Replace debug output with proper logging framework

- Added comprehensive logging system with configurable levels
  - TRACE: Shows raw JSON-RPC I/O with server names
  - DEBUG: Detailed operational logging
  - INFO/WARNING/ERROR: Standard logging levels

- New command line options:
  - --log-level: Set logging level (TRACE/DEBUG/INFO/WARNING/ERROR)
  - --log-file: Log to file instead of stderr

- Improved error handling and timeouts:
  - Initial server discovery timeout reduced to 3 seconds
  - Servers marked as offline for 30 minutes after failure
  - Better error messages with server context

- All debug output now goes to stderr, keeping stdout clean for JSON

Example usage:
  mcp-browser --log-level TRACE tools-list  # See raw I/O
  mcp-browser --debug --log-file debug.log  # Debug to file

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
Claude4Ξlope 2025-06-27 16:24:24 +02:00
parent 4a7d3cdc7f
commit 1bb1d05715
7 changed files with 231 additions and 89 deletions

View File

@ -17,7 +17,7 @@ from .proxy import MCPBrowser
from .config import ConfigLoader
from .default_configs import ConfigManager
from .daemon import MCPBrowserDaemon, MCPBrowserClient, get_socket_path, is_daemon_running
from .utils import debug_print, debug_json
from .logging_config import setup_logging, get_logger
def build_mcp_request(args) -> Dict[str, Any]:
@ -106,9 +106,10 @@ def build_mcp_request(args) -> Dict[str, Any]:
def format_mcp_response(args, request: Dict[str, Any], response: Dict[str, Any]):
"""Format and print MCP response based on command."""
logger = get_logger(__name__)
if args.debug:
debug_json("Request", request)
debug_json("Response", response)
logger.debug(f"Request: {json.dumps(request)}")
logger.debug(f"Response: {json.dumps(response)}")
# Format output based on command
if args.command == "tools-list" and "result" in response:
@ -152,7 +153,7 @@ def format_mcp_response(args, request: Dict[str, Any], response: Dict[str, Any])
elif "error" in response:
print(f"Error: {response['error'].get('message', 'Unknown error')}")
if args.debug:
debug_json("Error details", response["error"])
logger.debug(f"Error details: {json.dumps(response['error'])}")
else:
print(json.dumps(response, indent=2))
@ -543,6 +544,22 @@ async def interactive_mode_with_daemon(socket_path: Path):
def main():
"""Main entry point."""
# Parse args first to check for log configuration
args_parser = argparse.ArgumentParser(add_help=False)
args_parser.add_argument("--debug", action="store_true")
args_parser.add_argument("--log-level")
args_parser.add_argument("--log-file")
early_args, _ = args_parser.parse_known_args()
# Setup logging before anything else
log_file = Path(early_args.log_file) if early_args.log_file else None
setup_logging(
debug=early_args.debug,
log_file=log_file,
log_level=early_args.log_level
)
# Now create the full parser
parser = argparse.ArgumentParser(
description="MCP Browser - Universal Model Context Protocol Interface",
epilog="""
@ -596,6 +613,9 @@ Environment:
help="Test connection to specified server")
parser.add_argument("--debug", action="store_true",
help="Enable debug output")
parser.add_argument("--log-level", choices=["TRACE", "DEBUG", "INFO", "WARNING", "ERROR"],
help="Set logging level")
parser.add_argument("--log-file", help="Log to file instead of stderr")
parser.add_argument("--use-daemon", action="store_true",
help="Automatically use daemon if available")
parser.add_argument("--daemon-start", action="store_true",
@ -671,6 +691,14 @@ Environment:
# Create browser
config_path = Path(args.config) if args.config else None
# Apply log level to config if set
if args.log_level == "TRACE" and config_path is None:
from .config import ConfigLoader
loader = ConfigLoader()
config = loader.load()
# TRACE level shows raw I/O
browser = MCPBrowser(
server_name=args.server,
config_path=config_path,

