Files
mc-webui/meshcore-bridge/bridge.py

519 lines
17 KiB
Python

"""
MeshCore Bridge - HTTP API wrapper for meshcli subprocess calls
This service runs as a separate container with exclusive USB device access.
The main mc-webui container communicates with this bridge via HTTP.
Architecture:
- Maintains a persistent meshcli session (subprocess.Popen)
- Multiplexes: JSON adverts -> .jsonl log, CLI commands -> HTTP responses
- Thread-safe command queue with event-based synchronization
"""
import os
import subprocess
import logging
import threading
import time
import json
import queue
import uuid
from pathlib import Path
from flask import Flask, request, jsonify
logging.basicConfig(
level=logging.INFO,
format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
logger = logging.getLogger(__name__)
app = Flask(__name__)
# Configuration
MC_SERIAL_PORT = os.getenv('MC_SERIAL_PORT', '/dev/ttyUSB0')
MC_CONFIG_DIR = os.getenv('MC_CONFIG_DIR', '/config')
MC_DEVICE_NAME = os.getenv('MC_DEVICE_NAME', 'meshtastic')
DEFAULT_TIMEOUT = 10
RECV_TIMEOUT = 60
class MeshCLISession:
"""
Manages a persistent meshcli subprocess session.
Features:
- Single long-lived meshcli process with stdin/stdout pipes
- Multiplexing: JSON adverts logged to .jsonl, CLI commands return responses
- Thread-safe command queue with event-based synchronization
- Auto-restart watchdog for crashed meshcli processes
"""
def __init__(self, serial_port, config_dir, device_name):
self.serial_port = serial_port
self.config_dir = Path(config_dir)
self.device_name = device_name
# Ensure config directory exists
self.config_dir.mkdir(parents=True, exist_ok=True)
self.advert_log_path = self.config_dir / f"{device_name}.adverts.jsonl"
# Process handle
self.process = None
self.process_lock = threading.Lock()
# Command queue: (cmd_id, command_string, event, response_dict)
self.command_queue = queue.Queue()
# Pending commands: cmd_id -> {"event": Event, "response": [], "done": False, "error": None}
self.pending_commands = {}
self.pending_lock = threading.Lock()
self.current_cmd_id = None
# Threads
self.stdout_thread = None
self.stderr_thread = None
self.stdin_thread = None
self.watchdog_thread = None
# Shutdown flag
self.shutdown_flag = threading.Event()
# Start session
self._start_session()
def _start_session(self):
"""Start meshcli process and worker threads"""
logger.info(f"Starting meshcli session on {self.serial_port}")
try:
self.process = subprocess.Popen(
['meshcli', '-s', self.serial_port],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
text=True,
bufsize=1 # Line-buffered
)
logger.info(f"meshcli process started (PID: {self.process.pid})")
# Start worker threads
self.stdout_thread = threading.Thread(target=self._read_stdout, daemon=True, name="stdout-reader")
self.stdout_thread.start()
self.stderr_thread = threading.Thread(target=self._read_stderr, daemon=True, name="stderr-reader")
self.stderr_thread.start()
self.stdin_thread = threading.Thread(target=self._send_commands, daemon=True, name="stdin-writer")
self.stdin_thread.start()
self.watchdog_thread = threading.Thread(target=self._watchdog, daemon=True, name="watchdog")
self.watchdog_thread.start()
# Initialize session settings
time.sleep(0.5) # Let meshcli initialize
self._init_session_settings()
logger.info("meshcli session fully initialized")
except Exception as e:
logger.error(f"Failed to start meshcli session: {e}")
raise
def _init_session_settings(self):
"""Configure meshcli session for advert logging and message subscription"""
logger.info("Configuring meshcli session settings")
# Send configuration commands directly to stdin (bypass queue for init)
if self.process and self.process.stdin:
try:
self.process.stdin.write('set json_log_rx on\n')
self.process.stdin.write('set print_adverts on\n')
self.process.stdin.write('msgs_subscribe\n')
self.process.stdin.flush()
logger.info("Session settings applied: json_log_rx=on, print_adverts=on, msgs_subscribe")
except Exception as e:
logger.error(f"Failed to apply session settings: {e}")
def _read_stdout(self):
"""Thread: Read stdout line-by-line, parse adverts vs CLI responses"""
logger.info("stdout reader thread started")
try:
for line in iter(self.process.stdout.readline, ''):
if self.shutdown_flag.is_set():
break
line = line.rstrip('\n\r')
if not line:
continue
# Try to parse as JSON advert
if self._is_advert_json(line):
self._log_advert(line)
continue
# Otherwise, append to current CLI response
self._append_to_current_response(line)
