svcs) != 1 {
if test.answer != nil && len(svcs) != len(test.answer) {
t.Errorf("Test %d, expected 1 answer, got %v", i, len(svcs))
continue
}
@ -347,11 +355,13 @@ func TestServicesAuthority(t *testing.T) {
continue
}
if test.answer.host != svcs[0].Host {
t.Errorf("Test %d, expected host '%v', got '%v'", i, test.answer.host, svcs[0].Host)
for i, answer := range test.answer {
if answer.host != svcs[i].Host {
t.Errorf("Test %d, expected host '%v', got '%v'", i, answer.host, svcs[i].Host)
}
if answer.key != svcs[i].Key {
t.Errorf("Test %d, expected key '%v', got '%v'", i, answer.key, svcs[i].Key)
}
if test.answer.key != svcs[0].Key {
t.Errorf("Test %d, expected key '%v', got '%v'", i, test.answer.key, svcs[0].Key)
}
}
}

31
plugin/kubernetes/local.go
View file

@ -2,36 +2,48 @@ package kubernetes
import (
"net"
"github.com/caddyserver/caddy"
"github.com/coredns/coredns/core/dnsserver"
)
func localPodIP() net.IP {
// boundIPs returns the list of non-loopback IPs that CoreDNS is bound to
func boundIPs(c *caddy.Controller) (ips []net.IP) {
conf := dnsserver.GetConfig(c)
hosts := conf.ListenHosts
if hosts == nil || hosts[0] == "" {
hosts = nil
addrs, err := net.InterfaceAddrs()
if err != nil {
return nil
}
for _, addr := range addrs {
ip, _, _ := net.ParseCIDR(addr.String())
hosts = append(hosts, addr.String())
}
}
for _, host := range hosts {
ip, _, _ := net.ParseCIDR(host)
ip4 := ip.To4()
if ip4 != nil && !ip4.IsLoopback() {
return ip4
ips = append(ips, ip4)
continue
}
ip6 := ip.To16()
if ip6 != nil && !ip6.IsLoopback() {
return ip6
ips = append(ips, ip6)
}
}
return nil
return ips
}
// LocalNodeName is exclusively used in federation plugin, will be deprecated later.
func (k *Kubernetes) LocalNodeName() string {
localIP := k.interfaceAddrsFunc()
if localIP == nil {
if len(k.localIPs) == 0 {
return ""
}
// Find endpoint matching localIP
// Find fist endpoint matching any localIP
for _, localIP := range k.localIPs {
for _, ep := range k.APIConn.EpIndexReverse(localIP.String()) {
for _, eps := range ep.Subsets {
for _, addr := range eps.Addresses {
@ -41,5 +53,6 @@ func (k *Kubernetes) LocalNodeName() string {
}
}
}
}
return ""
}

19
plugin/kubernetes/ns.go
View file

@ -21,15 +21,10 @@ func (k *Kubernetes) nsAddrs(external bool, zone string) []dns.RR {
svcIPs []net.IP
)
// Find the CoreDNS Endpoint
localIP := k.interfaceAddrsFunc()
// Find the CoreDNS Endpoints
for _, localIP := range k.localIPs {
endpoints := k.APIConn.EpIndexReverse(localIP.String())
// If the CoreDNS Endpoint is not found, use the locally bound IP address
if len(endpoints) == 0 {
svcNames = []string{defaultNSName + zone}
svcIPs = []net.IP{localIP}
} else {
// Collect IPs for all Services of the Endpoints
for _, endpoint := range endpoints {
svcs := k.APIConn.SvcIndex(object.ServiceKey(endpoint.Name, endpoint.Namespace))
@ -59,6 +54,16 @@ func (k *Kubernetes) nsAddrs(external bool, zone string) []dns.RR {
}
}
// If no local IPs matched any endpoints, use the localIPs directly
if len(svcIPs) == 0 {
svcIPs = make([]net.IP, len(k.localIPs))
svcNames = make([]string, len(k.localIPs))
for i, localIP := range k.localIPs {
svcNames[i] = defaultNSName + zone
svcIPs[i] = localIP
}
}
// Create an RR slice of collected IPs
var rrs []dns.RR
rrs = make([]dns.RR, len(svcIPs))

2
plugin/kubernetes/ns_test.go
View file

@ -111,7 +111,7 @@ func TestNsAddrs(t *testing.T) {
k := New([]string{"inter.webs.test."})
k.APIConn = &APIConnTest{}
k.interfaceAddrsFunc = func() net.IP { return net.ParseIP("10.244.0.20") }
k.localIPs = []net.IP{net.ParseIP("10.244.0.20")}
cdrs := k.nsAddrs(false, k.Zones[0])

7
plugin/kubernetes/setup.go
View file

@ -61,6 +61,12 @@ func setup(c *caddy.Controller) error {
return k
})
// get locally bound addresses
c.OnStartup(func() error {
k.localIPs = boundIPs(c)
return nil
})
return nil
}
@ -113,7 +119,6 @@ func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
func ParseStanza(c *caddy.Controller) (*Kubernetes, error) {
k8s := New([]string{""})
k8s.interfaceAddrsFunc = localPodIP
k8s.autoPathSearch = searchFromResolvConf()
opts := dnsControlOpts{