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coredns/core/setup/kubernetes.go

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BK8s datasource middleware -- PoC for A records (#153) * Laying down kubernetes middleware foundation * Duplicated a bunch of code form etcd middleware * Duplicated code hacked to compile and load as a separate middleware * Adding verbose build option to Makefile * Removing stubzone and tls support tls and stubzone support was carried over from base etcd middleware code. Removing to simplify the kube middleware implementation. (For now.) * Adding conf directory for sample conf files * Removing stubzone support from query handler * Remove upstream and proxy from k8s corefile. Not sure that upstream or proxy makes sense for a k8s backed zone. * Comment out use of singleflight serialization * Removing parsing support for "upstream" directive from k8s * Removing upstream directive parsing code * Removing CNAME and TXT lookup implementation * Create README.md Brain-dump of DNS record name assembly and open work items. * Adding notes about wildcard handling * Adding basic k8s API client * Fleshing out methods on k8s connector * Remove PathPrefix from middleware init * Removing incorrect plural * Adding brute-force k8s service lookup functions * Initializing k8s API connector during startup * Hacking around to call k8s connector * Parsing incoming domain name into serviceName and namespace * Improving and simplifying k8s zone matching and label segmentation * Removing unused functions carried over from etcd middleware * Adding basic return of k8s data to DNS client * updated debugging println statements to flag with "[debug]" * removed code in kubernetes.go::Records that was a hold-over from etcd middleware. * Removed some random exploratory hacking. * Minior README.md updates * Updating with demo instructions * Updating README.md with CoreFile and removing completed TODO items * Updating conf file and README to reflect DNS response cache works * Disabling DNS response caching * Adding debug statement on entry to Records() * Changing port number in exampes to port 53. * Misc style and clarity changes * Removing empty function definitions * Adding comment to track future cleanup * Refactoring README to follow style of other middleware * Exposing dataobject field (typo)
2016-06-06 12:49:53 -07:00
package setup
import (
// "crypto/tls"
// "crypto/x509"
"fmt"
// "io/ioutil"
// "net"
// "net/http"
// "time"
"github.com/miekg/coredns/middleware"
"github.com/miekg/coredns/middleware/kubernetes"
k8sc "github.com/miekg/coredns/middleware/kubernetes/k8sclient"
"github.com/miekg/coredns/middleware/proxy"
// "github.com/miekg/coredns/middleware/singleflight"
"golang.org/x/net/context"
)
const defaultK8sEndpoint = "http://localhost:8080"
// Kubernetes sets up the kubernetes middleware.
func Kubernetes(c *Controller) (middleware.Middleware, error) {
fmt.Println("controller %v", c)
// TODO: Determine if subzone support required
kubernetes, err := kubernetesParse(c)
if err != nil {
return nil, err
}
return func(next middleware.Handler) middleware.Handler {
kubernetes.Next = next
return kubernetes
}, nil
}
func kubernetesParse(c *Controller) (kubernetes.Kubernetes, error) {
/*
* TODO: Remove unused state and simplify.
* Inflight and Ctx might not be needed. Leaving in place until
* we take a pass at API caching and optimizing connector to the
* k8s API. Single flight (or limited upper-bound) for inflight
* API calls may be desirable.
*/
k8s := kubernetes.Kubernetes{
Proxy: proxy.New([]string{}),
Ctx: context.Background(),
// Inflight: &singleflight.Group{},
APIConn: nil,
}
var (
endpoints = []string{defaultK8sEndpoint}
)
for c.Next() {
if c.Val() == "kubernetes" {
k8s.Zones = c.RemainingArgs()
if len(k8s.Zones) == 0 {
k8s.Zones = c.ServerBlockHosts
}
middleware.Zones(k8s.Zones).FullyQualify()
if c.NextBlock() {
// TODO(miek): 2 switches?
switch c.Val() {
case "endpoint":
args := c.RemainingArgs()
if len(args) == 0 {
return kubernetes.Kubernetes{}, c.ArgErr()
}
endpoints = args
k8s.APIConn = k8sc.NewK8sConnector(endpoints[0])
}
for c.Next() {
switch c.Val() {
case "endpoint":
args := c.RemainingArgs()
if len(args) == 0 {
return kubernetes.Kubernetes{}, c.ArgErr()
}
endpoints = args
}
}
}
return k8s, nil
}
fmt.Println("endpoints='%v'", endpoints)
}
return kubernetes.Kubernetes{}, nil
}