Terminal: SSH to NAS host instead of container shell

- Rewrite terminal.py to use asyncssh instead of pty/fork
- Add SSH key pair for dashboard container auth
- Mount SSH key and add SSH config vars in docker-compose
- Install openssh-client in Dockerfile
- Add asyncssh to requirements.txt

dashboard/backend/config.py

@@ -14,3 +14,8 @@ ADMIN_USER = os.environ.get("ADMIN_USER", "admin")
 # Default hash for "admin" using pbkdf2_sha256 scheme to avoid bcrypt compat issues
 ADMIN_PASSWORD_HASH = os.environ.get("ADMIN_PASSWORD_HASH", "$pbkdf2-sha256$29000$25tTKoUQIgQghLC2ds4ZYw$H/fCb3H5wmOkwj6l6KrVlmns0TWfzKPOrG3sgVDR.eg")
 TOTP_SECRET = os.environ.get("TOTP_SECRET", "JBSWY3DPEHPK3PXP") # Base32 encoded secretans 2FA disabled by default
+
+# SSH terminal
+SSH_HOST = os.environ.get("SSH_HOST", "host.docker.internal")
+SSH_USER = os.environ.get("SSH_USER", "zjgump")
+SSH_KEY_PATH = os.environ.get("SSH_KEY_PATH", "/app/ssh/id_ed25519")

dashboard/backend/requirements.txt

@@ -7,3 +7,4 @@ psutil==6.1.0
 pyjwt==2.8.0
 passlib==1.7.4
 pyotp==2.9.0
+asyncssh==2.17.0

dashboard/backend/routers/terminal.py

@@ -1,18 +1,12 @@
 import asyncio
-import os
-import pty
-import signal
 import struct
-import fcntl
-import termios
-import select
 from fastapi import WebSocket, WebSocketDisconnect, Query
+import asyncssh
 import jwt
 import config
 
 
 async def ws_endpoint(websocket: WebSocket, token: str = Query("")):
-    # Verify auth token
     try:
         payload = jwt.decode(token, config.SECRET_KEY, algorithms=[config.ALGORITHM])
         if payload.get("sub") != config.ADMIN_USER:
@@ -23,52 +17,47 @@ async def ws_endpoint(websocket: WebSocket, token: str = Query("")):
         return
 
     await websocket.accept()
-    master_fd, slave_fd = pty.openpty()
-    pid = os.fork()
-
-    if pid == 0:
-        os.close(master_fd)
-        os.setsid()
-        os.dup2(slave_fd, 0)
-        os.dup2(slave_fd, 1)
-        os.dup2(slave_fd, 2)
-        os.close(slave_fd)
-        os.execvp("/bin/bash", ["/bin/bash"])
-
-    os.close(slave_fd)
-
-    async def read_pty():
-        try:
-            while True:
-                await asyncio.sleep(0.01)
-                r, _, _ = select.select([master_fd], [], [], 0)
-                if r:
-                    data = os.read(master_fd, 4096)
-                    if not data:
-                        break
-                    await websocket.send_bytes(data)
-        except (OSError, WebSocketDisconnect):
-            pass
-
-    read_task = asyncio.create_task(read_pty())
 
     try:
-        while True:
-            msg = await websocket.receive()
-            if "bytes" in msg and msg["bytes"]:
-                data = msg["bytes"]
-                if data[0:1] == b"\x01" and len(data) == 5:
-                    cols = struct.unpack("!H", data[1:3])[0]
-                    rows = struct.unpack("!H", data[3:5])[0]
-                    fcntl.ioctl(master_fd, termios.TIOCSWINSZ, struct.pack("HHHH", rows, cols, 0, 0))
-                else:
-                    os.write(master_fd, data)
-            elif "text" in msg and msg["text"]:
-                os.write(master_fd, msg["text"].encode())
-    except WebSocketDisconnect:
-        pass
+        conn = await asyncssh.connect(
+            config.SSH_HOST, username=config.SSH_USER,
+            client_keys=[config.SSH_KEY_PATH], known_hosts=None,
+        )
+    except Exception:
+        await websocket.close(code=1011, reason="SSH connection failed")
+        return
+
+    try:
+        chan, session = await conn.create_session(
+            asyncssh.SSHClientProcess, term_type="xterm-256color",
+            term_size=(80, 24),
+        )
+
+        async def read_ssh():
+            try:
+                async for data in chan.stdout:
+                    await websocket.send_bytes(data.encode() if isinstance(data, str) else data)
+            except (asyncssh.Error, WebSocketDisconnect):
+                pass
+
+        read_task = asyncio.create_task(read_ssh())
+
+        try:
+            while True:
+                msg = await websocket.receive()
+                if "bytes" in msg and msg["bytes"]:
+                    data = msg["bytes"]
+                    if data[0:1] == b"\x01" and len(data) == 5:
+                        cols = struct.unpack("!H", data[1:3])[0]
+                        rows = struct.unpack("!H", data[3:5])[0]
+                        chan.change_terminal_size(cols, rows)
+                    else:
+                        chan.write(data.decode("utf-8", errors="replace"))
+                elif "text" in msg and msg["text"]:
+                    chan.write(msg["text"])
+        except WebSocketDisconnect:
+            pass
+        finally:
+            read_task.cancel()
     finally:
-        read_task.cancel()
-        os.close(master_fd)
-        os.kill(pid, signal.SIGTERM)
-        os.waitpid(pid, 0)
+        conn.close()