except Exception as e:
logger.error(f"stdout reader error: {e}")
finally:
logger.info("stdout reader thread exiting")
def _read_stderr(self):
"""Thread: Read stderr and log errors"""
logger.info("stderr reader thread started")
try:
for line in iter(self.process.stderr.readline, ''):
if self.shutdown_flag.is_set():
break
line = line.rstrip('\n\r')
if line:
logger.warning(f"meshcli stderr: {line}")
except Exception as e:
logger.error(f"stderr reader error: {e}")
finally:
logger.info("stderr reader thread exiting")
def _send_commands(self):
"""Thread: Send queued commands to stdin and monitor responses"""
logger.info("stdin writer thread started")
try:
while not self.shutdown_flag.is_set():
try:
# Get command from queue (with timeout to check shutdown flag)
cmd_id, command, event, response_dict = self.command_queue.get(timeout=1.0)
except queue.Empty:
continue
logger.info(f"Sending command [{cmd_id}]: {command}")
# Register pending command
with self.pending_lock:
self.pending_commands[cmd_id] = response_dict
self.current_cmd_id = cmd_id
response_dict["last_line_time"] = time.time()
try:
# Send command
self.process.stdin.write(f'{command}\n')
self.process.stdin.flush()
# Start timeout monitor thread
monitor_thread = threading.Thread(
target=self._monitor_response_timeout,
args=(cmd_id, response_dict, event),
daemon=True
)
monitor_thread.start()
except Exception as e:
logger.error(f"Failed to send command [{cmd_id}]: {e}")
with self.pending_lock:
response_dict["error"] = str(e)
response_dict["done"] = True
event.set()
except Exception as e:
logger.error(f"stdin writer error: {e}")
finally:
logger.info("stdin writer thread exiting")
def _monitor_response_timeout(self, cmd_id, response_dict, event, timeout_ms=300):
"""Monitor if response has finished (no new lines for timeout_ms)"""
try:
while not self.shutdown_flag.is_set():
time.sleep(timeout_ms / 1000.0)
with self.pending_lock:
# Check if command still pending
if cmd_id not in self.pending_commands:
return # Already completed
# Check if we got new lines recently
time_since_last_line = time.time() - response_dict.get("last_line_time", 0)
if time_since_last_line >= (timeout_ms / 1000.0):
# No new lines for timeout period - mark as done
logger.info(f"Command [{cmd_id}] completed (timeout-based)")
response_dict["done"] = True
event.set()
if self.current_cmd_id == cmd_id:
self.current_cmd_id = None
return
except Exception as e:
logger.error(f"Monitor thread error for [{cmd_id}]: {e}")
def _watchdog(self):
"""Thread: Monitor process health and restart if crashed"""
logger.info("watchdog thread started")
while not self.shutdown_flag.is_set():
time.sleep(5)
if self.process and self.process.poll() is not None:
logger.error(f"meshcli process died (exit code: {self.process.returncode})")
logger.info("Attempting to restart meshcli session...")
# Cancel all pending commands
with self.pending_lock:
for cmd_id, resp_dict in self.pending_commands.items():
resp_dict["error"] = "meshcli process crashed"
resp_dict["done"] = True
resp_dict["event"].set()
self.pending_commands.clear()
# Restart
try:
self._start_session()
except Exception as e:
logger.error(f"Failed to restart session: {e}")
time.sleep(10) # Wait before retry
logger.info("watchdog thread exiting")
def _is_advert_json(self, line):
"""Check if line is a JSON advert"""
try:
data = json.loads(line)
return isinstance(data, dict) and data.get("payload_typename") == "ADVERT"
except (json.JSONDecodeError, ValueError):
return False
def _log_advert(self, json_line):
"""Log advert JSON to .jsonl file with timestamp"""
try:
data = json.loads(json_line)
data["ts"] = time.time()
with open(self.advert_log_path, 'a', encoding='utf-8') as f:
f.write(json.dumps(data, ensure_ascii=False) + '\n')
logger.debug(f"Logged advert from {data.get('from_id', 'unknown')}")
except Exception as e:
logger.error(f"Failed to log advert: {e}")
def _append_to_current_response(self, line):
"""Append line to current CLI command response and update timestamp"""
with self.pending_lock:
if not self.current_cmd_id:
# No active command, probably init output - log and ignore
logger.debug(f"Unassociated output: {line}")
return
cmd_id = self.current_cmd_id
# Append to response buffer
self.pending_commands[cmd_id]["response"].append(line)
# Update timestamp of last received line
self.pending_commands[cmd_id]["last_line_time"] = time.time()
def execute_command(self, args, timeout=DEFAULT_TIMEOUT):
"""
Execute a CLI command via the persistent session.
