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Merge pull request #26226 from ArtfulCoder/reversedns 

Automatic merge from submit-queue

Added DNS Reverse Record logic for service IPs
pull/6/head
k8s-merge-robot 2016-06-02 18:43:39 -07:00
parent 0a2a7a9d6a 4224dbd6c6
commit 693dae70a8
3 changed files with 95 additions and 26 deletions
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42
pkg/dns/dns.go
View File

@ -49,6 +49,9 @@ const (
// A subdomain added to the user specified dmoain for all pods.
podSubdomain = "pod"
// arpaSuffix is the standard suffix for PTR IP reverse lookups.
arpaSuffix = ".in-addr.arpa."
// Resync period for the kube controller loop.
resyncPeriod = 5 * time.Minute
@ -78,6 +81,8 @@ type KubeDNS struct {
// A Records and SRV Records for (regular) services and headless Services.
cache *TreeCache
reverseRecordMap map[string]*skymsg.Service
// caller is responsible for using the cacheLock before invoking methods on cache
// the cache is not thread-safe, and the caller can guarantee thread safety by using
// the cacheLock
@ -109,6 +114,7 @@ func NewKubeDNS(client clientset.Interface, domain string, federations map[strin
domain: domain,
cache: NewTreeCache(),
cacheLock: sync.RWMutex{},
reverseRecordMap: make(map[string]*skymsg.Service),
domainPath: reverseArray(strings.Split(strings.TrimRight(domain, "."), ".")),
federations: federations,
}
@ -225,6 +231,7 @@ func (kd *KubeDNS) removeService(obj interface{}) {
kd.cacheLock.Lock()
defer kd.cacheLock.Unlock()
kd.cache.deletePath(subCachePath...)
delete(kd.reverseRecordMap, s.Spec.ClusterIP)
}
}
@ -283,9 +290,13 @@ func (kd *KubeDNS) newPortalService(service *kapi.Service) {
}
}
subCachePath := append(kd.domainPath, serviceSubdomain, service.Namespace)
host := kd.getServiceFQDN(service)
reverseRecord, _ := getSkyMsg(host, 0)
kd.cacheLock.Lock()
defer kd.cacheLock.Unlock()
kd.cache.setSubCache(service.Name, subCache, subCachePath...)
kd.reverseRecordMap[service.Spec.ClusterIP] = reverseRecord
}
func (kd *KubeDNS) generateRecordsForHeadlessService(e *kapi.Endpoints, svc *kapi.Service) error {
@ -430,17 +441,34 @@ func (kd *KubeDNS) Records(name string, exact bool) ([]skymsg.Service, error) {
func (kd *KubeDNS) ReverseRecord(name string) (*skymsg.Service, error) {
glog.Infof("Received ReverseRecord Request:%s", name)
segments := strings.Split(strings.TrimRight(name, "."), ".")
for _, k := range segments {
if k == "*" {
return nil, fmt.Errorf("reverse can not contain wildcards")
// if portalIP is not a valid IP, the reverseRecordMap lookup will fail
portalIP, ok := extractIP(name)
if !ok {
return nil, fmt.Errorf("does not support reverse lookup for %s", name)
}
kd.cacheLock.RLock()
defer kd.cacheLock.RUnlock()
if reverseRecord, ok := kd.reverseRecordMap[portalIP]; ok {
return reverseRecord, nil
}
return nil, fmt.Errorf("must be exactly one service record")
}
// extractIP turns a standard PTR reverse record lookup name
// into an IP address
func extractIP(reverseName string) (string, bool) {
if !strings.HasSuffix(reverseName, arpaSuffix) {
return "", false
}
search := strings.TrimSuffix(reverseName, arpaSuffix)
// reverse the segments and then combine them
segments := reverseArray(strings.Split(search, "."))
return strings.Join(segments, "."), true
}
// e.g {"local", "cluster", "pod", "default", "10-0-0-1"}
func (kd *KubeDNS) isPodRecord(path []string) bool {
if len(path) != len(kd.domainPath)+3 {
@ -602,6 +630,10 @@ func (kd *KubeDNS) getClusterZone() (string, error) {
return zone, nil
}
func (kd *KubeDNS) getServiceFQDN(service *kapi.Service) string {
return strings.Join([]string{service.Name, service.Namespace, serviceSubdomain, kd.domain}, ".")
}
func reverseArray(arr []string) []string {
for i := 0; i < len(arr)/2; i++ {
j := len(arr) - i - 1

