diff options
Diffstat (limited to 'middleware/kubernetes/kubernetes.go')
| -rw-r--r-- | middleware/kubernetes/kubernetes.go | 171 |
1 files changed, 40 insertions, 131 deletions
diff --git a/middleware/kubernetes/kubernetes.go b/middleware/kubernetes/kubernetes.go index 1b07d30d5..417436904 100644 --- a/middleware/kubernetes/kubernetes.go +++ b/middleware/kubernetes/kubernetes.go @@ -11,6 +11,7 @@ import ( "github.com/coredns/coredns/middleware" "github.com/coredns/coredns/middleware/etcd/msg" + "github.com/coredns/coredns/middleware/pkg/dnsutil" dnsstrings "github.com/coredns/coredns/middleware/pkg/strings" "github.com/coredns/coredns/middleware/proxy" "github.com/coredns/coredns/request" @@ -64,7 +65,8 @@ type endpoint struct { port api.EndpointPort } -type service struct { +// kService is a service as retrieved via the k8s API. +type kService struct { name string namespace string addr string @@ -72,23 +74,13 @@ type service struct { endpoints []endpoint } -type pod struct { +// kPod is a pod as retrieved via the k8s API. +type kPod struct { name string namespace string addr string } -type recordRequest struct { - port string - protocol string - endpoint string - service string - namespace string - typeName string - zone string - federation string -} - var ( errNoItems = errors.New("no items found") errNsNotExposed = errors.New("namespace is not exposed") @@ -100,12 +92,33 @@ var ( // Services implements the ServiceBackend interface. func (k *Kubernetes) Services(state request.Request, exact bool, opt middleware.Options) (svcs []msg.Service, debug []msg.Service, err error) { - r, e := k.parseRequest(state.Name(), state.QType()) + + // We're looking again at types, which we've already done in ServeDNS, but there are some types k8s just can't answer. + switch state.QType() { + case dns.TypeTXT: + // 1 label + zone, label must be "dns-version" + t, err := dnsutil.TrimZone(state.Name(), state.Zone) + if err != nil { + return nil, nil, err + } + segs := dns.SplitDomainName(t) + if len(segs) != 1 { + return nil, nil, errors.New("servfail") + } + if segs[0] != "dns-version" { + return nil, nil, errInvalidRequest + } + svc := msg.Service{Text: DNSSchemaVersion, TTL: 28800, Key: msg.Path(state.QName(), "coredns")} + return []msg.Service{svc}, nil, nil + } + + r, e := k.parseRequest(state.Name(), state.QType(), state.Zone) if e != nil { return nil, nil, e } - switch state.Type() { - case "A", "AAAA", "CNAME": + + switch state.QType() { + case dns.TypeA, dns.TypeAAAA, dns.TypeCNAME: if state.Type() == "A" && isDefaultNS(state.Name(), r) { // If this is an A request for "ns.dns", respond with a "fake" record for coredns. // SOA records always use this hardcoded name @@ -118,7 +131,7 @@ func (k *Kubernetes) Services(state request.Request, exact bool, opt middleware. return nil, nil, e } return s, nil, e // Haven't implemented debug queries yet. - case "SRV": + case dns.TypeSRV: s, e := k.Entries(r) // SRV for external services is not yet implemented, so remove those records noext := []msg.Service{} @@ -128,13 +141,7 @@ func (k *Kubernetes) Services(state request.Request, exact bool, opt middleware. } } return noext, nil, e - case "TXT": - if r.typeName == "dns-version" { - srv := k.recordsForTXT(r) - svcs = append(svcs, srv) - } - return svcs, nil, err - case "NS": + case dns.TypeNS: srv := k.recordsForNS(r) svcs = append(svcs, srv) return svcs, nil, err @@ -142,11 +149,6 @@ func (k *Kubernetes) Services(state request.Request, exact bool, opt middleware. return nil, nil, nil } -func (k *Kubernetes) recordsForTXT(r recordRequest) msg.Service { - return msg.Service{Text: DNSSchemaVersion, TTL: 28800, - Key: msg.Path(strings.Join([]string{r.typeName, r.zone}, "."), "coredns")} -} - func (k *Kubernetes) recordsForNS(r recordRequest) msg.Service { ns := k.coreDNSRecord() return msg.Service{Host: ns.A.String(), @@ -234,99 +236,6 @@ func (k *Kubernetes) InitKubeCache() (err error) { return err } -func (k *Kubernetes) parseRequest(lowerCasedName string, qtype uint16) (r recordRequest, err error) { - // 3 Possible cases - // SRV Request: _port._protocol.service.namespace.[federation.]type.zone - // A Request (endpoint): endpoint.service.namespace.[federation.]type.zone - // A Request (service): service.namespace.