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|
package kubernetes
import (
"errors"
"fmt"
"strconv"
"strings"
"time"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/pkg/parse"
"github.com/coredns/coredns/plugin/pkg/upstream"
"github.com/mholt/caddy"
"github.com/miekg/dns"
meta "k8s.io/apimachinery/pkg/apis/meta/v1"
)
func init() {
caddy.RegisterPlugin("kubernetes", caddy.Plugin{
ServerType: "dns",
Action: setup,
})
}
func setup(c *caddy.Controller) error {
k, err := kubernetesParse(c)
if err != nil {
return plugin.Error("kubernetes", err)
}
err = k.InitKubeCache()
if err != nil {
return plugin.Error("kubernetes", err)
}
k.RegisterKubeCache(c)
dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
k.Next = next
return k
})
return nil
}
// RegisterKubeCache registers KubeCache start and stop functions with Caddy
func (k *Kubernetes) RegisterKubeCache(c *caddy.Controller) {
c.OnStartup(func() error {
go k.APIConn.Run()
if k.APIProxy != nil {
k.APIProxy.Run()
}
synced := false
for synced == false {
synced = k.APIConn.HasSynced()
time.Sleep(100 * time.Millisecond)
}
return nil
})
c.OnShutdown(func() error {
if k.APIProxy != nil {
k.APIProxy.Stop()
}
return k.APIConn.Stop()
})
}
func kubernetesParse(c *caddy.Controller) (*Kubernetes, error) {
var k8s *Kubernetes
var err error
for i := 1; c.Next(); i++ {
if i > 1 {
return nil, fmt.Errorf("only one kubernetes section allowed per server block")
}
k8s, err = ParseStanza(c)
if err != nil {
return k8s, err
}
}
return k8s, nil
}
// ParseStanza parses a kubernetes stanza
func ParseStanza(c *caddy.Controller) (*Kubernetes, error) {
k8s := New([]string{""})
k8s.interfaceAddrsFunc = localPodIP
k8s.autoPathSearch = searchFromResolvConf()
opts := dnsControlOpts{
resyncPeriod: defaultResyncPeriod,
}
k8s.opts = opts
zones := c.RemainingArgs()
if len(zones) != 0 {
k8s.Zones = zones
for i := 0; i < len(k8s.Zones); i++ {
k8s.Zones[i] = plugin.Host(k8s.Zones[i]).Normalize()
}
} else {
k8s.Zones = make([]string, len(c.ServerBlockKeys))
for i := 0; i < len(c.ServerBlockKeys); i++ {
k8s.Zones[i] = plugin.Host(c.ServerBlockKeys[i]).Normalize()
}
}
k8s.primaryZoneIndex = -1
for i, z := range k8s.Zones {
if strings.HasSuffix(z, "in-addr.arpa.") || strings.HasSuffix(z, "ip6.arpa.") {
continue
}
k8s.primaryZoneIndex = i
break
}
if k8s.primaryZoneIndex == -1 {
return nil, errors.New("non-reverse zone name must be used")
}
for c.NextBlock() {
switch c.Val() {
case "endpoint_pod_names":
args := c.RemainingArgs()
if len(args) > 0 {
return nil, c.ArgErr()
}
k8s.endpointNameMode = true
continue
case "pods":
args := c.RemainingArgs()
if len(args) == 1 {
switch args[0] {
case podModeDisabled, podModeInsecure, podModeVerified:
k8s.podMode = args[0]
default:
return nil, fmt.Errorf("wrong value for pods: %s, must be one of: disabled, verified, insecure", args[0])
}
continue
}
return nil, c.ArgErr()
case "namespaces":
args := c.RemainingArgs()
if len(args) > 0 {
for _, a := range args {
k8s.Namespaces[a] = true
}
continue
}
return nil, c.ArgErr()
case "endpoint":
args := c.RemainingArgs()
if len(args) > 0 {
k8s.APIServerList = args
continue
}
return nil, c.ArgErr()
case "tls": // cert key cacertfile
args := c.RemainingArgs()
if len(args) == 3 {
k8s.APIClientCert, k8s.APIClientKey, k8s.APICertAuth = args[0], args[1], args[2]
continue
}
return nil, c.ArgErr()
case "resyncperiod":
args := c.RemainingArgs()
if len(args) > 0 {
rp, err := time.ParseDuration(args[0])
if err != nil {
return nil, fmt.Errorf("unable to parse resync duration value: '%v': %v", args[0], err)
}
k8s.opts.resyncPeriod = rp
continue
}
return nil, c.ArgErr()
case "labels":
args := c.RemainingArgs()
if len(args) > 0 {
labelSelectorString := strings.Join(args, " ")
ls, err := meta.ParseToLabelSelector(labelSelectorString)
if err != nil {
return nil, fmt.Errorf("unable to parse label selector value: '%v': %v", labelSelectorString, err)
}
k8s.opts.labelSelector = ls
continue
}
return nil, c.ArgErr()
case "fallthrough":
k8s.Fall.SetZonesFromArgs(c.RemainingArgs())
case "upstream":
args := c.RemainingArgs()
u, err := upstream.NewUpstream(args)
if err != nil {
return nil, err
}
k8s.Upstream = u
case "ttl":
args := c.RemainingArgs()
if len(args) == 0 {
return nil, c.ArgErr()
}
t, err := strconv.Atoi(args[0])
if err != nil {
return nil, err
}
if t < 5 || t > 3600 {
return nil, c.Errf("ttl must be in range [5, 3600]: %d", t)
}
k8s.ttl = uint32(t)
case "transfer":
tos, froms, err := parse.Transfer(c, false)
if err != nil {
return nil, err
}
if len(froms) != 0 {
return nil, c.Errf("transfer from is not supported with this plugin")
}
k8s.TransferTo = tos
default:
return nil, c.Errf("unknown property '%s'", c.Val())
}
}
return k8s, nil
}
func searchFromResolvConf() []string {
rc, err := dns.ClientConfigFromFile("/etc/resolv.conf")
if err != nil {
return nil
}
plugin.Zones(rc.Search).Normalize()
return rc.Search
}
const defaultResyncPeriod = 5 * time.Minute
|
