Serge Bazanski | 044386d | 2021-05-24 15:10:08 +0200 | [diff] [blame] | 1 | package main |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "flag" |
| 7 | "fmt" |
| 8 | "net" |
| 9 | "os" |
| 10 | "os/signal" |
| 11 | "strings" |
| 12 | |
| 13 | "github.com/golang/glog" |
| 14 | v1 "k8s.io/apimachinery/pkg/apis/meta/v1" |
| 15 | |
| 16 | "code.hackerspace.pl/hscloud/cluster/identd/ident" |
| 17 | "code.hackerspace.pl/hscloud/cluster/identd/kubenat" |
| 18 | "code.hackerspace.pl/hscloud/go/mirko" |
| 19 | ) |
| 20 | |
| 21 | func init() { |
| 22 | flag.Set("logtostderr", "true") |
| 23 | } |
| 24 | |
| 25 | var ( |
| 26 | flagIdentdListen = "127.0.0.1:8113" |
| 27 | flagContainerdSocket = "/var/run/containerd/containerd.sock" |
| 28 | flagConntrackProc = "/proc/net/nf_conntrack" |
| 29 | flagPodName = "" |
| 30 | flagPodNamespace = "" |
| 31 | ) |
| 32 | |
| 33 | func main() { |
| 34 | flag.StringVar(&flagIdentdListen, "identd_listen", flagIdentdListen, "Address at which to listen for incoming ident protocol connections") |
| 35 | flag.StringVar(&flagContainerdSocket, "identd_containerd_socket", flagContainerdSocket, "Containerd gRPC socket path") |
| 36 | flag.StringVar(&flagConntrackProc, "identd_conntrack_proc", flagConntrackProc, "Conntrack procfs file") |
| 37 | flag.StringVar(&flagPodName, "identd_pod_name", flagPodName, "Name of this pod, if on k8s. Needed for public IP resolution.") |
| 38 | flag.StringVar(&flagPodNamespace, "identd_pod_namespace", flagPodNamespace, "Namespace where this pod is running, if on k8s. Needed for public IP resolution.") |
| 39 | flag.Parse() |
| 40 | |
| 41 | ctx, ctxC := context.WithCancel(context.Background()) |
| 42 | |
| 43 | resolver, err := kubenat.NewResolver(ctx, flagConntrackProc, flagContainerdSocket) |
| 44 | if err != nil { |
| 45 | glog.Exitf("Could not start kubenet resolver: %v", err) |
| 46 | } |
| 47 | |
| 48 | var localIP net.IP |
| 49 | |
| 50 | localIPStr, _, err := net.SplitHostPort(flagIdentdListen) |
| 51 | if err != nil { |
| 52 | glog.Warningf("Could not parse identd listen flag %q", flagIdentdListen) |
| 53 | } else { |
| 54 | localIP = net.ParseIP(localIPStr) |
| 55 | if localIP == nil || !localIP.IsGlobalUnicast() { |
| 56 | glog.Warningf("Could not parse unicast IP from identd flag %q", localIPStr) |
| 57 | localIP = nil |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | if localIP == nil { |
| 62 | glog.Infof("Could not figure out public IP address for identd, attempting to retrieve from k8s...") |
| 63 | cs := mirko.KubernetesClient() |
| 64 | if cs == nil { |
| 65 | glog.Exitf("Not in k8s and identd_listen set to invalid public IP address - exiting.") |
| 66 | } |
| 67 | if flagPodName == "" { |
| 68 | glog.Exitf("identd_pod_name must be set") |
| 69 | } |
| 70 | if flagPodNamespace == "" { |
| 71 | glog.Exitf("identd_pod_namespace must be set") |
| 72 | } |
| 73 | pod, err := cs.CoreV1().Pods(flagPodNamespace).Get(ctx, flagPodName, v1.GetOptions{}) |
| 74 | if err != nil { |
| 75 | glog.Exitf("Could not find pod %q in namespace %q: %v", flagPodName, flagPodNamespace, err) |
| 76 | } |
| 77 | ipStr := pod.Status.HostIP |
| 78 | if ipStr == "" { |
| 79 | glog.Exitf("HostIP in status of pod %q is empty", flagPodName) |
| 80 | } |
| 81 | glog.Infof("Resolved k8s node IP to %s", ipStr) |
| 82 | |
| 83 | localIP = net.ParseIP(ipStr) |
| 84 | if localIP == nil { |
| 85 | glog.Exitf("HostIP in status of pod %q is unparseable", flagPodName, ipStr) |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | glog.Infof("Will respond to identd queries on %s...", localIP) |
