Add coder tunnel command

Author: f0ssel

internal/cmd/agent.go

@@ -86,11 +86,11 @@ coder agent start https://my-coder.com
 			ctx, cancelFunc := context.WithTimeout(ctx, time.Second*15)
 			defer cancelFunc()
 			log.Info(ctx, "connecting to broker", slog.F("url", u.String()))
-			conn, res, err := websocket.Dial(ctx, u.String(), nil)
+			// nolint: bodyclose
+			conn, _, err := websocket.Dial(ctx, u.String(), nil)
 			if err != nil {
 				return fmt.Errorf("dial: %w", err)
 			}
-			_ = res.Body.Close()
 			nc := websocket.NetConn(context.Background(), conn, websocket.MessageBinary)
 			session, err := yamux.Server(nc, nil)
 			if err != nil {

internal/cmd/cmd.go

@@ -38,6 +38,7 @@ func Make() *cobra.Command {
 		providersCmd(),
 		genDocsCmd(app),
 		agentCmd(),
+		tunnelCmd(),
 	)
 	app.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "show verbose output")
 	return app

internal/cmd/tunnel.go

@@ -0,0 +1,272 @@
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+	"os"
+	"strconv"
+	"time"
+
+	"cdr.dev/slog"
+	"cdr.dev/slog/sloggers/sloghuman"
+	"github.com/pion/webrtc/v3"
+	"github.com/spf13/cobra"
+	"golang.org/x/xerrors"
+	"nhooyr.io/websocket"
+
+	"cdr.dev/coder-cli/internal/x/xcobra"
+	"cdr.dev/coder-cli/internal/x/xwebrtc"
+	"cdr.dev/coder-cli/pkg/proto"
+)
+
+func tunnelCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "tunnel [workspace_name] [workspace_port] [localhost_port]",
+		Args:  xcobra.ExactArgs(3),
+		Short: "proxies a port on the workspace to localhost",
+		Long:  "proxies a port on the workspace to localhost",
+		Example: `# run a tcp tunnel from the workspace on port 3000 to localhost:3000
+
+coder tunnel my-dev 3000 3000
+`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			ctx := context.Background()
+			log := slog.Make(sloghuman.Sink(os.Stderr))
+
+			remotePort, err := strconv.ParseUint(args[1], 10, 16)
+			if err != nil {
+				log.Fatal(ctx, "parse remote port", slog.Error(err))
+			}
+
+			var localPort uint64
+			if args[2] != "stdio" {
+				localPort, err = strconv.ParseUint(args[2], 10, 16)
+				if err != nil {
+					log.Fatal(ctx, "parse local port", slog.Error(err))
+				}
+			}
+
+			sdk, err := newClient(ctx)
+			if err != nil {
+				return err
+			}
+			baseURL := sdk.BaseURL()
+
+			envs, err := sdk.Environments(ctx)
+			if err != nil {
+				return err
+			}
+
+			var envID string
+			for _, env := range envs {
+				if env.Name == args[0] {
+					envID = env.ID
+					break
+				}
+			}
+			if envID == "" {
+				return xerrors.Errorf("No workspace found by name '%s'", args[0])
+			}
+
+			c := &client{
+				id:         envID,
+				stdio:      args[2] == "stdio",
+				localPort:  uint16(localPort),
+				remotePort: uint16(remotePort),
+				ctx:        context.Background(),
+				logger:     log,
+				brokerAddr: baseURL.String(),
+				token:      sdk.Token(),
+			}
+
+			err = c.start()
+			if err != nil {
+				log.Fatal(ctx, err.Error())
+			}
+
+			return nil
+		},
+	}
+
+	return cmd
+}
+
+type client struct {
+	ctx        context.Context
+	brokerAddr string
+	token      string
+	logger     slog.Logger
+	id         string
+	remotePort uint16
+	localPort  uint16
+	stdio      bool
+}
+
+func (c *client) start() error {
+	url := fmt.Sprintf("%s%s%s%s%s", c.brokerAddr, "/api/private/envagent/", c.id, "/connect?session_token=", c.token)
+	c.logger.Info(c.ctx, "connecting to broker", slog.F("url", url))
+
+	conn, _, err := websocket.Dial(c.ctx, url, nil)
+	if err != nil {
+		return fmt.Errorf("dial: %w", err)
+	}
+	nconn := websocket.NetConn(context.Background(), conn, websocket.MessageBinary)
+
+	rtc, err := xwebrtc.NewPeerConnection()
+	if err != nil {
+		return fmt.Errorf("create connection: %w", err)
+	}
+
+	rtc.OnNegotiationNeeded(func() {
+		c.logger.Debug(context.Background(), "negotiation needed...")
+	})
+
+	rtc.OnConnectionStateChange(func(pcs webrtc.PeerConnectionState) {