Args:
args: List of command arguments (e.g., ['recv', '--timeout', '60'])
timeout: Max time to wait for response
Returns:
Dict with success, stdout, stderr, returncode
"""
cmd_id = str(uuid.uuid4())[:8]
# Build command line - use double quotes for args with spaces/special chars
# meshcli doesn't parse like shell, so we need simple double-quote wrapping
quoted_args = []
for arg in args:
# If argument contains spaces or special chars, wrap in double quotes
if ' ' in arg or '"' in arg or "'" in arg:
# Escape internal double quotes
escaped = arg.replace('"', '\\"')
quoted_args.append(f'"{escaped}"')
else:
quoted_args.append(arg)
command = ' '.join(quoted_args)
event = threading.Event()
response_dict = {
"event": event,
"response": [],
"done": False,
"error": None,
"last_line_time": time.time()
}
# Queue command
self.command_queue.put((cmd_id, command, event, response_dict))
logger.info(f"Command [{cmd_id}] queued: {command}")
# Wait for completion
if not event.wait(timeout):
logger.error(f"Command [{cmd_id}] timeout after {timeout}s")
# Cleanup
with self.pending_lock:
if cmd_id in self.pending_commands:
del self.pending_commands[cmd_id]
return {
'success': False,
'stdout': '',
'stderr': f'Command timeout after {timeout} seconds',
'returncode': -1
}
# Retrieve response
with self.pending_lock:
resp = self.pending_commands.pop(cmd_id, None)
if not resp:
return {
'success': False,
'stdout': '',
'stderr': 'Command response lost',
'returncode': -1
}
if resp["error"]:
return {
'success': False,
'stdout': '',
'stderr': resp["error"],
'returncode': -1
}
return {
'success': True,
'stdout': '\n'.join(resp["response"]),
'stderr': '',
'returncode': 0
}
def shutdown(self):
"""Gracefully shutdown session"""
logger.info("Shutting down meshcli session")
self.shutdown_flag.set()
if self.process:
try:
self.process.terminate()
self.process.wait(timeout=5)
except:
self.process.kill()
logger.info("Session shutdown complete")
# Global session instance
meshcli_session = None
@app.route('/health', methods=['GET'])
def health():
"""Health check endpoint"""
session_status = "healthy" if meshcli_session and meshcli_session.process and meshcli_session.process.poll() is None else "unhealthy"
return jsonify({
'status': session_status,
'serial_port': MC_SERIAL_PORT,
'advert_log': str(meshcli_session.advert_log_path) if meshcli_session else None
}), 200
@app.route('/cli', methods=['POST'])
def execute_cli():
"""
Execute meshcli command via persistent session.
Request JSON:
{
"args": ["recv"],
"timeout": 60 (optional)
}
Response JSON:
{
"success": true,
"stdout": "...",
"stderr": "...",
"returncode": 0
}
"""
try:
data = request.get_json()
if not data or 'args' not in data:
return jsonify({
'success': False,
'stdout': '',
'stderr': 'Missing required field: args',
'returncode': -1
}), 400
args = data['args']
timeout = data.get('timeout', DEFAULT_TIMEOUT)
# Special handling for recv command (longer timeout)
if args and args[0] == 'recv':
timeout = data.get('timeout', RECV_TIMEOUT)
if not isinstance(args, list):
return jsonify({
'success': False,
'stdout': '',
'stderr': 'args must be a list',
'returncode': -1
}), 400
# Check session health
if not meshcli_session or not meshcli_session.process:
return jsonify({
'success': False,
'stdout': '',
'stderr': 'meshcli session not initialized',
'returncode': -1
}), 503
# Execute via persistent session
result = meshcli_session.execute_command(args, timeout)
return jsonify(result), 200
except Exception as e:
logger.error(f"API error: {e}")
return jsonify({
'success': False,
'stdout': '',
'stderr': str(e),
'returncode': -1
}), 500
if __name__ == '__main__':
logger.info(f"Starting MeshCore Bridge on port 5001")
logger.info(f"Serial port: {MC_SERIAL_PORT}")
logger.info(f"Config dir: {MC_CONFIG_DIR}")
logger.info(f"Device name: {MC_DEVICE_NAME}")
# Initialize persistent meshcli session
try:
meshcli_session = MeshCLISession(
serial_port=MC_SERIAL_PORT,
config_dir=MC_CONFIG_DIR,
device_name=MC_DEVICE_NAME
)
logger.info(f"Advert logging to: {meshcli_session.advert_log_path}")
except Exception as e:
logger.error(f"Failed to initialize meshcli session: {e}")
logger.error("Bridge will start but /cli endpoint will be unavailable")
# Run on all interfaces to allow Docker network access
app.run(host='0.0.0.0', port=5001, debug=False)