func (s *server) PTRRecords(q dns.Question) (records []dns.RR, err error) { name := strings.ToLower(q.Name) path, star := msg.PathWithWildcard(name) if star { return nil, fmt.Errorf("reverse can not contain wildcards") } r, err := get(s.client, path, false) if err != nil { // if server has a forward, forward the query return nil, err } if r.Node.Dir { return nil, fmt.Errorf("reverse should not be a directory") } serv := new(msg.Service) if err := json.Unmarshal([]byte(r.Node.Value), serv); err != nil { s.config.log.Infof("failed to parse json: %s", err.Error()) return nil, err } ttl := uint32(r.Node.TTL) if ttl == 0 { ttl = s.config.Ttl } serv.Key = r.Node.Key // If serv.Host is parseble as a IP address we should not return anything. // TODO(miek). records = append(records, serv.NewPTR(q.Name, ttl)) return records, nil }
func (g *Backend) Records(name string, exact bool) ([]msg.Service, error) { path, star := msg.PathWithWildcard(name) bits := strings.Split(path, "/") fmt.Println(bits, path, star) srv := msg.Service{} srv.Host = "192.168.5.1" l := make([]msg.Service, 0) l = append(l, srv) return l, nil // errors.New("FAIL") }
// Handle API add service requests func (s *Server) addServiceHTTPHandler(w http.ResponseWriter, req *http.Request) { addServiceCount.Inc(1) vars := mux.Vars(req) var uuid string var ok bool var secret string //read the authorization header to get the secret. secret = req.Header.Get("Authorization") if err := s.authenticate(secret); err != nil { http.Error(w, err.Error(), http.StatusForbidden) return } if uuid, ok = vars["uuid"]; !ok { http.Error(w, "UUID required", http.StatusBadRequest) return } var serv msg.Service if err := json.NewDecoder(req.Body).Decode(&serv); err != nil { log.Println("Error: ", err) http.Error(w, err.Error(), http.StatusInternalServerError) return } if serv.Host == "" || serv.Port == 0 { http.Error(w, "Host and Port required", http.StatusBadRequest) return } serv.UUID = uuid if _, err := s.raftServer.Do(NewAddServiceCommand(serv)); err != nil { switch err { case registry.ErrExists: http.Error(w, err.Error(), http.StatusConflict) case raft.NotLeaderError: s.redirectToLeader(w, req) default: log.Println("Error: ", err) http.Error(w, err.Error(), http.StatusInternalServerError) } return } w.WriteHeader(http.StatusCreated) }
func (g *Backend) decode(n *etcd.Node) (*msg.Service, error) { serv := new(msg.Service) if err := json.Unmarshal([]byte(n.Value), serv); err != nil { return nil, err } serv.Key = n.Key serv.Ttl = g.calculateTtl(n, serv) if serv.Priority == 0 { serv.Priority = int(g.config.Priority) } return serv, nil }
// loopNodes recursively loops through the nodes and returns all the values. The nodes' keyname // will be match against any wildcards when star is true. func (g *Backend) loopNodes(ns []*etcd.Node, nameParts []string, star bool, bx map[bareService]bool) (sx []msg.Service, err error) { if bx == nil { bx = make(map[bareService]bool) } Nodes: for _, n := range ns { if n.Dir { nodes, err := g.loopNodes(n.Nodes, nameParts, star, bx) if err != nil { return nil, err } sx = append(sx, nodes...) continue } if star { keyParts := strings.Split(n.Key, "/") for i, n := range nameParts { if i > len(keyParts)-1 { // name is longer than key continue Nodes } if n == "*" || n == "any" { continue } if keyParts[i] != n { continue Nodes } } } serv := new(msg.Service) if err := json.Unmarshal([]byte(n.Value), serv); err != nil { return nil, err } b := bareService{serv.Host, serv.Port, serv.Priority, serv.Weight, serv.Text} if _, ok := bx[b]; ok { continue } bx[b] = true serv.Key = n.Key serv.Ttl = g.calculateTtl(n, serv) if serv.Priority == 0 { serv.Priority = int(g.config.Priority) } sx = append(sx, *serv) } return sx, nil }