+		c.logger.Info(context.Background(), "connection state changed", slog.F("state", pcs))
+	})
+
+	channel, err := xwebrtc.NewProxyDataChannel(rtc, "forwarder", "tcp", c.remotePort)
+	if err != nil {
+		return fmt.Errorf("create data channel: %w", err)
+	}
+	flushCandidates := proto.ProxyICECandidates(rtc, nconn)
+
+	localDesc, err := rtc.CreateOffer(&webrtc.OfferOptions{})
+	if err != nil {
+		return fmt.Errorf("create offer: %w", err)
+	}
+
+	err = rtc.SetLocalDescription(localDesc)
+	if err != nil {
+		return fmt.Errorf("set local desc: %w", err)
+	}
+	flushCandidates()
+
+	c.logger.Debug(context.Background(), "writing offer")
+	b, _ := json.Marshal(&proto.Message{
+		Offer: &localDesc,
+	})
+	_, err = nconn.Write(b)
+	if err != nil {
+		return fmt.Errorf("write offer: %w", err)
+	}
+
+	go func() {
+		err = xwebrtc.WaitForDataChannelOpen(context.Background(), channel)
+		if err != nil {
+			c.logger.Fatal(context.Background(), "waiting for data channel open", slog.Error(err))
+		}
+		_ = conn.Close(websocket.StatusNormalClosure, "rtc connected")
+	}()
+
+	decoder := json.NewDecoder(nconn)
+	for {
+		var msg proto.Message
+		err = decoder.Decode(&msg)
+		if err == io.EOF {
+			break
+		}
+		if websocket.CloseStatus(err) == websocket.StatusNormalClosure {
+			break
+		}
+		if err != nil {
+			return fmt.Errorf("read msg: %w", err)
+		}
+		if msg.Candidate != "" {
+			c.logger.Debug(context.Background(), "accepted ice candidate", slog.F("candidate", msg.Candidate))
+			err = proto.AcceptICECandidate(rtc, &msg)
+			if err != nil {
+				return fmt.Errorf("accept ice: %w", err)
+			}
+		}
+		if msg.Answer != nil {
+			c.logger.Debug(context.Background(), "got answer", slog.F("answer", msg.Answer))
+			err = rtc.SetRemoteDescription(*msg.Answer)
+			if err != nil {
+				return fmt.Errorf("set remote: %w", err)
+			}
+		}
+	}
+
+	// Once we're open... let's test out the ping.
+	pingProto := "ping"
+	pingChannel, err := rtc.CreateDataChannel("pinger", &webrtc.DataChannelInit{
+		Protocol: &pingProto,
+	})
+	if err != nil {
+		return fmt.Errorf("create ping channel")
+	}
+	pingChannel.OnOpen(func() {
+		defer func() {
+			_ = pingChannel.Close()
+		}()
+		t1 := time.Now()
+		rw, _ := pingChannel.Detach()
+		defer func() {
+			_ = rw.Close()
+		}()
+		_, _ = rw.Write([]byte("hello"))
+		b := make([]byte, 64)
+		_, _ = rw.Read(b)
+		c.logger.Info(c.ctx, "your latency directly to the agent", slog.F("ms", time.Since(t1).Milliseconds()))
+	})
+
+	if c.stdio {
+		// At this point the RTC is connected and data channel is opened...
+		rw, err := channel.Detach()
+		if err != nil {
+			return fmt.Errorf("detach channel: %w", err)
+		}
+		go func() {
+			_, _ = io.Copy(rw, os.Stdin)
+		}()
+		_, err = io.Copy(os.Stdout, rw)
+		if err != nil {
+			return fmt.Errorf("copy: %w", err)
+		}
+		return nil
+	}
+
+	listener, err := net.Listen("tcp", fmt.Sprintf("localhost:%d", c.localPort))
+	if err != nil {
+		return fmt.Errorf("listen: %w", err)
+	}
+
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			return fmt.Errorf("accept: %w", err)
+		}
+		go func() {
+			defer func() {
+				_ = conn.Close()
+			}()
+			channel, err := xwebrtc.NewProxyDataChannel(rtc, "forwarder", "tcp", c.remotePort)
+			if err != nil {
+				c.logger.Warn(context.Background(), "create data channel for proxying", slog.Error(err))
+				return
+			}
+			defer func() {
+				_ = channel.Close()
+			}()
+			err = xwebrtc.WaitForDataChannelOpen(context.Background(), channel)
+			if err != nil {
+				c.logger.Warn(context.Background(), "wait for data channel open", slog.Error(err))
+				return
+			}
+			rw, err := channel.Detach()
+			if err != nil {
+				c.logger.Warn(context.Background(), "detach channel", slog.Error(err))
+				return
+			}
+
+			go func() {
+				_, _ = io.Copy(conn, rw)
+			}()
+			_, _ = io.Copy(rw, conn)
+		}()
+	}
+}