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Coredns
Commit 61fc672e authored by Miek Gieben's avatar Miek Gieben Committed by GitHub
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mw/kubernetes: remove kPod and kServices (#969) 

Based up on: #939, but redone in a new PR with some cherry-picked
commits:
aacb91ef0b927683b21d6ee39dbddbd001334854
5dc34247b7d0136d9fe035f6b10d6b3e14ee7f2c

This removes kPod and Kservice and creates []msg.Service from k.findPods
and k.findServices.

Updated few tests which I *think* are correct; they look correct to me.
parent 7f5086e9
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Inline Side-by-side
Showing with 110 additions and 153 deletions
middleware/kubernetes/federation.go
View file @ 61fc672e
......@@ -29,7 +29,7 @@ func (k *Kubernetes) Federations(state request.Request, fname, fzone string) (ms
if err != nil {
return msg.Service{}, err
}
r, err := k.parseRequest(state)
r, err := parseRequest(state)
lz := node.Labels[LabelZone]
lr := node.Labels[LabelRegion]
......
middleware/kubernetes/handler_test.go
View file @ 61fc672e
......@@ -47,7 +47,7 @@ var dnsTestCases = map[string](test.Case){
},
"SRV Service Not udp/tcp": {
Qname: "*._not-udp-or-tcp.svc1.testns.svc.cluster.local.", Qtype: dns.TypeSRV,
Rcode: dns.RcodeSuccess,
Rcode: dns.RcodeNameError,
Ns: []dns.RR{
test.SOA("cluster.local. 300 IN SOA ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 60"),
},
......@@ -92,7 +92,6 @@ var dnsTestCases = map[string](test.Case){
"AAAA Service (existing service)": {
Qname: "svc1.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
Rcode: dns.RcodeSuccess,
Answer: []dns.RR{},
Ns: []dns.RR{
test.SOA("cluster.local. 300 IN SOA ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 60"),
},
......@@ -100,7 +99,13 @@ var dnsTestCases = map[string](test.Case){
"AAAA Service (non-existing service)": {
Qname: "svc0.testns.svc.cluster.local.", Qtype: dns.TypeAAAA,
Rcode: dns.RcodeNameError,
Answer: []dns.RR{},
Ns: []dns.RR{
test.SOA("cluster.local. 300 IN SOA ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 60"),
},
},
"A Service (non-existing service)": {
Qname: "svc0.testns.svc.cluster.local.", Qtype: dns.TypeA,
Rcode: dns.RcodeNameError,
Ns: []dns.RR{
test.SOA("cluster.local. 300 IN SOA ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 60"),
},
......@@ -112,6 +117,20 @@ var dnsTestCases = map[string](test.Case){
test.TXT("dns-version.cluster.local 28800 IN TXT 1.0.1"),
},
},
"A Service (Headless) does not exist": {
Qname: "bogusendpoint.hdls1.testns.svc.cluster.local.", Qtype: dns.TypeA,
Rcode: dns.RcodeNameError,
Ns: []dns.RR{
test.SOA("cluster.local. 300 IN SOA ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 60"),
},
},
"A Service does not exist": {
Qname: "bogusendpoint.svc0.testns.svc.cluster.local.", Qtype: dns.TypeA,
Rcode: dns.RcodeNameError,
Ns: []dns.RR{
test.SOA("cluster.local. 300 IN SOA ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 60"),
},
},
}
var podModeDisabledCases = map[string](test.Case){
......
middleware/kubernetes/kubernetes.go
View file @ 61fc672e
......@@ -70,27 +70,6 @@ const (
DNSSchemaVersion = "1.0.1"
)
type endpoint struct {
addr api.EndpointAddress
port api.EndpointPort
}
// kService is a service as retrieved via the k8s API.
type kService struct {
name string
namespace string
addr string
ports []api.ServicePort
endpoints []endpoint
}
// kPod is a pod as retrieved via the k8s API.
type kPod struct {
name string
namespace string
addr string
}
var (
errNoItems = errors.New("no items found")
errNsNotExposed = errors.New("namespace is not exposed")
......@@ -286,7 +265,7 @@ func (k *Kubernetes) initKubeCache(opts dnsControlOpts) (err error) {
// Records looks up services in kubernetes.