func (g *Backendv3) loopNodes(kv []*mvccpb.KeyValue, nameParts []string, star bool, bx map[bareService]bool) (sx []msg.Service, err error) { if bx == nil { bx = make(map[bareService]bool) } Nodes: for _, item := range kv { if star { s := string(item.Key[:]) keyParts := strings.Split(s, "/") for i, n := range nameParts { if i > len(keyParts)-1 { continue Nodes } if n == "*" || n == "any" { continue } if keyParts[i] != n { continue Nodes } } } serv := new(msg.Service) if err := json.Unmarshal(item.Value, serv); err != nil { return nil, err } b := bareService{serv.Host, serv.Port, serv.Priority, serv.Weight, serv.Text} bx[b] = true serv.Key = string(item.Key) //TODO: another call (LeaseRequest) for TTL when RPC in etcdv3 is ready serv.Ttl = g.calculateTtl(item, serv) if serv.Priority == 0 { serv.Priority = int(g.config.Priority) } sx = append(sx, *serv) } return sx, nil }
func writeService(c *cli.Context, service *msg.Service) { if c.GlobalBool("json") { if err := json.NewEncoder(os.Stdout).Encode(service); err != nil { writeError(err) } } else { fmt.Printf("UUID: %s\nName: %s\nHost: %s\nPort: %d\nEnvironment: %s\nRegion: %s\nVersion: %s\n\n", service.UUID, service.Name, service.Host, service.Port, service.Environment, service.Region, service.Version) fmt.Printf("TTL %d\nRemaining TTL: %d\n", service.TTL, service.RemainingTTL()) } }
func TestGetService(t *testing.T) { s := newTestServer("", 9570, 9571, "") defer s.Stop() m := msg.Service{ UUID: "123", Name: "TestService", Version: "1.0.0", Region: "Test", Host: "localhost", Environment: "Production", Port: 9000, TTL: 4, Expires: getExpirationTime(4), } s.registry.Add(m) req, _ := http.NewRequest("GET", "/skydns/services/"+m.UUID, nil) resp := httptest.NewRecorder() s.router.ServeHTTP(resp, req) if resp.Code != http.StatusOK { t.Fatal("Failed to retrieve service") } m.TTL = 3 // TTL will be lower as time has passed expected, err := json.Marshal(m) if err != nil { t.Fatal(err) } // Newline is expected expected = append(expected, []byte("\n")...) if !bytes.Equal(resp.Body.Bytes(), expected) { t.Fatalf("Returned service is invalid. Expected %q but received %q", string(expected), resp.Body.String()) } }
func (s *server) CNAMERecords(q dns.Question, name string) (records []dns.RR, err error) { path, _ := msg.PathWithWildcard(name) // no wildcards here r, err := get(s.client, path, true) if err != nil { return nil, err } if !r.Node.Dir { serv := new(msg.Service) if err := json.Unmarshal([]byte(r.Node.Value), serv); err != nil { s.config.log.Infof("failed to parse json: %s", err.Error()) return nil, err } ip := net.ParseIP(serv.Host) ttl := s.calculateTtl(r.Node, serv) serv.Key = r.Node.Key serv.Ttl = ttl if ip == nil { records = append(records, serv.NewCNAME(q.Name, dns.Fqdn(serv.Host))) } } return records, nil }
func TestUpdateTTL(t *testing.T) { s := newTestServer("", 9540, 9541, "") defer s.Stop() m := msg.Service{ UUID: "123", Name: "TestService", Version: "1.0.0", Region: "Test", Host: "localhost", Environment: "Production", Port: 9000, TTL: 4, } s.registry.Add(m) m.TTL = 25 b, err := json.Marshal(m) if err != nil { t.Fatal(err) } req, _ := http.NewRequest("PATCH", "/skydns/services/"+m.UUID, bytes.NewBuffer(b)) resp := httptest.NewRecorder() s.router.ServeHTTP(resp, req) if resp.Code != http.StatusOK { t.Fatal("Failed to update TTL") } if serv, err := s.registry.GetUUID(m.UUID); err != nil || serv.TTL != 24 { t.Fatal("Failed to update TTL", err, serv.TTL) } }