View File

@ -28,7 +28,7 @@ except ImportError:
return False
from .proxy import MCPBrowser
from .utils import debug_print, debug_json
from .logging_config import get_logger
class MCPBrowserDaemon:
@ -40,6 +40,7 @@ class MCPBrowserDaemon:
self.server: Optional[asyncio.Server] = None
self._running = False
self._clients: set = set()
self.logger = get_logger(__name__)
async def start(self):
"""Start the daemon server."""
@ -69,8 +70,8 @@ class MCPBrowserDaemon:
signal.signal(signal.SIGTERM, self._signal_handler)
signal.signal(signal.SIGINT, self._signal_handler)
debug_print(f"MCP Browser daemon started on {self.socket_path}")
debug_print(f"PID: {os.getpid()}")
self.logger.info(f"MCP Browser daemon started on {self.socket_path}")
self.logger.info(f"PID: {os.getpid()}")
# Initialize browser
await self.browser.initialize()
@ -81,7 +82,7 @@ class MCPBrowserDaemon:
def _signal_handler(self, signum, frame):
"""Handle shutdown signals."""
debug_print(f"\nReceived signal {signum}, shutting down...")
self.logger.info(f"Received signal {signum}, shutting down...")
self._running = False
if self.server:
self.server.close()
@ -90,7 +91,7 @@ class MCPBrowserDaemon:
async def _handle_client(self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter):
"""Handle a client connection."""
client_addr = writer.get_extra_info('peername')
debug_print(f"Client connected: {client_addr}")
self.logger.debug(f"Client connected: {client_addr}")
self._clients.add(writer)
try:
@ -112,12 +113,12 @@ class MCPBrowserDaemon:
except asyncio.CancelledError:
pass
except Exception as e:
debug_print(f"Client error: {e}")
self.logger.error(f"Client error: {e}")
finally:
self._clients.discard(writer)
writer.close()
await writer.wait_closed()
debug_print(f"Client disconnected: {client_addr}")
self.logger.debug(f"Client disconnected: {client_addr}")
async def _process_request(self, line: str, writer: asyncio.StreamWriter):
"""Process a JSON-RPC request from client."""
@ -126,7 +127,7 @@ class MCPBrowserDaemon:
# Add debug output if configured
if self.browser.config and self.browser.config.debug:
debug_json("Daemon received", request)
self.logger.debug(f"Daemon received: {json.dumps(request)}")
# Forward to browser
response = await self.browser.call(request)
@ -137,7 +138,7 @@ class MCPBrowserDaemon:
await writer.drain()
if self.browser.config and self.browser.config.debug:
debug_print(f"Daemon sent: {response_str.strip()}")
self.logger.debug(f"Daemon sent: {response_str.strip()}")
except json.JSONDecodeError as e:
error_response = {

View File

@ -0,0 +1,109 @@
"""
Logging configuration for MCP Browser.
"""
import logging
import sys
from pathlib import Path
from typing import Optional
from datetime import datetime
class ServerNameAdapter(logging.LoggerAdapter):
"""Add server name context to log messages."""
def process(self, msg, kwargs):
server = self.extra.get('server', 'main')
return f"[{server}] {msg}", kwargs
def setup_logging(debug: bool = False, log_file: Optional[Path] = None, log_level: Optional[str] = None):
"""
Configure logging for MCP Browser.
Args:
debug: Enable debug logging
log_file: Optional file to write logs to
log_level: Override log level (DEBUG, INFO, WARNING, ERROR)
"""
# Determine log level
if log_level:
level = getattr(logging, log_level.upper(), logging.INFO)
elif debug:
level = logging.DEBUG
else:
level = logging.INFO
# Create formatter
if level == logging.DEBUG:
# Include timestamp and module for debug
formatter = logging.Formatter(
'%(asctime)s - %(name)s - %(levelname)s - %(message)s',
datefmt='%Y-%m-%d %H:%M:%S'
)
else:
# Simpler format for normal use
formatter = logging.Formatter('%(levelname)s: %(message)s')
# Configure root logger
root_logger = logging.getLogger()
root_logger.setLevel(level)
# Remove existing handlers
root_logger.handlers.clear()
# Console handler (stderr)
console_handler = logging.StreamHandler(sys.stderr)
console_handler.setFormatter(formatter)
root_logger.addHandler(console_handler)
# File handler if requested
if log_file:
file_handler = logging.FileHandler(log_file, mode='a')
file_handler.setFormatter(formatter)
root_logger.addHandler(file_handler)
# Set levels for specific loggers
# Suppress some noisy libraries unless in debug mode
if level > logging.DEBUG:
logging.getLogger('asyncio').setLevel(logging.WARNING)
logging.getLogger('urllib3').setLevel(logging.WARNING)
def get_logger(name: str, server: Optional[str] = None) -> logging.Logger:
"""
Get a logger with optional server context.
Args:
name: Logger name (usually __name__)
server: Optional server name for context
Returns:
Logger or LoggerAdapter with server context
"""
logger = logging.getLogger(name)
if server:
return ServerNameAdapter(logger, {'server': server})
return logger
class RawIOFilter(logging.Filter):
"""Filter to only show raw I/O at TRACE level (5)."""
def filter(self, record):
# Only show raw I/O messages at TRACE level
return record.levelno <= 5 or not record.msg.startswith(('>>> ', '<<< '))
# Add custom TRACE level for raw I/O
TRACE = 5
logging.addLevelName(TRACE, 'TRACE')
def trace(self, message, *args, **kwargs):
if self.isEnabledFor(TRACE):
self._log(TRACE, message, args, **kwargs)
# Add trace method to Logger class
logging.Logger.trace = trace

