improve ssh client class

custom_components/easy_computer_manager/computer/ssh_client.py

@@ -8,71 +8,88 @@ from custom_components.easy_computer_manager.computer import CommandOutput
 
 
 class SSHClient:
-    def __init__(self, host, username, password, port):
+    def __init__(self, host: str, username: str, password: Optional[str] = None, port: int = 22):
         self.host = host
         self.username = username
         self._password = password
         self.port = port
-        self._connection = None
+        self._connection: Optional[paramiko.SSHClient] = None
+
+    async def __aenter__(self):
+        await self.connect()
+        return self
+
+    async def __aexit__(self, exc_type, exc_value, traceback):
+        self.disconnect()
 
     async def connect(self, retried: bool = False, computer: Optional['Computer'] = None) -> None:
         """Open an SSH connection using Paramiko asynchronously."""
-        self.disconnect()
+        if self.is_connection_alive():
+            LOGGER.debug(f"Connection to {self.host} is already active.")
+            return
+
+        self.disconnect()  # Ensure any previous connection is closed
 
         loop = asyncio.get_running_loop()
-
-        try:
-            # Create the SSH client
         client = paramiko.SSHClient()
 
         # Set missing host key policy to automatically accept unknown host keys
-            # client.load_system_host_keys()
         client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
 
+        try:
             # Offload the blocking connect call to a thread
             await loop.run_in_executor(None, self._blocking_connect, client)
             self._connection = client
+            LOGGER.debug(f"Connected to {self.host}")
 
         except (OSError, paramiko.SSHException) as exc:
-            if retried:
-                await self.connect(retried=True)
-            else:
             LOGGER.debug(f"Failed to connect to {self.host}: {exc}")
+            if not retried:
+                LOGGER.debug(f"Retrying connection to {self.host}...")
+                await self.connect(retried=True)  # Retry only once
+
         finally:
-            if computer is not None:
-                if hasattr(computer, "initialized"):
+            if computer is not None and hasattr(computer, "initialized"):
                 computer.initialized = True
 
     def disconnect(self) -> None:
         """Close the SSH connection."""
-        if self._connection is not None:
+        if self._connection:
             self._connection.close()
+            LOGGER.debug(f"Disconnected from {self.host}")
         self._connection = None
 
-    def _blocking_connect(self, client):
+    def _blocking_connect(self, client: paramiko.SSHClient):
         """Perform the blocking SSH connection using Paramiko."""
         client.connect(
-            self.host,
+            hostname=self.host,
             username=self.username,
             password=self._password,
-            port=self.port
+            port=self.port,
+            look_for_keys=False,  # Set this to True if using private keys
+            allow_agent=False
         )
 
     async def execute_command(self, command: str) -> CommandOutput:
         """Execute a command on the SSH server asynchronously."""
-        try:
-            stdin, stdout, stderr = self._connection.exec_command(command)
-            exit_status = stdout.channel.recv_exit_status()
+        if not self.is_connection_alive():
+            LOGGER.debug(f"Connection to {self.host} is not alive. Reconnecting...")
+            await self.connect()
 
+        try:
+            # Offload command execution to avoid blocking
+            loop = asyncio.get_running_loop()
+            stdin, stdout, stderr = await loop.run_in_executor(None, self._connection.exec_command, command)
+
+            exit_status = stdout.channel.recv_exit_status()
             return CommandOutput(command, exit_status, stdout.read().decode(), stderr.read().decode())
 
         except (paramiko.SSHException, EOFError) as exc:
-            LOGGER.debug(f"Failed to execute command on {self.host}: {exc}")
+            LOGGER.error(f"Failed to execute command on {self.host}: {exc}")
             return CommandOutput(command, -1, "", "")
 
     def is_connection_alive(self) -> bool:
-        """Check if the connection is still alive asynchronously."""
-        # use the code below if is_active() returns True
+        """Check if the SSH connection is still alive."""
         if self._connection is None:
             return False
 
@@ -83,5 +100,5 @@ class SSHClient:
             self._connection.exec_command('ls', timeout=1)
             return True
 
-        except Exception:
+        except Exception as e:
             return False