19
pkg/dns/dns_test.go
View File

@ -45,6 +45,7 @@ func newKubeDNS() *KubeDNS {
endpointsStore: cache.NewStore(cache.MetaNamespaceKeyFunc),
servicesStore: cache.NewStore(cache.MetaNamespaceKeyFunc),
cache: NewTreeCache(),
reverseRecordMap: make(map[string]*skymsg.Service),
cacheLock: sync.RWMutex{},
domainPath: reverseArray(strings.Split(strings.TrimRight(testDomain, "."), ".")),
nodesStore: cache.NewStore(cache.MetaNamespaceKeyFunc),
@ -71,9 +72,11 @@ func TestUnnamedSinglePortService(t *testing.T) {
// Add the service
kd.newService(s)
assertDNSForClusterIP(t, kd, s)
assertReverseRecord(t, kd, s)
// Delete the service
kd.removeService(s)
assertNoDNSForClusterIP(t, kd, s)
assertNoReverseRecord(t, kd, s)
}
func TestNamedSinglePortService(t *testing.T) {
@ -457,6 +460,22 @@ func assertDNSForClusterIP(t *testing.T, kd *KubeDNS, s *kapi.Service) {
}
}
func assertReverseRecord(t *testing.T, kd *KubeDNS, s *kapi.Service) {
segments := reverseArray(strings.Split(s.Spec.ClusterIP, "."))
reverseLookup := fmt.Sprintf("%s%s", strings.Join(segments, "."), arpaSuffix)
reverseRecord, err := kd.ReverseRecord(reverseLookup)
require.NoError(t, err)
assert.Equal(t, kd.getServiceFQDN(s), reverseRecord.Host)
}
func assertNoReverseRecord(t *testing.T, kd *KubeDNS, s *kapi.Service) {
segments := reverseArray(strings.Split(s.Spec.ClusterIP, "."))
reverseLookup := fmt.Sprintf("%s%s", strings.Join(segments, "."), arpaSuffix)
reverseRecord, err := kd.ReverseRecord(reverseLookup)
require.Error(t, err)
require.Nil(t, reverseRecord)
}
func getEquivalentQueries(serviceFQDN, namespace string) []string {
return []string{
serviceFQDN,

