feat: initial webssh tooling

2026-08-13 07:06:51 +00:00 · 2025-05-30 19:35:47 -04:00
parent f6d8ad25e1
commit 7dfcbef774
16 changed files with 792 additions and 83 deletions
@@ -0,0 +1,161 @@
+package sshutil
+
+import (
+	"context"
+	"errors"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/tale/headplane/agent/internal/tsnet"
+	"github.com/tale/headplane/agent/internal/util"
+	"golang.org/x/crypto/ssh"
+)
+
+type SshConnectParams struct {
+	Hostname string
+	Port     int
+	Username string
+	Id 	 string
+}
+
+func dialAndValidateTailscaleSSH(agent *tsnet.TSAgent, params SshConnectParams) (*ssh.Client, error) {
+	log := util.GetLogger()
+
+	addr := strings.Join([]string{params.Hostname, ":", strconv.Itoa(params.Port)}, "")
+
+	log.Debug("Attempting to dial %s via Tailscale SSH", addr)
+	conn, err := agent.Dial(context.Background(), "tcp", addr)
+	if err != nil {
+		log.Error("Failed to connect to Tailscale SSH: %s", err)
+		return nil, err
+	}
+
+	log.Debug("Connected to Tailscale SSH at %s", addr)
+	config := &ssh.ClientConfig{
+		User: params.Username,
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+	}
+
+	clientConn, chans, reqs, err := ssh.NewClientConn(conn, addr, config)
+	if err != nil {
+		log.Error("Failed to create SSH client connection: %s", err)
+		conn.Close()
+		return nil, err
+	}
+
+	client := ssh.NewClient(clientConn, chans, reqs)
+	sVer := string(client.ServerVersion())
+
+	if !strings.Contains(sVer, "Tailscale") {
+		log.Error("Connected to non-Tailscale SSH server: %s", sVer)
+		conn.Close()
+		return nil, errors.New("not a Tailscale SSH server")
+	}
+
+	log.Info("Connected to SSH server running %s at %s", client.ServerVersion(), addr)
+	return client, nil
+}
+
+func bindStdinToFd(sess *ssh.Session, fd int) error {
+	log := util.GetLogger()
+
+	sshIn := os.NewFile(uintptr(fd), "sshInput")
+	if sshIn == nil {
+		log.Error("Failed to create file from stdin fd %d", fd)
+		return errors.New("failed to create file from stdin fd")
+	}
+
+	stdin, err := sess.StdinPipe()
+	if err != nil {
+		log.Error("Failed to get stdin pipe: %s", err)
+		return err
+	}
+
+	go io.Copy(stdin, sshIn) // From Node → SSH session
+	return nil
+}
+
+func bindStdoutToFd(sess *ssh.Session, fd int) error {
+	log := util.GetLogger()
+
+	sshOut := os.NewFile(uintptr(fd), "sshOutput")
+	if sshOut == nil {
+		log.Error("Failed to create file from stdout fd %d", fd)
+		return errors.New("failed to create file from stdout fd")
+	}
+
+	stdout, err := sess.StdoutPipe()
+	if err != nil {
+		log.Error("Failed to get stdout pipe: %s", err)
+		return err
+	}
+
+	go io.Copy(sshOut, stdout) // From SSH → Node
+	return nil
+}
+
+func OpenSshPty(agent *tsnet.TSAgent, params SshConnectParams) (*ssh.Client, error) {
+	log := util.GetLogger()
+
+	if agent == nil {
+		log.Error("Tailscale agent is nil")
+		return nil, errors.New("tailscale agent is nil")
+	}
+
+	if params.Hostname == "" || params.Port <= 0 || params.Username == "" {
+		log.Error("Invalid SSH connection parameters: %+v", params)
+		return nil, errors.New("invalid SSH connection parameters")
+	}
+
+	client, err := dialAndValidateTailscaleSSH(agent, params)
+	if err != nil {
+		log.Error("Failed to open SSH pty: %s", err)
+		return nil, err
+	}
+
+	go func() {
+	sess, err := client.NewSession()
+	if err != nil {
+		log.Error("Failed to create new SSH session: %s", err)
+		client.Close()
+	}
+
+	modes := ssh.TerminalModes{
+		ssh.ECHO:          1, // enable echoing
+		ssh.TTY_OP_ISPEED: 14400,
+		ssh.TTY_OP_OSPEED: 14400,
+	}
+
+	if err := sess.RequestPty("xterm-256color", 80, 40, modes); err != nil {
+		log.Error("Failed to request PTY: %s", err)
+		client.Close()
+	}
+
+	ctx := addSession(params.Id, sess)
+	go func() {
+		for data := range ctx.InputCh {
+			if _, err := ctx.Stdin.Write(data); err != nil {
+				log.Error("Failed to write to SSH stdin: %s", err)
+				return
+			}
+		}
+	}();
+
+	if err := sess.Shell(); err != nil {
+		log.Error("Failed to start shell: %s", err)
+		client.Close()
+	}
+
+
+	log.Info("Successfully opened SSH pty for %s@%s:%d", params.Username, params.Hostname, params.Port)
+	go streamSSHOutput(params.Id, ctx.Stdout, os.NewFile(4, "sshOutput"))
+		sess.Wait();
+		sess.Close();
+		log.Info("SSH session %s closed (goSide)", params.Id)
+		RemoveSession(params.Id)
+	}()
+
+	return client, nil
+}