func (k *Kubernetes) Records(state request.Request, exact bool) ([]msg.Service, error) {
r, e := k.parseRequest(state)
r, e := parseRequest(state)
if e != nil {
return nil, e
}
......@@ -295,16 +274,13 @@ func (k *Kubernetes) Records(state request.Request, exact bool) ([]msg.Service,
return nil, errNsNotExposed
}
services, pods, err := k.get(r)
if err != nil {
return nil, err
}
if len(services) == 0 && len(pods) == 0 {
return nil, errNoItems
if r.podOrSvc == Pod {
pods, err := k.findPods(r, state.Zone)
return pods, err
}
records := k.getRecordsForK8sItems(services, pods, state.Zone)
return records, nil
services, err := k.findServices(r, state.Zone)
return services, err
}
func endpointHostname(addr api.EndpointAddress) string {
......@@ -320,51 +296,17 @@ func endpointHostname(addr api.EndpointAddress) string {
return ""
}
func (k *Kubernetes) getRecordsForK8sItems(services []kService, pods []kPod, zone string) (records []msg.Service) {
zonePath := msg.Path(zone, "coredns")
for _, svc := range services {
if svc.addr == api.ClusterIPNone || len(svc.endpoints) > 0 {
// This is a headless service or endpoints are present, create records for each endpoint
for _, ep := range svc.endpoints {
s := msg.Service{Host: ep.addr.IP, Port: int(ep.port.Port)}
s.Key = strings.Join([]string{zonePath, Svc, svc.namespace, svc.name, endpointHostname(ep.addr)}, "/")
records = append(records, s)
}
continue
}
// Create records for each exposed port...
for _, p := range svc.ports {
s := msg.Service{Host: svc.addr, Port: int(p.Port)}
s.Key = strings.Join([]string{zonePath, Svc, svc.namespace, svc.name}, "/")
records = append(records, s)
}
// If the addr is not an IP (i.e. an external service), add the record ...
s := msg.Service{Key: strings.Join([]string{zonePath, Svc, svc.namespace, svc.name}, "/"), Host: svc.addr}
if t, _ := s.HostType(); t == dns.TypeCNAME {
s.Key = strings.Join([]string{zonePath, Svc, svc.namespace, svc.name}, "/")
records = append(records, s)
}
}
for _, p := range pods {
s := msg.Service{Key: strings.Join([]string{zonePath, Pod, p.namespace, p.name}, "/"), Host: p.addr}
records = append(records, s)
}
return records
}
func (k *Kubernetes) findPods(namespace, podname string) (pods []kPod, err error) {
func (k *Kubernetes) findPods(r recordRequest, zone string) (pods []msg.Service, err error) {
if k.podMode == podModeDisabled {
return pods, errPodsDisabled
return nil, errPodsDisabled
}
var ip string
namespace := r.namespace
podname := r.service
zonePath := msg.Path(zone, "coredns")
ip := ""
err = errNoItems
if strings.Count(podname, "-") == 3 && !strings.Contains(podname, "--") {
ip = strings.Replace(podname, "-", ".", -1)
} else {
......@@ -372,9 +314,7 @@ func (k *Kubernetes) findPods(namespace, podname string) (pods []kPod, err error
}
if k.podMode == podModeInsecure {
s := kPod{name: podname, namespace: namespace, addr: ip}
pods = append(pods, s)
return pods, nil
return []msg.Service{{Key: strings.Join([]string{zonePath, Pod, namespace, podname}, "/"), Host: ip}}, nil
}
// PodModeVerified
......@@ -391,29 +331,20 @@ func (k *Kubernetes) findPods(namespace, podname string) (pods []kPod, err error
}
// check for matching ip and namespace
if ip == p.Status.PodIP && match(namespace, p.Namespace) {
s := kPod{name: podname, namespace: namespace, addr: ip}
s := msg.Service{Key: strings.Join([]string{zonePath, Pod, namespace, podname}, "/"), Host: ip}
pods = append(pods, s)
return pods, nil
}
}
return pods, nil
}
// get retrieves matching data from the cache.
func (k *Kubernetes) get(r recordRequest) (services []kService, pods []kPod, err error) {
switch r.podOrSvc {
case Pod:
pods, err = k.findPods(r.namespace, r.service)
return nil, pods, err
default:
services, err = k.findServices(r)
return services, nil, err
err = nil
}
}
return pods, err
}
func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
// findServices returns the services matching r from the cache.