// setEntry creates the entire path if it doesn't already exist in the cache, // then sets the given service record under the given key. The path this entry // would have occupied in an etcd datastore is computed from the given fqdn and // stored as the "Key" of the skydns service; this is only required because // skydns expects the service record to contain a key in a specific format // (presumably for legacy compatibility). Note that the fqnd string typically // contains both the key and all elements in the path. func (cache *TreeCache) setEntry(key string, val *skymsg.Service, fqdn string, path ...string) { // TODO: Consolidate setEntry and setSubCache into a single method with a // type switch. // TODO: Insted of passing the fqdn as an argument, we can reconstruct // it from the path, provided callers always pass the full path to the // object. This is currently *not* the case, since callers first create // a new, empty node, populate it, then parent it under the right path. // So we don't know the full key till the final parenting operation. node := cache.ensureChildNode(path...) // This key is used to construct the "target" for SRV record lookups. // For normal service/endpoint lookups, this will result in a key like: // /skydns/local/cluster/svc/svcNS/svcName/record-hash // but for headless services that govern pods requesting a specific // hostname (as used by petset), this will end up being: // /skydns/local/cluster/svc/svcNS/svcName/pod-hostname val.Key = skymsg.Path(fqdn) node.Entries[key] = val }
// SRVRecords returns SRV records from etcd. // If the Target is not an name but an IP address, an name is created . func (s *server) SRVRecords(q dns.Question, name string, bufsize uint16, dnssec bool) (records []dns.RR, extra []dns.RR, err error) { path, star := msg.PathWithWildcard(name) r, err := get(s.client, path, true) if err != nil { return nil, nil, err } if !r.Node.Dir { // single element serv := new(msg.Service) if err := json.Unmarshal([]byte(r.Node.Value), serv); err != nil { s.config.log.Infof("failed to parse json: %s", err.Error()) return nil, nil, err } ip := net.ParseIP(serv.Host) ttl := s.calculateTtl(r.Node, serv) if serv.Priority == 0 { serv.Priority = int(s.config.Priority) } serv.Key = r.Node.Key serv.Ttl = ttl switch { case ip == nil: srv := serv.NewSRV(q.Name, uint16(100)) records = append(records, srv) if !dns.IsSubDomain(s.config.Domain, srv.Target) { m1, e1 := s.Lookup(srv.Target, dns.TypeA, bufsize, dnssec) if e1 == nil { extra = append(extra, m1.Answer...) } m1, e1 = s.Lookup(srv.Target, dns.TypeAAAA, bufsize, dnssec) if e1 == nil { // If we have seen CNAME's we *assume* that they already added. for _, a := range m1.Answer { if _, ok := a.(*dns.CNAME); !ok { extra = append(extra, a) } } } } case ip.To4() != nil: serv.Host = msg.Domain(serv.Key) records = append(records, serv.NewSRV(q.Name, uint16(100))) extra = append(extra, serv.NewA(serv.Host, ip.To4())) case ip.To4() == nil: serv.Host = msg.Domain(serv.Key) records = append(records, serv.NewSRV(q.Name, uint16(100))) extra = append(extra, serv.NewAAAA(serv.Host, ip.To16())) } return records, extra, nil } sx, err := s.loopNodes(&r.Node.Nodes, strings.Split(msg.Path(name), "/"), star, nil) if err != nil || len(sx) == 0 { return nil, nil, err } // Looping twice to get the right weight vs