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|
package setup
import (
"errors"
"fmt"
"log"
"strings"
"time"
"github.com/miekg/coredns/middleware"
"github.com/miekg/coredns/middleware/kubernetes"
"github.com/miekg/coredns/middleware/kubernetes/nametemplate"
unversionedapi "k8s.io/kubernetes/pkg/api/unversioned"
)
const (
defaultNameTemplate = "{service}.{namespace}.{zone}"
defaultResyncPeriod = 5 * time.Minute
)
// Kubernetes sets up the kubernetes middleware.
func Kubernetes(c *Controller) (middleware.Middleware, error) {
kubernetes, err := kubernetesParse(c)
if err != nil {
return nil, err
}
err = kubernetes.StartKubeCache()
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) {
var err error
template := defaultNameTemplate
k8s := kubernetes.Kubernetes{
ResyncPeriod: defaultResyncPeriod,
}
k8s.NameTemplate = new(nametemplate.NameTemplate)
k8s.NameTemplate.SetTemplate(template)
// TODO: expose resync period in Corefile
for c.Next() {
if c.Val() == "kubernetes" {
zones := c.RemainingArgs()
if len(zones) == 0 {
k8s.Zones = c.ServerBlockHosts
log.Printf("[debug] Zones(from ServerBlockHosts): %v", zones)
} else {
// Normalize requested zones
k8s.Zones = kubernetes.NormalizeZoneList(zones)
}
middleware.Zones(k8s.Zones).FullyQualify()
if k8s.Zones == nil || len(k8s.Zones) < 1 {
err = errors.New("Zone name must be provided for kubernetes middleware.")
log.Printf("[debug] %v\n", err)
return kubernetes.Kubernetes{}, err
}
for c.NextBlock() {
switch c.Val() {
case "template":
args := c.RemainingArgs()
if len(args) != 0 {
template := strings.Join(args, "")
err = k8s.NameTemplate.SetTemplate(template)
if err != nil {
return kubernetes.Kubernetes{}, err
}
} else {
log.Printf("[debug] 'template' keyword provided without any template value.")
return kubernetes.Kubernetes{}, c.ArgErr()
}
case "namespaces":
args := c.RemainingArgs()
if len(args) != 0 {
k8s.Namespaces = append(k8s.Namespaces, args...)
} else {
log.Printf("[debug] 'namespaces' keyword provided without any namespace values.")
return kubernetes.Kubernetes{}, c.ArgErr()
}
case "endpoint":
args := c.RemainingArgs()
if len(args) != 0 {
k8s.APIEndpoint = args[0]
} else {
log.Printf("[debug] 'endpoint' keyword provided without any endpoint url value.")
return kubernetes.Kubernetes{}, c.ArgErr()
}
case "resyncperiod":
args := c.RemainingArgs()
if len(args) != 0 {
k8s.ResyncPeriod, err = time.ParseDuration(args[0])
if err != nil {
err = errors.New(fmt.Sprintf("Unable to parse resync duration value. Value provided was '%v'. Example valid values: '15s', '5m', '1h'. Error was: %v", args[0], err))
log.Printf("[ERROR] %v", err)
return kubernetes.Kubernetes{}, err
}
} else {
log.Printf("[debug] 'resyncperiod' keyword provided without any duration value.")
return kubernetes.Kubernetes{}, c.ArgErr()
}
case "labels":
args := c.RemainingArgs()
if len(args) != 0 {
labelSelectorString := strings.Join(args, " ")
k8s.LabelSelector, err = unversionedapi.ParseToLabelSelector(labelSelectorString)
if err != nil {
err = errors.New(fmt.Sprintf("Unable to parse label selector. Value provided was '%v'. Error was: %v", labelSelectorString, err))
log.Printf("[ERROR] %v", err)
return kubernetes.Kubernetes{}, err
}
} else {
log.Printf("[debug] 'labels' keyword provided without any selector value.")
return kubernetes.Kubernetes{}, c.ArgErr()
}
}
}
return k8s, nil
}
}
err = errors.New("Kubernetes setup called without keyword 'kubernetes' in Corefile")
log.Printf("[ERROR] %v\n", err)
return kubernetes.Kubernetes{}, err
}
|