34
test/e2e/dns.go
View File

@ -117,7 +117,7 @@ func createDNSPod(namespace, wheezyProbeCmd, jessieProbeCmd string, useAnnotatio
return dnsPod
}
func createProbeCommand(namesToResolve []string, hostEntries []string, fileNamePrefix, namespace string) (string, []string) {
func createProbeCommand(namesToResolve []string, hostEntries []string, ptrLookupIP string, fileNamePrefix, namespace string) (string, []string) {
fileNames := make([]string, 0, len(namesToResolve)*2)
probeCmd := "for i in `seq 1 600`; do "
for _, name := range namesToResolve {
@ -150,6 +150,16 @@ func createProbeCommand(namesToResolve []string, hostEntries []string, fileNameP
fileNames = append(fileNames, podARecByUDPFileName)
fileNames = append(fileNames, podARecByTCPFileName)
if len(ptrLookupIP) > 0 {
ptrLookup := fmt.Sprintf("%s.in-addr.arpa.", strings.Join(reverseArray(strings.Split(ptrLookupIP, ".")), "."))
ptrRecByUDPFileName := fmt.Sprintf("%s_udp@PTR", ptrLookupIP)
ptrRecByTCPFileName := fmt.Sprintf("%s_tcp@PTR", ptrLookupIP)
probeCmd += fmt.Sprintf(`test -n "$$(dig +notcp +noall +answer +search %s PTR)" && echo OK > /results/%s;`, ptrLookup, ptrRecByUDPFileName)
probeCmd += fmt.Sprintf(`test -n "$$(dig +tcp +noall +answer +search %s PTR)" && echo OK > /results/%s;`, ptrLookup, ptrRecByTCPFileName)
fileNames = append(fileNames, ptrRecByUDPFileName)
fileNames = append(fileNames, ptrRecByTCPFileName)
}
probeCmd += "sleep 1; done"
return probeCmd, fileNames
}
@ -256,6 +266,14 @@ func createServiceSpec(serviceName string, isHeadless bool, selector map[string]
return headlessService
}
func reverseArray(arr []string) []string {
for i := 0; i < len(arr)/2; i++ {
j := len(arr) - i - 1
arr[i], arr[j] = arr[j], arr[i]
}
return arr
}
var _ = framework.KubeDescribe("DNS", func() {
f := framework.NewDefaultFramework("dns")
@ -274,8 +292,8 @@ var _ = framework.KubeDescribe("DNS", func() {
}
hostFQDN := fmt.Sprintf("%s.%s.%s.svc.cluster.local", dnsTestPodHostName, dnsTestServiceName, f.Namespace.Name)
hostEntries := []string{hostFQDN, dnsTestPodHostName}
wheezyProbeCmd, wheezyFileNames := createProbeCommand(namesToResolve, hostEntries, "wheezy", f.Namespace.Name)
jessieProbeCmd, jessieFileNames := createProbeCommand(namesToResolve, hostEntries, "jessie", f.Namespace.Name)
wheezyProbeCmd, wheezyFileNames := createProbeCommand(namesToResolve, hostEntries, "", "wheezy", f.Namespace.Name)
jessieProbeCmd, jessieFileNames := createProbeCommand(namesToResolve, hostEntries, "", "jessie", f.Namespace.Name)
By("Running these commands on wheezy:" + wheezyProbeCmd + "\n")
By("Running these commands on jessie:" + jessieProbeCmd + "\n")
@ -301,7 +319,7 @@ var _ = framework.KubeDescribe("DNS", func() {
}()
regularService := createServiceSpec("test-service-2", false, testServiceSelector)
_, err = f.Client.Services(f.Namespace.Name).Create(regularService)
regularService, err = f.Client.Services(f.Namespace.Name).Create(regularService)
Expect(err).NotTo(HaveOccurred())
defer func() {
By("deleting the test service")
@ -320,8 +338,8 @@ var _ = framework.KubeDescribe("DNS", func() {
fmt.Sprintf("_http._tcp.%s.%s.svc", regularService.Name, f.Namespace.Name),
}
wheezyProbeCmd, wheezyFileNames := createProbeCommand(namesToResolve, nil, "wheezy", f.Namespace.Name)
jessieProbeCmd, jessieFileNames := createProbeCommand(namesToResolve, nil, "jessie", f.Namespace.Name)
wheezyProbeCmd, wheezyFileNames := createProbeCommand(namesToResolve, nil, regularService.Spec.ClusterIP, "wheezy", f.Namespace.Name)
jessieProbeCmd, jessieFileNames := createProbeCommand(namesToResolve, nil, regularService.Spec.ClusterIP, "jessie", f.Namespace.Name)
By("Running these commands on wheezy:" + wheezyProbeCmd + "\n")
By("Running these commands on jessie:" + jessieProbeCmd + "\n")
@ -353,8 +371,8 @@ var _ = framework.KubeDescribe("DNS", func() {
hostFQDN := fmt.Sprintf("%s.%s.%s.svc.cluster.local", podHostname, serviceName, f.Namespace.Name)
hostNames := []string{hostFQDN, podHostname}
namesToResolve := []string{hostFQDN}
wheezyProbeCmd, wheezyFileNames := createProbeCommand(namesToResolve, hostNames, "wheezy", f.Namespace.Name)
jessieProbeCmd, jessieFileNames := createProbeCommand(namesToResolve, hostNames, "jessie", f.Namespace.Name)
wheezyProbeCmd, wheezyFileNames := createProbeCommand(namesToResolve, hostNames, "", "wheezy", f.Namespace.Name)
jessieProbeCmd, jessieFileNames := createProbeCommand(namesToResolve, hostNames, "", "jessie", f.Namespace.Name)
By("Running these commands on wheezy:" + wheezyProbeCmd + "\n")
By("Running these commands on jessie:" + jessieProbeCmd + "\n")