priority w := make(map[int]int) for _, serv := range sx { weight := 100 if serv.Weight != 0 { weight = serv.Weight } if _, ok := w[serv.Priority]; !ok { w[serv.Priority] = weight continue } w[serv.Priority] += weight } lookup := make(map[string]bool) for _, serv := range sx { w1 := 100.0 / float64(w[serv.Priority]) if serv.Weight == 0 { w1 *= 100 } else { w1 *= float64(serv.Weight) } weight := uint16(math.Floor(w1)) ip := net.ParseIP(serv.Host) switch { case ip == nil: srv := serv.NewSRV(q.Name, weight) records = append(records, srv) if _, ok := lookup[srv.Target]; !ok { if !dns.IsSubDomain(s.config.Domain, srv.Target) { m1, e1 := s.Lookup(srv.Target, dns.TypeA, bufsize, dnssec) if e1 == nil { extra = append(extra, m1.Answer...) } m1, e1 = s.Lookup(srv.Target, dns.TypeAAAA, bufsize, dnssec) if e1 == nil { // If we have seen CNAME's we *assume* that they are already added. for _, a := range m1.Answer { if _, ok := a.(*dns.CNAME); !ok { extra = append(extra, a) } } } } } lookup[srv.Target] = true case ip.To4() != nil: serv.Host = msg.Domain(serv.Key) records = append(records, serv.NewSRV(q.Name, weight)) extra = append(extra, serv.NewA(serv.Host, ip.To4())) case ip.To4() == nil: serv.Host = msg.Domain(serv.Key) records = append(records, serv.NewSRV(q.Name, weight)) extra = append(extra, serv.NewAAAA(serv.Host, ip.To16())) } } return records, extra, nil }
// Records implements the SkyDNS Backend interface and returns standard records for // a name. // // The standard pattern is <prefix>.<service_name>.<namespace>.(svc|endpoints|pod).<base> // // * prefix may be any series of prefix values // * _endpoints is a special prefix that returns the same as <service_name>.<namespace>.svc.<base> // * service_name and namespace must locate a real service // * unless a fallback is defined, in which case the fallback name will be looked up // * svc indicates standard service rules apply (clusterIP or endpoints as A records) // * reverse lookup of IP is only possible for clusterIP // * SRV records are returned for each host+port combination as: // _<port_name>._<port_protocol>.<dns> // _<port_name>.<endpoint_id>.<dns> // * endpoints always returns each individual endpoint as A records // * SRV records for endpoints are similar to SVC, but are prefixed with a single label // that is a hash of the endpoint IP // * pods is of the form <IP_with_dashes>.<namespace>.pod.<base> and resolves to <IP> // func (b *ServiceResolver) Records(dnsName string, exact bool) ([]msg.Service, error) { if !strings.HasSuffix(dnsName, b.base) { return nil, errNoSuchName } prefix := strings.Trim(strings.TrimSuffix(dnsName, b.base), ".") segments := strings.Split(prefix, ".") for i, j := 0, len(segments)-1; i < j; i, j = i+1, j-1 { segments[i], segments[j] = segments[j], segments[i] } if len(segments) == 0 { return nil, errNoSuchName } glog.V(4).Infof("Answering query %s:%t", dnsName, exact) switch base := segments[0]; base { case "pod": if len(segments) != 3 { return nil, errNoSuchName } namespace, encodedIP := segments[1], segments[2] ip := convertDashIPToIP(encodedIP) if net.ParseIP(ip) == nil { return nil, errNoSuchName } return []msg.Service{ { Host: ip, Port: 0, Priority: 10, Weight: 10, Ttl: 30, Key: msg.Path(buildDNSName(b.base, "pod", namespace, getHash(ip))), }, }, nil case "svc", "endpoints": if len(segments) < 3 { return nil, errNoSuchName } namespace, name := segments[1], segments[2] svc, err := b.accessor.Services(namespace).Get(name) if err != nil { if errors.IsNotFound(err) && b.fallback != nil { if fallback, ok := b.fallback(prefix, exact); ok { return b.Records(fallback+b.base, exact) } return nil, errNoSuchName } return nil, errNoSuchName } // no clusterIP and not headless, no DNS if len(svc.Spec.ClusterIP) == 0 && svc.Spec.Type != kapi.ServiceTypeExternalName { return nil, errNoSuchName } subdomain := buildDNSName(b.base, base, namespace, name) endpointPrefix := base == "endpoints" retrieveEndpoints := endpointPrefix || (len(segments) > 3 && segments[3] == "_endpoints") includePorts := len(segments) > 3 && hasAllPrefixedSegments(segments[3:], "_") && segments[3] != "_endpoints" // if has a portal IP and looking at svc if svc.Spec.ClusterIP != kapi.ClusterIPNone && !retrieveEndpoints { hostValue := svc.Spec.ClusterIP if svc.Spec.Type == kapi.ServiceTypeExternalName { hostValue = svc.Spec.ExternalName } defaultService := msg.Service{ Host: hostValue, Port: 0, Priority: 10, Weight: 10, Ttl: 30, } defaultHash := getHash(defaultService.Host) defaultName := buildDNSName(subdomain, defaultHash) defaultService.Key = msg.Path(defaultName) if len(svc.Spec.Ports) == 0 || !includePorts { glog.V(4).Infof("Answered %s:%t with %#v", dnsName, exact, defaultService) return []msg.Service{defaultService}, nil } services := []msg.Service{} protocolMatch, portMatch := segments[3], "*" if len(segments) > 4 { portMatch = segments[4] } for _, p := range svc.Spec.Ports { portSegment, protocolSegment, ok := matchesPortAndProtocol(p.Name, string(p.Protocol), portMatch, protocolMatch) if !ok { continue } port := p.Port if port == 0 { port = int32(p.TargetPort.IntVal) } keyName := buildDNSName(defaultName, protocolSegment, portSegment) services = append(services, msg.Service{ Host: hostValue, Port: int(port), Priority: 10, Weight: 10, Ttl: 30, TargetStrip: 2, Key: msg.Path(keyName), }, ) } if len(services) == 0 { services = append(services, defaultService) } glog.V(4).Infof("Answered %s:%t with %#v", dnsName, exact, services) return services, nil } // return endpoints endpoints, err := b.endpoints.Endpoints(namespace).Get(name) if err != nil { return nil, errNoSuchName } hostnameMappings := noHostnameMappings if savedHostnames := endpoints.Annotations[kendpoints.PodHostnamesAnnotation]; len(savedHostnames) > 0 { mapped := make(map[string]kendpoints.HostRecord) if err = json.Unmarshal([]byte(savedHostnames), &mapped); err == nil { hostnameMappings = mapped } } matchHostname := len(segments) > 3 && !hasAllPrefixedSegments(segments[3:4], "_") services := make([]msg.Service, 0, len(endpoints.Subsets)*4) for _, s := range endpoints.Subsets { for _, a := range s.Addresses { defaultService := msg.Service{ Host: a.IP, Port: 0, Priority: 10, Weight: 10, Ttl: 30, } var endpointName string if hostname, ok := getHostname(&a, hostnameMappings); ok { endpointName = hostname } else { endpointName = getHash(defaultService.Host) } if matchHostname && endpointName != segments[3] { continue } defaultName := buildDNSName(subdomain, endpointName) defaultService.Key = msg.Path(defaultName) if !includePorts { services = append(services, defaultService) continue } protocolMatch, portMatch := segments[3], "*" if len(segments) > 4 { portMatch = segments[4] } for _, p := range s.Ports { portSegment, protocolSegment, ok := matchesPortAndProtocol(p.Name, string(p.Protocol), portMatch, protocolMatch) if !ok || p.Port == 0 { continue } keyName := buildDNSName(defaultName, protocolSegment, portSegment) services = append(services, msg.Service{ Host: a.IP, Port: int(p.Port), Priority: 10, Weight: 10, Ttl: 30, TargetStrip: 2, Key: msg.Path(keyName), }) } } } glog.V(4).Infof("Answered %s:%t with %#v", dnsName, exact, services) return services, nil } return nil, errNoSuchName }