View File

@ -12,13 +12,14 @@ from pathlib import Path
from .server import MCPServer
from .config import MCPServerConfig
from .logging_config import get_logger
class MultiServerManager:
"""Manages multiple MCP servers."""
def __init__(self, debug: bool = False):
self.debug = debug
def __init__(self, logger=None):
self.logger = logger or get_logger(__name__)
self.servers: Dict[str, MCPServer] = {}
self.builtin_servers = self._get_builtin_servers()
@ -52,15 +53,14 @@ class MultiServerManager:
async def start_builtin_servers(self):
"""Start all built-in servers."""
for name, config in self.builtin_servers.items():
if self.debug:
print(f"Starting built-in server: {name}")
self.logger.info(f"Starting built-in server: {name}")
server = MCPServer(config, debug=self.debug)
await server.start()
self.servers[name] = server
# Initialize each server
server = MCPServer(config, logger=get_logger(__name__, name))
try:
await server.start()
self.servers[name] = server
# Initialize each server
await server.send_request("initialize", {
"protocolVersion": "0.1.0",
"capabilities": {},
@ -69,16 +69,16 @@ class MultiServerManager:
"version": "0.1.0"
}
})
self.logger.info(f"Successfully initialized {name}")
except Exception as e:
if self.debug:
print(f"Failed to initialize {name}: {e}")
self.logger.error(f"Failed to initialize {name}: {e}")
async def add_server(self, name: str, config: MCPServerConfig):
"""Add and start a custom server."""
if name in self.servers:
raise ValueError(f"Server {name} already exists")
server = MCPServer(config, debug=self.debug)
server = MCPServer(config, logger=get_logger(__name__, name))
await server.start()
self.servers[name] = server
@ -113,8 +113,7 @@ class MultiServerManager:
all_tools.extend(tools)
except Exception as e:
if self.debug:
print(f"Failed to get tools from {server_name}: {e}")
self.logger.warning(f"Failed to get tools from {server_name}: {e}")
return all_tools
@ -150,8 +149,7 @@ class MultiServerManager:
async def stop_all(self):
"""Stop all servers."""
for name, server in self.servers.items():
if self.debug:
print(f"Stopping server: {name}")
self.logger.info(f"Stopping server: {name}")
await server.stop()
self.servers.clear()

View File

@ -16,7 +16,7 @@ from .multi_server import MultiServerManager
from .registry import ToolRegistry
from .filter import MessageFilter, VirtualToolHandler
from .buffer import JsonRpcBuffer
from .utils import debug_print, debug_json
from .logging_config import get_logger, TRACE
class MCPBrowser:
@ -50,6 +50,7 @@ class MCPBrowser:
self._initialized = False
self._response_buffer: Dict[Union[str, int], asyncio.Future] = {}
self._next_id = 1
self.logger = get_logger(__name__)
async def __aenter__(self):
"""Async context manager entry."""
@ -77,12 +78,12 @@ class MCPBrowser:
# Create multi-server manager if using built-in servers
if self._enable_builtin_servers:
self.multi_server = MultiServerManager(debug=self.config.debug)
self.multi_server = MultiServerManager(logger=self.logger)
await self.multi_server.start_builtin_servers()
# Create main server if specified
if server_name != "builtin-only":
self.server = MCPServer(server_config, debug=self.config.debug)
self.server = MCPServer(server_config, logger=get_logger(__name__, server_name))
# Set up message handling
self.server.add_message_handler(self._handle_server_message)
# Start server
@ -209,22 +210,21 @@ class MCPBrowser:
}
}
# Debug output
if self.config.debug:
debug_json("MCP Browser sending", jsonrpc_object)
# Log at trace level for raw I/O
raw_request = json.dumps(jsonrpc_object)
self.logger.log(TRACE, f">>> {self._server_name}: {raw_request}")
# Create future for response
future = asyncio.Future()
self._response_buffer[request_id] = future
# Send to server
self.server.send_raw(json.dumps(jsonrpc_object))
self.server.send_raw(raw_request)
# Wait for response
try:
response = await asyncio.wait_for(future, timeout=self.config.timeout)
if self.config.debug:
debug_json("MCP Browser received", response)
self.logger.log(TRACE, f"<<< {self._server_name}: {json.dumps(response)}")
return response
except asyncio.TimeoutError:
del self._response_buffer[request_id]

