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middleware/kubernetes: Server side path lookups (#750)

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* initial commit

* add config options

* add readme

* rewording

* revert unlreated change

* normalize host domain path

* add ndots opt, allow > 1 host domains, pull host domains from resolv.conf

* implementing review feedback

* update readme

* use dns lib, config format, defaults

* Correct autopath example.
This commit is contained in:
Chris O'Haver 2017-06-28 18:44:30 -04:00 • committed by John Belamaric
parent 817f3960b8
commit edf71fb168
6 changed files with 407 additions and 51 deletions
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71
middleware/kubernetes/kubernetes.go
View file

@ -28,26 +28,35 @@ import (
// Kubernetes implements a middleware that connects to a Kubernetes cluster.
type Kubernetes struct {
Next middleware.Handler
Zones []string
primaryZone int
Proxy proxy.Proxy // Proxy for looking up names during the resolution process
APIEndpoint string
APICertAuth string
APIClientCert string
APIClientKey string
APIConn dnsController
ResyncPeriod time.Duration
Namespaces []string
Federations []Federation
LabelSelector *unversionedapi.LabelSelector
Selector *labels.Selector
PodMode string
ReverseCidrs []net.IPNet
Fallthrough bool
Next middleware.Handler
Zones []string
primaryZone int
Proxy proxy.Proxy // Proxy for looking up names during the resolution process
APIEndpoint string
APICertAuth string
APIClientCert string
APIClientKey string
APIConn dnsController
ResyncPeriod time.Duration
Namespaces []string
Federations []Federation
LabelSelector *unversionedapi.LabelSelector
Selector *labels.Selector
PodMode string
ReverseCidrs []net.IPNet
Fallthrough bool
AutoPath
interfaceAddrs interfaceAddrser
}
type AutoPath struct {
Enabled bool
NDots int
ResolvConfFile string
HostSearchPath []string
OnNXDOMAIN int
}
const (
// PodModeDisabled is the default value where pod requests are ignored
PodModeDisabled = "disabled"
@ -97,6 +106,7 @@ var errInvalidRequest = errors.New("invalid query name")
var errZoneNotFound = errors.New("zone not found")
var errAPIBadPodType = errors.New("expected type *api.Pod")
var errPodsDisabled = errors.New("pod records disabled")
var errResolvConfReadErr = errors.New("resolv.conf read error")
// Services implements the ServiceBackend interface.
func (k *Kubernetes) Services(state request.Request, exact bool, opt middleware.Options) (svcs []msg.Service, debug []msg.Service, err error) {
@ -183,7 +193,7 @@ func (k *Kubernetes) Lookup(state request.Request, name string, typ uint16) (*dn
// IsNameError implements the ServiceBackend interface.
func (k *Kubernetes) IsNameError(err error) bool {
return err == errNoItems || err == errNsNotExposed || err == errInvalidRequest
return err == errNoItems || err == errNsNotExposed || err == errInvalidRequest || err == errZoneNotFound
}
// Debug implements the ServiceBackend interface.
@ -245,7 +255,7 @@ func (k *Kubernetes) InitKubeCache() (err error) {
}
opts := dnsControlOpts{
initPodCache: k.PodMode == PodModeVerified,
initPodCache: (k.PodMode == PodModeVerified || k.AutoPath.Enabled),
}
k.APIConn = newdnsController(kubeClient, k.ResyncPeriod, k.Selector, opts)
@ -448,6 +458,21 @@ func ipFromPodName(podname string) string {
return strings.Replace(podname, "-", ":", -1)
}
func (k *Kubernetes) findPodWithIP(ip string) (p *api.Pod) {
if k.PodMode != PodModeVerified {
return nil
}
objList := k.APIConn.PodIndex(ip)
for _, o := range objList {
p, ok := o.(*api.Pod)
if !ok {
return nil
}
return p
}
return nil
}
func (k *Kubernetes) findPods(namespace, podname string) (pods []pod, err error) {
if k.PodMode == PodModeDisabled {
return pods, errPodsDisabled
@ -634,3 +659,11 @@ func (k *Kubernetes) localPodIP() net.IP {
}
return nil
}
func splitSearch(zone, question, namespace string) (name, search string, ok bool) {
search = strings.Join([]string{namespace, "svc", zone}, ".")
if dns.IsSubDomain(search, question) {
return question[:len(question)-len(search)-1], search, true
}
return "", "", false
}