// Creates a new AddServiceCommand func NewAddServiceCommand(s msg.Service) *AddServiceCommand { s.Expires = getExpirationTime(s.TTL) return &AddServiceCommand{s} }
// Records implements the SkyDNS Backend interface and returns standard records for // a name. // // The standard pattern is <prefix>.<service_name>.<namespace>.(svc|endpoints|pod).<base> // // * prefix may be any series of prefix values // * _endpoints is a special prefix that returns the same as <service_name>.<namespace>.svc.<base> // * service_name and namespace must locate a real service // * unless a fallback is defined, in which case the fallback name will be looked up // * svc indicates standard service rules apply (portalIP or endpoints as A records) // * reverse lookup of IP is only possible for portalIP // * SRV records are returned for each host+port combination as: // _<port_name>._<port_protocol>.<dns> // _<port_name>.<endpoint_id>.<dns> // * endpoints always returns each individual endpoint as A records // * SRV records for endpoints are similar to SVC, but are prefixed with a single label // that is a hash of the endpoint IP // * pods is of the form <IP_with_dashes>.<namespace>.pod.<base> and resolves to <IP> // func (b *ServiceResolver) Records(dnsName string, exact bool) ([]msg.Service, error) { if !strings.HasSuffix(dnsName, b.base) { return nil, nil } prefix := strings.Trim(strings.TrimSuffix(dnsName, b.base), ".") segments := strings.Split(prefix, ".") for i, j := 0, len(segments)-1; i < j; i, j = i+1, j-1 { segments[i], segments[j] = segments[j], segments[i] } if len(segments) == 0 { return nil, nil } glog.V(4).Infof("Answering query %s:%t", dnsName, exact) switch base := segments[0]; base { case "pod": if len(segments) != 3 { return nil, nil } namespace, encodedIP := segments[1], segments[2] ip := convertDashIPToIP(encodedIP) if net.ParseIP(ip) == nil { return nil, nil } return []msg.Service{ { Host: ip, Port: 0, Priority: 10, Weight: 10, Ttl: 30, Key: msg.Path(buildDNSName(b.base, "pod", namespace, getHash(ip))), }, }, nil case "svc", "endpoints": if len(segments) < 3 { return nil, nil } namespace, name := segments[1], segments[2] svc, err := b.accessor.Services(namespace).Get(name) if err != nil { if errors.IsNotFound(err) && b.fallback != nil { if fallback, ok := b.fallback(prefix, exact); ok { return b.Records(fallback+b.base, exact) } } return nil, err } // no portalIP and not headless, no DNS if len(svc.Spec.ClusterIP) == 0 { return nil, nil } subdomain := buildDNSName(b.base, base, namespace, name) endpointPrefix := base == "endpoints" retrieveEndpoints := endpointPrefix || (len(segments) > 3 && segments[3] == "_endpoints") // if has a portal IP and looking at svc if svc.Spec.ClusterIP != kapi.ClusterIPNone && !retrieveEndpoints { defaultService := msg.Service{ Host: svc.Spec.ClusterIP, Port: 0, Priority: 10, Weight: 10, Ttl: 30, } defaultHash := getHash(defaultService.Host) defaultName := buildDNSName(subdomain, defaultHash) defaultService.Key = msg.Path(defaultName) if len(svc.Spec.Ports) == 0 { return []msg.Service{defaultService}, nil } services := []msg.Service{} if len(segments) == 3 { for _, p := range svc.Spec.Ports { port := p.Port if port == 0 { port = p.TargetPort.IntVal } if port == 0 { continue } if len(p.Protocol) == 0 { p.Protocol = kapi.ProtocolTCP } portName := p.Name if len(portName) == 0 { portName = fmt.Sprintf("unknown-port-%d", port) } keyName := buildDNSName(subdomain, "_"+strings.ToLower(string(p.Protocol)), "_"+portName) services = append(services, msg.Service{ Host: svc.Spec.ClusterIP, Port: port, Priority: 10, Weight: 10, Ttl: 30, Key: msg.Path(keyName), }, ) } } if len(services) == 0 { services = append(services, defaultService) } glog.V(4).Infof("Answered %s:%t with %#v", dnsName, exact, services) return services, nil } // return endpoints endpoints, err := b.endpoints.Endpoints(namespace).Get(name) if err != nil { return nil, err } services := make([]msg.Service, 0, len(endpoints.Subsets)*4) for _, s := range endpoints.Subsets { for _, a := range s.Addresses { defaultService := msg.Service{ Host: a.IP, Port: 0, Priority: 10, Weight: 10, Ttl: 30, } defaultHash := getHash(defaultService.Host) defaultName := buildDNSName(subdomain, defaultHash) defaultService.Key = msg.Path(defaultName) for _, p := range s.Ports { port := p.Port if port == 0 { continue } if len(p.Protocol) == 0 { p.Protocol = kapi.ProtocolTCP } portName := p.Name if len(portName) == 0 { portName = fmt.Sprintf("unknown-port-%d", port) } keyName := buildDNSName(subdomain, "_"+strings.ToLower(string(p.Protocol)), "_"+portName, defaultHash) services = append(services, msg.Service{ Host: a.IP, Port: port, Priority: 10, Weight: 10, Ttl: 30, Key: msg.Path(keyName), }) } if len(services) == 0 { services = append(services, defaultService) } } } glog.V(4).Infof("Answered %s:%t with %#v", dnsName, exact, services) return services, nil } return nil, nil }
// NSRecords returns NS records from etcd. func (s *server) NSRecords(q dns.Question, name string) (records []dns.RR, extra []dns.RR, err error) { path, star := msg.PathWithWildcard(name) r, err := get(s.client, path, true) if err != nil { return nil, nil, err } if !r.Node.Dir { // single element serv := new(msg.Service) if err := json.Unmarshal([]byte(r.Node.Value), serv); err != nil { s.config.log.Infof("failed to parse json: %s", err.Error()) return nil, nil, err } ip := net.ParseIP(serv.Host) ttl := s.calculateTtl(r.Node, serv) serv.Key = r.Node.Key serv.Ttl = ttl switch { case ip == nil: return nil, nil, fmt.Errorf("NS record must be an IP address") case ip.To4() != nil: serv.Host = msg.Domain(serv.Key) records = append(records, serv.NewNS(q.Name, serv.Host)) extra = append(extra, serv.NewA(serv.Host, ip.To4())) case ip.To4() == nil: serv.Host = msg.Domain(serv.Key) records = append(records, serv.NewNS(q.Name, serv.Host)) extra = append(extra, serv.NewAAAA(serv.Host, ip.To16())) } return records, extra, nil } sx, err := s.loopNodes(&r.Node.Nodes, strings.Split(msg.Path(name), "/"), star, nil) if err != nil || len(sx) == 0 { return nil, nil, err } for _, serv := range sx { ip := net.ParseIP(serv.Host) switch { case ip == nil: return nil, nil, fmt.Errorf("NS record must be an IP address") case ip.To4() != nil: serv.Host = msg.Domain(serv.Key) records = append(records, serv.NewNS(q.Name, serv.Host)) extra = append(extra, serv.NewA(serv.Host, ip.To4())) case ip.To4() == nil: serv.Host = msg.Domain(serv.Key) records = append(records, serv.NewNS(q.Name, serv.Host)) extra = append(extra, serv.NewAAAA(serv.Host, ip.To16())) } } return records, extra, nil }
