feat: Implement initial client application with TUI for SSH tunnel management and monitoring.

cmd/client/main.go

@@ -35,6 +35,7 @@ func main() {
 	localPort := flag.String("local", "8080", "Local port to expose")
 	serverAddrFlag := flag.String("server", "", "Grokway server address")
 	tokenFlag := flag.String("token", "", "Authentication token (overrides config)")
+	hostHeaderFlag := flag.String("host-header", "", "Custom Host header to send to local service")
 	flag.Parse()
 
 	// Load config
@@ -56,7 +57,7 @@ func main() {
 		serverAddr = "localhost:2222"
 	}
 
-	m := tui.InitialModel(*localPort, serverAddr, authToken)
+	m := tui.InitialModel(*localPort, serverAddr, authToken, *hostHeaderFlag)
 	p := tea.NewProgram(m, tea.WithAltScreen())
 
 	if _, err := p.Run(); err != nil {

internal/tui/model.go

@@ -68,8 +68,8 @@ type LogMsg string
 type MetricMsg int64
 type ClearCopiedMsg struct{}
 
-func InitialModel(localPort, serverAddr, authToken string) Model {
-	c := tunnel.NewClient(serverAddr, localPort, authToken)
+func InitialModel(localPort, serverAddr, authToken, hostHeader string) Model {
+	c := tunnel.NewClient(serverAddr, localPort, authToken, hostHeader)
 	return Model{
 		Client:   c,
 		LogLines: []string{},

internal/tunnel/client.go

@@ -23,6 +23,7 @@ type Client struct {
 	ServerAddr string
 	LocalPort  string
 	AuthToken  string
+	HostHeader string // New field for custom Host header
 	SSHClient  *ssh.Client
 	Listener   net.Listener
 	Events     chan string // Channel to send logs/events to TUI
@@ -30,11 +31,12 @@ type Client struct {
 	PublicURL  string      // PublicURL is the URL accessible from the internet
 }
 
-func NewClient(serverAddr, localPort, authToken string) *Client {
+func NewClient(serverAddr, localPort, authToken, hostHeader string) *Client {
 	return &Client{
 		ServerAddr: serverAddr,
 		LocalPort:  localPort,
 		AuthToken:  authToken,
+		HostHeader: hostHeader,
 		Events:     make(chan string, 10),
 		Metrics:    make(chan int64, 10),
 	}
@@ -129,18 +131,73 @@ func (c *Client) handleConnection(remoteConn net.Conn) {
 	// or use a bufio reader if we weren't doing a raw Copy.
 	// But io.Copy needs a reader.
 
-	// Create a buffer to read the first few bytes
-	buf := make([]byte, 1024)
+	// Read first chunk to inspect headers
+	buf := make([]byte, 8192) // Increased buffer for headers
+	remoteConn.SetReadDeadline(time.Now().Add(500 * time.Millisecond))
 	n, err := remoteConn.Read(buf)
-	if err != nil {
+	remoteConn.SetReadDeadline(time.Time{}) // Reset deadline
+
+	if err != nil && err != io.EOF && !os.IsTimeout(err) {
 		logToFile(fmt.Sprintf("Error reading from remote: %v", err))
 		return
 	}
+	if n == 0 {
+		return
+	}
 
 	payload := string(buf[:n])
 
-	// Try to parse rudimentary HTTP
+	// If it looks like HTTP, rewrite Host and add Proto headers
+	if strings.Contains(payload, "HTTP/") {
+		lines := strings.Split(payload, "\r\n")
+		var newLines []string
+
+		for _, line := range lines {
+			if strings.HasPrefix(strings.ToLower(line), "host:") {
+				if c.HostHeader != "" {
+					newLines = append(newLines, "Host: "+c.HostHeader)
+				} else {
+					// Default to localhost handling: keep original or set to localhost?
+					// Usually localhost:port is safest if user didn't specify.
+					newLines = append(newLines, "Host: localhost:"+c.LocalPort)
+				}
+				continue
+			}
+			newLines = append(newLines, line)
+		}
+
+		// Insert X-Forwarded-Proto if missing (prevents redirects loop)
+		if !strings.Contains(strings.ToLower(payload), "x-forwarded-proto:") {
+			// Find end of headers (empty line)
+			for i, line := range newLines {
+				if line == "" { // End of headers
+					// Insert before the empty line
+					finalHeaders := append(newLines[:i], "X-Forwarded-Proto: https")
+					finalHeaders = append(finalHeaders, newLines[i:]...)
+					newLines = finalHeaders
+					break
+				}
+			}
+		}
+
+		modifiedPayload := strings.Join(newLines, "\r\n")
+
+		// Log for debug
+		logToFile("Rewritten Headers:\n" + modifiedPayload)
+
+		// Send modified headers
+		localConn.Write([]byte(modifiedPayload))
+	} else {
+		// Not HTTP or couldn't parse, just forward as comes
+		localConn.Write(buf[:n])
+	}
+
+	// Try to parse rudimentary HTTP for TUI logs
 	// Format: METHOD PATH PROTOCOL
+
+	// We use the payload we just processed (or the original if not modified? No, logs should show original request usually,
+	// but here we have the payload string variable already.)
+
 	lines := strings.Split(payload, "\n")
 	if len(lines) > 0 {
 		firstLine := lines[0]
@@ -149,19 +206,14 @@ func (c *Client) handleConnection(remoteConn net.Conn) {
 			method := parts[0]
 			path := parts[1]
 			// Send structured log
-			c.Events <- fmt.Sprintf("HTTP|%s|%s|%d", method, path, 200) // Status is fake for now, acts as connection open
+			c.Events <- fmt.Sprintf("HTTP|%s|%s|%d", method, path, 200)
 		} else {
 			c.Events <- "TCP|||Connection"
 		}
 	}
 
-	// We need to write the bytes we read to the local connection first
-	localConn.Write(buf[:n])
-
 	// Bidirectional copy
 	// Calculate bytes?
-
-	// We can use a custom copy to track metrics
 	go func() {
 		n, _ := io.Copy(remoteConn, localConn)
 		c.Metrics <- n