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@ -14,27 +14,38 @@ from pathlib import Path
from .buffer import JsonRpcBuffer
from .config import MCPServerConfig
from .utils import debug_print, debug_json
from .logging_config import get_logger, TRACE
import logging
class MCPServer:
"""Manages a single MCP server process."""
def __init__(self, config: MCPServerConfig, debug: bool = False):
def __init__(self, config: MCPServerConfig, logger: Optional[logging.Logger] = None):
self.config = config
self.debug = debug
self.logger = logger or get_logger(__name__)
self.process: Optional[subprocess.Popen] = None
self.buffer = JsonRpcBuffer()
self._running = False
self._message_handlers: List[Callable[[dict], None]] = []
self._next_id = 1
self._pending_requests: Dict[Union[str, int], asyncio.Future] = {}
self._last_error_time: Optional[float] = None
self._offline_since: Optional[float] = None
async def start(self):
"""Start the MCP server process."""
if self.process:
return
# Check if server is marked as offline
import time
if self._offline_since:
offline_duration = time.time() - self._offline_since
if offline_duration < 1800: # 30 minutes
self.logger.warning(f"Server has been offline for {offline_duration:.0f}s, skipping start")
raise RuntimeError(f"Server marked as offline since {offline_duration:.0f}s ago")
# Prepare environment
env = os.environ.copy()
env.update({
@ -46,26 +57,31 @@ class MCPServer:
# Build command
cmd = self.config.command + self.config.args
if self.debug:
debug_print(f"Starting MCP server: {' '.join(cmd)}")
self.logger.info(f"Starting MCP server: {' '.join(cmd)}")
# Start process
self.process = subprocess.Popen(
cmd,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE if self.debug else subprocess.DEVNULL,
env=env,
text=True,
bufsize=0 # Unbuffered
)
self._running = True
# Start reading outputs
asyncio.create_task(self._read_stdout())
if self.debug:
try:
# Start process
self.process = subprocess.Popen(
cmd,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
env=env,
text=True,
bufsize=0 # Unbuffered
)
self._running = True
self._offline_since = None # Clear offline state
# Start reading outputs
asyncio.create_task(self._read_stdout())
asyncio.create_task(self._read_stderr())
except Exception as e:
self.logger.error(f"Failed to start server: {e}")
self._mark_offline()
raise
async def stop(self):
"""Stop the MCP server process."""
@ -83,6 +99,12 @@ class MCPServer:
self.process = None
def _mark_offline(self):
"""Mark server as offline."""
import time
self._offline_since = time.time()
self.logger.warning(f"Server marked as offline")
async def send_request(self, method: str, params: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
"""
Send a JSON-RPC request and wait for response.
@ -116,15 +138,18 @@ class MCPServer:
self.process.stdin.write(request_str)
self.process.stdin.flush()
if self.debug:
debug_print(f"Sent: {request_str.strip()}")
self.logger.log(TRACE, f">>> {request_str.strip()}")
# Wait for response with appropriate timeout
timeout = 3.0 if method == "initialize" or method == "tools/list" else 30.0
# Wait for response
try:
response = await asyncio.wait_for(future, timeout=30.0)
response = await asyncio.wait_for(future, timeout=timeout)
return response
except asyncio.TimeoutError:
del self._pending_requests[request_id]
self.logger.error(f"Timeout waiting for response to {method} (timeout={timeout}s)")
self._mark_offline()
raise TimeoutError(f"No response for request {request_id}")
def send_raw(self, message: str):
@ -135,8 +160,7 @@ class MCPServer:
if not message.endswith('\n'):
message += '\n'
if self.debug:
debug_print(f"MCP Server sending: {message.strip()}")
self.logger.log(TRACE, f">>> {message.strip()}")
self.process.stdin.write(message)
self.process.stdin.flush()
@ -158,8 +182,8 @@ class MCPServer:
await self._handle_message(msg)
except Exception as e:
if self.debug:
debug_print(f"Error reading stdout: {e}")
self.logger.error(f"Error reading stdout: {e}")
self._mark_offline()
break
async def _read_stderr(self):
@ -170,15 +194,15 @@ class MCPServer:
if not line:
break
debug_print(f"MCP stderr: {line.strip()}")
if line.strip():
self.logger.warning(f"stderr: {line.strip()}")
except Exception:
break
async def _handle_message(self, message: dict):
"""Handle an incoming JSON-RPC message."""
if self.debug:
debug_json("Received", message)
self.logger.log(TRACE, f"<<< {json.dumps(message)}")
# Check if it's a response to a pending request
msg_id = message.get("id")
@ -195,5 +219,4 @@ class MCPServer:
try:
handler(message)
except Exception as e:
if self.debug:
debug_print(f"Handler error: {e}")
self.logger.error(f"Handler error: {e}")

View File

@ -1,17 +0,0 @@
"""
Utility functions for MCP Browser.
"""
import sys
from typing import Any
def debug_print(message: str):
"""Print debug message to stderr."""
print(message, file=sys.stderr, flush=True)
def debug_json(label: str, data: Any):
"""Print JSON data to stderr for debugging."""
import json
print(f"{label}: {json.dumps(data)}", file=sys.stderr, flush=True)