func (s *server) AddressRecords(q dns.Question, name string, previousRecords []dns.RR) (records []dns.RR, err error) { path, star := msg.PathWithWildcard(name) r, err := get(s.client, path, true) if err != nil { return nil, err } if !r.Node.Dir { // single element serv := new(msg.Service) if err := json.Unmarshal([]byte(r.Node.Value), serv); err != nil { s.config.log.Infof("failed to parse json: %s", err.Error()) return nil, err } ip := net.ParseIP(serv.Host) ttl := s.calculateTtl(r.Node, serv) serv.Ttl = ttl serv.Key = r.Node.Key switch { case ip == nil: // Try to resolve as CNAME if it's not an IP. newRecord := serv.NewCNAME(q.Name, dns.Fqdn(serv.Host)) if len(previousRecords) > 7 { s.config.log.Errorf("CNAME lookup limit of 8 exceeded for %s", newRecord) return nil, fmt.Errorf("exceeded CNAME lookup limit") } if s.isDuplicateCNAME(newRecord, previousRecords) { s.config.log.Errorf("CNAME loop detected for record %s", newRecord) return nil, fmt.Errorf("detected CNAME loop") } records = append(records, newRecord) nextRecords, err := s.AddressRecords(dns.Question{Name: dns.Fqdn(serv.Host), Qtype: q.Qtype, Qclass: q.Qclass}, strings.ToLower(dns.Fqdn(serv.Host)), append(previousRecords, newRecord)) if err != nil { // This means we can not complete the CNAME, this is OK, but // if we return an error this will trigger an NXDOMAIN. // We also don't want to return the CNAME, because of the // no other data rule. So return nothing and let NODATA // kick in (via a hack). return records, fmt.Errorf("incomplete CNAME chain") } records = append(records, nextRecords...) case ip.To4() != nil && q.Qtype == dns.TypeA: records = append(records, serv.NewA(q.Name, ip.To4())) case ip.To4() == nil && q.Qtype == dns.TypeAAAA: records = append(records, serv.NewAAAA(q.Name, ip.To16())) } return records, nil } nodes, err := s.loopNodes(&r.Node.Nodes, strings.Split(msg.Path(name), "/"), star, nil) if err != nil { s.config.log.Infof("failed to parse json: %s", err.Error()) return nil, err } for _, serv := range nodes { ip := net.ParseIP(serv.Host) switch { case ip == nil: // TODO: deduplicate with above code // Try to resolve as CNAME if it's not an IP. newRecord := serv.NewCNAME(q.Name, dns.Fqdn(serv.Host)) if len(previousRecords) > 7 { s.config.log.Errorf("CNAME lookup limit of 8 exceeded for %s", newRecord) return nil, fmt.Errorf("exceeded CNAME lookup limit") } if s.isDuplicateCNAME(newRecord, previousRecords) { s.config.log.Errorf("CNAME loop detected for record %s", newRecord) return nil, fmt.Errorf("detected CNAME loop") } records = append(records, newRecord) nextRecords, err := s.AddressRecords(dns.Question{Name: dns.Fqdn(serv.Host), Qtype: q.Qtype, Qclass: q.Qclass}, strings.ToLower(dns.Fqdn(serv.Host)), append(previousRecords, newRecord)) if err != nil { // This means we can not complete the CNAME, this is OK, but // if we return an error this will trigger an NXDOMAIN. // We also don't want to return the CNAME, because of the // no other data rule. So return nothing and let NODATA // kick in (via a hack). return records, fmt.Errorf("incomplete CNAME chain") } records = append(records, nextRecords...) case ip.To4() != nil && q.Qtype == dns.TypeA: records = append(records, serv.NewA(q.Name, ip.To4())) case ip.To4() == nil && q.Qtype == dns.TypeAAAA: records = append(records, serv.NewAAAA(q.Name, ip.To16())) } } if s.config.RoundRobin { switch l := len(records); l { case 2: if dns.Id()%2 == 0 { records[0], records[1] = records[1], records[0] } default: // Do a minimum of l swap, maximum of 4l swaps for j := 0; j < l*(int(dns.Id())%4+1); j++ { q := int(dns.Id()) % l p := int(dns.Id()) % l if q == p { p = (p + 1) % l } records[q], records[p] = records[p], records[q] } } } return records, nil }