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|
package kubernetes
import (
"errors"
"fmt"
"strings"
"time"
"github.com/miekg/coredns/core/dnsserver"
"github.com/miekg/coredns/middleware"
"github.com/miekg/coredns/middleware/kubernetes/nametemplate"
"github.com/mholt/caddy"
unversionedapi "k8s.io/kubernetes/pkg/api/unversioned"
)
func init() {
caddy.RegisterPlugin("kubernetes", caddy.Plugin{
ServerType: "dns",
Action: setup,
})
}
func setup(c *caddy.Controller) error {
kubernetes, err := kubernetesParse(c)
if err != nil {
return err
}
err = kubernetes.InitKubeCache()
if err != nil {
return err
}
// Register KubeCache start and stop functions with Caddy
c.OnStartup(func() error {
go kubernetes.APIConn.Run()
return nil
})
c.OnShutdown(func() error {
return kubernetes.APIConn.Stop()
})
dnsserver.GetConfig(c).AddMiddleware(func(next dnsserver.Handler) dnsserver.Handler {
kubernetes.Next = next
return kubernetes
})
return nil
}
func kubernetesParse(c *caddy.Controller) (Kubernetes, error) {
var err error
template := defaultNameTemplate
k8s := Kubernetes{ResyncPeriod: defaultResyncPeriod}
k8s.NameTemplate = new(nametemplate.NameTemplate)
k8s.NameTemplate.SetTemplate(template)
for c.Next() {
if c.Val() == "kubernetes" {
zones := c.RemainingArgs()
if len(zones) == 0 {
k8s.Zones = make([]string, len(c.ServerBlockKeys))
copy(k8s.Zones, c.ServerBlockKeys)
}
k8s.Zones = 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.")
return 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{}, err
}
} else {
return Kubernetes{}, c.ArgErr()
}
case "namespaces":
args := c.RemainingArgs()
if len(args) != 0 {
k8s.Namespaces = append(k8s.Namespaces, args...)
} else {
return Kubernetes{}, c.ArgErr()
}
case "endpoint":
args := c.RemainingArgs()
if len(args) != 0 {
k8s.APIEndpoint = args[0]
} else {
return 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))
return Kubernetes{}, err
}
} else {
return 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))
return Kubernetes{}, err
}
} else {
return Kubernetes{}, c.ArgErr()
}
}
}
return k8s, nil
}
}
err = errors.New("Kubernetes setup called without keyword 'kubernetes' in Corefile")
return Kubernetes{}, err
}
const (
defaultNameTemplate = "{service}.{namespace}.{zone}"
defaultResyncPeriod = 5 * time.Minute
)
|