| 90 | s := &service{ |
| 91 | resolver: resolver, |
| 92 | localIP: localIP, |
| 93 | } |
| 94 | |
| 95 | lis, err := net.Listen("tcp", flagIdentdListen) |
| 96 | if err != nil { |
| 97 | glog.Exitf("Could not listen for identd: %v", err) |
| 98 | } |
| 99 | isrv := ident.NewServer() |
| 100 | isrv.HandleFunc(s.handleIdent) |
| 101 | go func() { |
| 102 | glog.Infof("Starting identd on %s...", flagIdentdListen) |
| 103 | err := isrv.Serve(lis) |
| 104 | if err != nil { |
| 105 | glog.Exitf("identd Serve: %v", err) |
| 106 | } |
| 107 | }() |
| 108 | |
| 109 | signalChan := make(chan os.Signal, 1) |
| 110 | signal.Notify(signalChan, os.Interrupt) |
| 111 | go func() { |
| 112 | <-signalChan |
| 113 | ctxC() |
| 114 | }() |
| 115 | |
| 116 | <-ctx.Done() |
| 117 | glog.Infof("Stopping identd...") |
| 118 | isrv.Stop() |
| 119 | lis.Close() |
| 120 | } |
| 121 | |
| 122 | type service struct { |
| 123 | resolver *kubenat.Resolver |
| 124 | localIP net.IP |
| 125 | } |
| 126 | |
| 127 | func (s *service) handleIdent(ctx context.Context, w ident.ResponseWriter, r *ident.Request) { |
| 128 | clientIPStr, _, err := net.SplitHostPort(r.ClientAddress.String()) |
| 129 | if err != nil { |
| 130 | glog.Errorf("Unparseable ClientAddres %q", r.ClientAddress) |
| 131 | w.SendError(ident.UnknownError) |
| 132 | return |
| 133 | } |
| 134 | clientIP := net.ParseIP(clientIPStr) |
| 135 | if clientIP == nil { |
| 136 | glog.Errorf("Unparseable ClientAddres IP %q", r.ClientAddress) |
| 137 | w.SendError(ident.UnknownError) |
| 138 | return |
| 139 | } |
| 140 | |
| 141 | t4 := kubenat.Tuple4{ |
| 142 | RemoteIP: clientIP, |
| 143 | RemotePort: r.ClientPort, |
| 144 | LocalIP: s.localIP, |
| 145 | LocalPort: r.ServerPort, |
| 146 | } |
| 147 | glog.Infof("Running query for %s...", t4.String()) |
| 148 | info, err := s.resolver.ResolvePod(ctx, &t4) |
| 149 | if err != nil { |
| 150 | glog.Errorf("ResolvePod(%q): %v", t4.String(), err) |
| 151 | w.SendError(ident.NoUser) |
| 152 | return |
| 153 | } |
| 154 | |
| 155 | ns := info.KubernetesNamespace |
| 156 | pod := info.Name |
| 157 | |
| 158 | if ns == "matrix" && strings.HasPrefix(pod, "appservice-irc-") { |
| 159 | target := net.JoinHostPort(info.PodIP.String(), "1113") |
| 160 | clientPort := r.ClientPort |
| 161 | serverPort := info.PodTranslatedPort |
| 162 | glog.Infof("Forwarding to appservice-irc at %q, clientPort: %d, serverPort: %d", target, clientPort, serverPort) |
| 163 | res, err := ident.Query(ctx, target, clientPort, serverPort) |
| 164 | if err != nil { |
| 165 | var identErr *ident.IdentError |
| 166 | if errors.As(err, &identErr) { |
| 167 | glog.Infof("appservice-irc: %s", identErr.Inner) |
| 168 | w.SendError(identErr.Inner) |
| 169 | } else { |
| 170 | glog.Infof("appservice-irc: error: %v", err) |
| 171 | w.SendError(ident.UnknownError) |
| 172 | } |
| 173 | } else { |
| 174 | glog.Infof("Response from appservice-irc: %q", res.UserID) |
| 175 | w.SendIdent(&ident.IdentResponse{ |
| 176 | UserID: res.UserID, |
| 177 | }) |
| 178 | } |
| 179 | return |
| 180 | } |
| 181 | // default to kns-* |
| 182 | user := fmt.Sprintf("kns-%s", ns) |
| 183 | // q3k's old personal namespace. |
| 184 | if ns == "q3k" { |
| 185 | user = "q3k" |
| 186 | } |
| 187 | // personal-* namespaces. |
| 188 | if strings.HasPrefix(ns, "personal-") { |
| 189 | user = strings.TrimPrefix(ns, "personal-") |
| 190 | } |
| 191 | glog.Infof("Returning %q (from %q) for %q", user, ns, t4.String()) |
| 192 | w.SendIdent(&ident.IdentResponse{ |
| 193 | UserID: user, |
| 194 | }) |
| 195 | } |