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mw/kubernetes: Rewrite parseRequest and Readability improvements (#939)

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* mw/kubernetes: rewrite parseRequest

Stop looking at the qtype in parseRequest and make k.Namespace a map.
Fallout from this is that pkg/strings as it is not used anymore. Also
add a few helper functions to make unexposed namespaces easier to see in
the code.

Add wildcard tests to the middleware tests.

* Fix tests

Add a whole bunch of comments to document what we are trying to do.

* This is now answered

* up coverage

* duh

* Update testcase

* Make it nodata
This commit is contained in:
Miek Gieben 2017-08-22 20:44:42 +01:00 • committed by Yong Tang
parent 60d5e71a1a
commit 6a4e69eb9f
9 changed files with 189 additions and 168 deletions
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75
middleware/kubernetes/kubernetes.go
View file

@ -14,7 +14,6 @@ import (
"github.com/coredns/coredns/middleware/etcd/msg"
"github.com/coredns/coredns/middleware/pkg/dnsutil"
"github.com/coredns/coredns/middleware/pkg/healthcheck"
dnsstrings "github.com/coredns/coredns/middleware/pkg/strings"
"github.com/coredns/coredns/middleware/proxy"
"github.com/coredns/coredns/request"
@ -40,7 +39,7 @@ type Kubernetes struct {
APIClientKey string
APIConn dnsController
ResyncPeriod time.Duration
Namespaces []string
Namespaces map[string]bool
LabelSelector *unversionedapi.LabelSelector
Selector *labels.Selector
PodMode string
@ -56,7 +55,11 @@ type Kubernetes struct {
func New(zones []string) *Kubernetes {
k := new(Kubernetes)
k.Zones = zones
k.Namespaces = make(map[string]bool)
k.interfaceAddrsFunc = func() net.IP { return net.ParseIP("127.0.0.1") }
k.PodMode = PodModeDisabled
k.Proxy = proxy.Proxy{}
k.ResyncPeriod = defaultResyncPeriod
return k
}
@ -298,7 +301,7 @@ func (k *Kubernetes) Records(state request.Request, exact bool) ([]msg.Service,
return nil, e
}
if !k.namespaceExposed(r.namespace) {
if !wildcard(r.namespace) && !k.namespaceExposed(r.namespace) {
return nil, errNsNotExposed
}
@ -387,18 +390,17 @@ func (k *Kubernetes) findPods(namespace, podname string) (pods []kPod, err error
// PodModeVerified
objList := k.APIConn.PodIndex(ip)
nsWildcard := wildcard(namespace)
for _, o := range objList {
p, ok := o.(*api.Pod)
if !ok {
return nil, errAPIBadPodType
}
// If namespace has a wildcard, filter results against Corefile namespace list.
if nsWildcard && (len(k.Namespaces) > 0) && (!dnsstrings.StringInSlice(p.Namespace, k.Namespaces)) {
if wildcard(namespace) && !k.namespaceExposed(p.Namespace) {
continue
}
// check for matching ip and namespace
if ip == p.Status.PodIP && match(namespace, p.Namespace, nsWildcard) {
if ip == p.Status.PodIP && match(namespace, p.Namespace) {
s := kPod{name: podname, namespace: namespace, addr: ip}
pods = append(pods, s)
return pods, nil
@ -409,8 +411,8 @@ func (k *Kubernetes) findPods(namespace, podname string) (pods []kPod, err error
// get retrieves matching data from the cache.
func (k *Kubernetes) get(r recordRequest) (services []kService, pods []kPod, err error) {
switch {
case r.podOrSvc == Pod:
switch r.podOrSvc {
case Pod:
pods, err = k.findPods(r.namespace, r.service)
return nil, pods, err
default:
@ -423,19 +425,14 @@ func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
serviceList := k.APIConn.ServiceList()
var resultItems []kService
nsWildcard := wildcard(r.namespace)
serviceWildcard := wildcard(r.service)
portWildcard := wildcard(r.port) || r.port == ""
protocolWildcard := wildcard(r.protocol) || r.protocol == ""
for _, svc := range serviceList {
if !(match(r.namespace, svc.Namespace, nsWildcard) && match(r.service, svc.Name, serviceWildcard)) {