func (k *Kubernetes) findServices(r recordRequest, zone string) (services []msg.Service, err error) {
serviceList := k.APIConn.ServiceList()
var resultItems []kService
zonePath := msg.Path(zone, "coredns")
err = errNoItems // Set to errNoItems to signal really nothing found, gets reset when name is matched.
for _, svc := range serviceList {
if !(match(r.namespace, svc.Namespace) && match(r.service, svc.Name)) {
......@@ -425,11 +356,9 @@ func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
if wildcard(r.namespace) && !k.namespaceExposed(svc.Namespace) {
continue
}
s := kService{name: svc.Name, namespace: svc.Namespace}
// Endpoint query or headless service
if svc.Spec.ClusterIP == api.ClusterIPNone || r.endpoint != "" {
s.addr = svc.Spec.ClusterIP
endpointsList := k.APIConn.EndpointsList()
for _, ep := range endpointsList.Items {
if ep.ObjectMeta.Name != svc.Name || ep.ObjectMeta.Namespace != svc.Namespace {
......@@ -451,36 +380,47 @@ func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
if !(match(r.port, p.Name) && match(r.protocol, string(p.Protocol))) {
continue
}
s.endpoints = append(s.endpoints, endpoint{addr: addr, port: p})
}
s := msg.Service{Host: addr.IP, Port: int(p.Port)}
s.Key = strings.Join([]string{zonePath, Svc, svc.Namespace, svc.Name, endpointHostname(addr)}, "/")
err = nil
services = append(services, s)
}
}
}
if len(s.endpoints) > 0 {
resultItems = append(resultItems, s)
}
continue
}
// External service
if svc.Spec.ExternalName != "" {
s.addr = svc.Spec.ExternalName
resultItems = append(resultItems, s)
s := msg.Service{Key: strings.Join([]string{zonePath, Svc, svc.Namespace, svc.Name}, "/"), Host: svc.Spec.ExternalName}
if t, _ := s.HostType(); t == dns.TypeCNAME {
s.Key = strings.Join([]string{zonePath, Svc, svc.Namespace, svc.Name}, "/")
services = append(services, s)
err = nil
continue
}
}
// ClusterIP service
s.addr = svc.Spec.ClusterIP
for _, p := range svc.Spec.Ports {
if !(match(r.port, p.Name) && match(r.protocol, string(p.Protocol))) {
continue
}
s.ports = append(s.ports, p)
}
resultItems = append(resultItems, s)
err = nil
s := msg.Service{Host: svc.Spec.ClusterIP, Port: int(p.Port)}
s.Key = strings.Join([]string{zonePath, Svc, svc.Namespace, svc.Name}, "/")
services = append(services, s)
}
}
return resultItems, nil
return services, err
}
// match checks if a and b are equal taking wildcards into account.
......@@ -499,39 +439,6 @@ func wildcard(s string) bool {
return s == "*" || s == "any"
}
// serviceRecordForIP gets a service record with a cluster ip matching the ip argument
// If a service cluster ip does not match, it checks all endpoints
func (k *Kubernetes) serviceRecordForIP(ip, name string) []msg.Service {
// First check services with cluster ips
svcList := k.APIConn.ServiceList()
for _, service := range svcList {
if (len(k.Namespaces) > 0) && !k.namespaceExposed(service.Namespace) {
continue
}
if service.Spec.ClusterIP == ip {
domain := dnsutil.Join([]string{service.Name, service.Namespace, Svc, k.primaryZone()})
return []msg.Service{{Host: domain}}
}
}
// If no cluster ips match, search endpoints
epList := k.APIConn.EndpointsList()
for _, ep := range epList.Items {
if (len(k.Namespaces) > 0) && !k.namespaceExposed(ep.ObjectMeta.Namespace) {
continue
}
for _, eps := range ep.Subsets {
for _, addr := range eps.Addresses {
if addr.IP == ip {
domain := dnsutil.Join([]string{endpointHostname(addr), ep.ObjectMeta.Name, ep.ObjectMeta.Namespace, Svc, k.primaryZone()})
return []msg.Service{{Host: domain}}
}
}
}
}
return nil
}
// namespaceExposed returns true when the namespace is exposed.
func (k *Kubernetes) namespaceExposed(namespace string) bool {
_, ok := k.Namespaces[namespace]
......
middleware/kubernetes/parse.go
View file @ 61fc672e
......@@ -26,7 +26,7 @@ type recordRequest struct {
// parseRequest parses the qname to find all the elements we need for querying k8s. Anything
// that is not parsed will have the wildcard "*" value (except r.endpoint).
