mirror of
https://github.com/coredns/coredns.git
synced 2025-10-31 10:13:14 -04:00
116 lines
2.7 KiB
Go
116 lines
2.7 KiB
Go
package kubernetes
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import (
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"net"
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"strings"
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"github.com/coredns/coredns/middleware/etcd/msg"
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"github.com/miekg/dns"
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"k8s.io/client-go/1.5/pkg/api"
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)
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const defaultNSName = "ns.dns."
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var corednsRecord dns.A
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type interfaceAddrser interface {
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interfaceAddrs() ([]net.Addr, error)
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}
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type interfaceAddrs struct{}
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func (i interfaceAddrs) interfaceAddrs() ([]net.Addr, error) {
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return net.InterfaceAddrs()
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}
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func (k *Kubernetes) recordsForNS(r recordRequest, svcs *[]msg.Service) error {
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ns := k.coreDNSRecord()
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s := msg.Service{
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Host: ns.A.String(),
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Key: msg.Path(strings.Join([]string{ns.Hdr.Name, r.zone}, "."), "coredns")}
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*svcs = append(*svcs, s)
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return nil
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}
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// DefaultNSMsg returns an msg.Service representing an A record for
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// ns.dns.[zone] -> dns service ip. This A record is needed to legitimize
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// the SOA response in middleware.NS(), which is hardcoded at ns.dns.[zone].
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func (k *Kubernetes) defaultNSMsg(r recordRequest) msg.Service {
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ns := k.coreDNSRecord()
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s := msg.Service{
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Key: msg.Path(strings.Join([]string{defaultNSName, r.zone}, "."), "coredns"),
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Host: ns.A.String(),
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}
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return s
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}
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func isDefaultNS(name string, r recordRequest) bool {
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return strings.Index(name, defaultNSName) == 0 && strings.Index(name, r.zone) == len(defaultNSName)
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}
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func (k *Kubernetes) coreDNSRecord() dns.A {
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var localIP net.IP
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var svcName string
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var svcNamespace string
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var dnsIP net.IP
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if len(corednsRecord.Hdr.Name) == 0 || corednsRecord.A == nil {
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// get local Pod IP
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addrs, _ := k.interfaceAddrs.interfaceAddrs()
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for _, addr := range addrs {
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ip, _, _ := net.ParseCIDR(addr.String())
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ip = ip.To4()
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if ip == nil || ip.IsLoopback() {
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continue
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}
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localIP = ip
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break
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}
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// Find endpoint matching IP to get service and namespace
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endpointsList := k.APIConn.EndpointsList()
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FindEndpoint:
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for _, ep := range endpointsList.Items {
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for _, eps := range ep.Subsets {
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for _, addr := range eps.Addresses {
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if localIP.Equal(net.ParseIP(addr.IP)) {
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svcNamespace = ep.ObjectMeta.Namespace
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svcName = ep.ObjectMeta.Name
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break FindEndpoint
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}
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}
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}
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}
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if len(svcName) == 0 {
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corednsRecord.Hdr.Name = defaultNSName
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corednsRecord.A = localIP
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return corednsRecord
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}
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// Find service to get ClusterIP
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serviceList := k.APIConn.ServiceList()
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FindService:
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for _, svc := range serviceList {
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if svcName == svc.Name && svcNamespace == svc.Namespace {
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if svc.Spec.ClusterIP == api.ClusterIPNone {
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dnsIP = localIP
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} else {
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dnsIP = net.ParseIP(svc.Spec.ClusterIP)
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}
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break FindService
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}
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}
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if dnsIP == nil {
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dnsIP = localIP
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}
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corednsRecord.Hdr.Name = strings.Join([]string{svcName, svcNamespace, "svc."}, ".")
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corednsRecord.A = dnsIP
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}
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return corednsRecord
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}
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