if !(match(r.namespace, svc.Namespace) && match(r.service, svc.Name)) {
continue
}
// If namespace has a wildcard, filter results against Corefile namespace list.
// (Namespaces without a wildcard were filtered before the call to this function.)
if nsWildcard && (len(k.Namespaces) > 0) && (!dnsstrings.StringInSlice(svc.Namespace, k.Namespaces)) {
if wildcard(r.namespace) && !k.namespaceExposed(svc.Namespace) {
continue
}
s := kService{name: svc.Name, namespace: svc.Namespace}
@ -448,14 +445,20 @@ func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
if ep.ObjectMeta.Name != svc.Name || ep.ObjectMeta.Namespace != svc.Namespace {
continue
}
for _, eps := range ep.Subsets {
for _, addr := range eps.Addresses {
for _, p := range eps.Ports {
ephostname := endpointHostname(addr)
if r.endpoint != "" && r.endpoint != ephostname {
// See comments in parse.go parseRequest about the endpoint handling.
if r.endpoint != "" {
if !match(r.endpoint, endpointHostname(addr)) {
continue
}
if !(match(r.port, p.Name, portWildcard) && match(r.protocol, string(p.Protocol), protocolWildcard)) {
}
for _, p := range eps.Ports {
if !(match(r.port, p.Name) && match(r.protocol, string(p.Protocol))) {
continue
}
s.endpoints = append(s.endpoints, endpoint{addr: addr, port: p})
@ -479,7 +482,7 @@ func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
// ClusterIP service
s.addr = svc.Spec.ClusterIP
for _, p := range svc.Spec.Ports {
if !(match(r.port, p.Name, portWildcard) && match(r.protocol, string(p.Protocol), protocolWildcard)) {
if !(match(r.port, p.Name) && match(r.protocol, string(p.Protocol))) {
continue
}
s.ports = append(s.ports, p)
@ -490,21 +493,30 @@ func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) {
return resultItems, nil
}
func match(a, b string, wildcard bool) bool {
if wildcard {
// match checks if a and b are equal taking wildcards into account.
func match(a, b string) bool {
if wildcard(a) {
return true
}
if wildcard(b) {
return true
}
return strings.EqualFold(a, b)
}
// getServiceRecordForIP: Gets a service record with a cluster ip matching the ip argument
// wildcard checks whether s contains a wildcard value defined as "*" or "any".
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) getServiceRecordForIP(ip, name string) []msg.Service {
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) && !dnsstrings.StringInSlice(service.Namespace, k.Namespaces) {
if (len(k.Namespaces) > 0) && !k.namespaceExposed(service.Namespace) {
continue
}
if service.Spec.ClusterIP == ip {
@ -515,7 +527,7 @@ func (k *Kubernetes) getServiceRecordForIP(ip, name string) []msg.Service {
// If no cluster ips match, search endpoints
epList := k.APIConn.EndpointsList()
for _, ep := range epList.Items {
if (len(k.Namespaces) > 0) && !dnsstrings.StringInSlice(ep.ObjectMeta.Namespace, k.Namespaces) {
if (len(k.Namespaces) > 0) && !k.namespaceExposed(ep.ObjectMeta.Namespace) {
continue
}
for _, eps := range ep.Subsets {
@ -532,20 +544,13 @@ func (k *Kubernetes) getServiceRecordForIP(ip, name string) []msg.Service {
// namespaceExposed returns true when the namespace is exposed.
func (k *Kubernetes) namespaceExposed(namespace string) bool {
// Abort if the namespace does not contain a wildcard, and namespace is
// not published per CoreFile Case where namespace contains a wildcard
// is handled in k.get(...) method.
if (!wildcard(namespace)) && (len(k.Namespaces) > 0) && (!dnsstrings.StringInSlice(namespace, k.Namespaces)) {
_, ok := k.Namespaces[namespace]
if len(k.Namespaces) > 0 && !ok {
return false
}
return true
}
// wildcard checks whether s contains a wildcard value
func wildcard(s string) bool {
return (s == "*" || s == "any")
}
const (
// Svc is the DNS schema for kubernetes services
Svc = "svc"