// Potential underscores are stripped from _port and _protocol.
func (k *Kubernetes) parseRequest(state request.Request) (r recordRequest, err error) {
func parseRequest(state request.Request) (r recordRequest, err error) {
// 3 Possible cases:
// 1. _port._protocol.service.namespace.pod|svc.zone
// 2. (endpoint): endpoint.service.namespace.pod|svc.zone
......
middleware/kubernetes/parse_test.go
View file @ 61fc672e
......@@ -9,8 +9,6 @@ import (
)
func TestParseRequest(t *testing.T) {
k := New([]string{zone})
tests := []struct {
query string
expected string // output from r.String()
......@@ -27,7 +25,7 @@ func TestParseRequest(t *testing.T) {
m.SetQuestion(tc.query, dns.TypeA)
state := request.Request{Zone: zone, Req: m}
r, e := k.parseRequest(state)
r, e := parseRequest(state)
if e != nil {
t.Errorf("Test %d, expected no error, got '%v'.", i, e)
}
......@@ -39,8 +37,6 @@ func TestParseRequest(t *testing.T) {
}
func TestParseInvalidRequest(t *testing.T) {
k := New([]string{zone})
invalid := []string{
"webs.mynamespace.pood.inter.webs.test.", // Request must be for pod or svc subdomain.
"too.long.for.what.I.am.trying.to.pod.inter.webs.tests.", // Too long.
......@@ -51,7 +47,7 @@ func TestParseInvalidRequest(t *testing.T) {
m.SetQuestion(query, dns.TypeA)
state := request.Request{Zone: zone, Req: m}
if _, e := k.parseRequest(state); e == nil {
if _, e := parseRequest(state); e == nil {
t.Errorf("Test %d: expected error from %s, got none", i, query)
}
}
......
middleware/kubernetes/reverse.go
View file @ 61fc672e
package kubernetes
import (
"strings"
"github.com/coredns/coredns/middleware"
"github.com/coredns/coredns/middleware/etcd/msg"
"github.com/coredns/coredns/middleware/pkg/dnsutil"
......@@ -18,3 +20,36 @@ func (k *Kubernetes) Reverse(state request.Request, exact bool, opt middleware.O
records := k.serviceRecordForIP(ip, state.Name())
return records, nil, nil
}
// serviceRecordForIP gets a service record with a cluster ip matching the ip argument
// If a service cluster ip does not match, it checks all endpoints
func (k *Kubernetes) serviceRecordForIP(ip, name string) []msg.Service {
// First check services with cluster ips
svcList := k.APIConn.ServiceList()
for _, service := range svcList {
if (len(k.Namespaces) > 0) && !k.namespaceExposed(service.Namespace) {
continue
}
if service.Spec.ClusterIP == ip {
domain := strings.Join([]string{service.Name, service.Namespace, Svc, k.primaryZone()}, ".")
return []msg.Service{{Host: domain}}
}
}
// If no cluster ips match, search endpoints
epList := k.APIConn.EndpointsList()
for _, ep := range epList.Items {
if (len(k.Namespaces) > 0) && !k.namespaceExposed(ep.ObjectMeta.Namespace) {
continue
}
for _, eps := range ep.Subsets {
for _, addr := range eps.Addresses {
if addr.IP == ip {
domain := strings.Join([]string{endpointHostname(addr), ep.ObjectMeta.Name, ep.ObjectMeta.Namespace, Svc, k.primaryZone()}, ".")
return []msg.Service{{Host: domain}}
}
}
}
}
return nil
}
test/kubernetes_test.go
View file @ 61fc672e
......@@ -214,7 +214,7 @@ var dnsTestCases = []test.Case{
},
{
Qname: "*._not-udp-or-tcp.svc-1-a.test-1.svc.cluster.local.", Qtype: dns.TypeSRV,
Rcode: dns.RcodeSuccess,
Rcode: dns.RcodeNameError,
Ns: []dns.RR{
test.SOA("cluster.local. 300 IN SOA ns.dns.cluster.local. hostmaster.cluster.local. 1499347823 7200 1800 86400 60"),
},
......
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