[federation.]type.zone - - // separate zone from rest of lowerCasedName - var segs []string - for _, z := range k.Zones { - if dns.IsSubDomain(z, lowerCasedName) { - r.zone = z - - segs = dns.SplitDomainName(lowerCasedName) - segs = segs[:len(segs)-dns.CountLabel(r.zone)] - break - } - } - if r.zone == "" { - return r, errZoneNotFound - } - - r.federation, segs = k.stripFederation(segs) - - if qtype == dns.TypeNS { - return r, nil - } - - if qtype == dns.TypeA && isDefaultNS(lowerCasedName, r) { - return r, nil - } - - offset := 0 - if qtype == dns.TypeSRV { - // The kubernetes peer-finder expects queries with empty port and service to resolve - // If neither is specified, treat it as a wildcard - if len(segs) == 3 { - r.port = "*" - r.service = "*" - offset = 0 - } else { - if len(segs) != 5 { - return r, errInvalidRequest - } - // This is a SRV style request, get first two elements as port and - // protocol, stripping leading underscores if present. - if segs[0][0] == '_' { - r.port = segs[0][1:] - } else { - r.port = segs[0] - if !wildcard(r.port) { - return r, errInvalidRequest - } - } - if segs[1][0] == '_' { - r.protocol = segs[1][1:] - if r.protocol != "tcp" && r.protocol != "udp" { - return r, errInvalidRequest - } - } else { - r.protocol = segs[1] - if !wildcard(r.protocol) { - return r, errInvalidRequest - } - } - if r.port == "" || r.protocol == "" { - return r, errInvalidRequest - } - offset = 2 - } - } - if (qtype == dns.TypeA || qtype == dns.TypeAAAA) && len(segs) == 4 { - // This is an endpoint A/AAAA record request. Get first element as endpoint. - r.endpoint = segs[0] - offset = 1 - } - - if len(segs) == (offset + 3) { - r.service = segs[offset] - r.namespace = segs[offset+1] - r.typeName = segs[offset+2] - - return r, nil - } - - if len(segs) == 1 && qtype == dns.TypeTXT { - r.typeName = segs[0] - return r, nil - } - - return r, errInvalidRequest - -} - // Records not implemented, see Entries(). func (k *Kubernetes) Records(name string, exact bool) ([]msg.Service, error) { return nil, fmt.Errorf("NOOP") @@ -375,7 +284,7 @@ func endpointHostname(addr api.EndpointAddress) string { return "" } -func (k *Kubernetes) getRecordsForK8sItems(services []service, pods []pod, r recordRequest) (records []msg.Service) { +func (k *Kubernetes) getRecordsForK8sItems(services []kService, pods []kPod, r recordRequest) (records []msg.Service) { zonePath := msg.Path(r.zone, "coredns") for _, svc := range services { @@ -435,7 +344,7 @@ func (k *Kubernetes) getRecordsForK8sItems(services []service, pods []pod, r rec return records } -func (k *Kubernetes) findPods(namespace, podname string) (pods []pod, err error) { +func (k *Kubernetes) findPods(namespace, podname string) (pods []kPod, err error) { if k.PodMode == PodModeDisabled { return pods, errPodsDisabled } @@ -448,7 +357,7 @@ func (k *Kubernetes) findPods(namespace, podname string) (pods []pod, err error) } if k.PodMode == PodModeInsecure { - s := pod{name: podname, namespace: namespace, addr: ip} + s := kPod{name: podname, namespace: namespace, addr: ip} pods = append(pods, s) return pods, nil } @@ -468,7 +377,7 @@ func (k *Kubernetes) findPods(namespace, podname string) (pods []pod, err error) } // check for matching ip and namespace if ip == p.Status.PodIP && match(namespace, p.Namespace, nsWildcard) { - s := pod{name: podname, namespace: namespace, addr: ip} + s := kPod{name: podname, namespace: namespace, addr: ip} pods = append(pods, s) return pods, nil } @@ -477,9 +386,9 @@ func (k *Kubernetes) findPods(namespace, podname string) (pods []pod, err error) } // get retrieves matching data from the cache. -func (k *Kubernetes) get(r recordRequest) (services []service, pods []pod, err error) { +func (k *Kubernetes) get(r recordRequest) (services []kService, pods []kPod, err error) { switch { - case r.typeName == Pod: + case r.podOrSvc == Pod: pods, err = k.findPods(r.namespace, r.service) return nil, pods, err default: @@ -488,9 +397,9 @@ func (k *Kubernetes) get(r recordRequest) (services []service, pods []pod, err e } } -func (k *Kubernetes) findServices(r recordRequest) ([]service, error) { +func (k *Kubernetes) findServices(r recordRequest) ([]kService, error) { serviceList := k.APIConn.ServiceList() - var resultItems []service + var resultItems []kService nsWildcard := wildcard(r.namespace) serviceWildcard := wildcard(r.service) @@ -506,7 +415,7 @@ func (k *Kubernetes) findServices(r recordRequest) ([]service, error) { if nsWildcard && (len(k.Namespaces) > 0) && (!dnsstrings.StringInSlice(svc.Namespace, k.Namespaces)) { continue } - s := service{name: svc.Name, namespace: svc.Namespace} + s := kService{name: svc.Name, namespace: svc.Namespace} // Endpoint query or headless service if svc.Spec.ClusterIP == api.ClusterIPNone || r.endpoint != "" { |