MaxKB/apps/common/utils/tool_code.py

# coding=utf-8
import ast
import base64
import gzip
import json
import os
import socket
import subprocess
import sys
import tempfile
import pwd
import resource
import getpass
import random
import time
import uuid_utils.compat as uuid
from contextlib import contextmanager
from common.utils.logger import maxkb_logger
from django.utils.translation import gettext_lazy as _
from maxkb.const import BASE_DIR, CONFIG
from maxkb.const import PROJECT_DIR
from textwrap import dedent

_enable_sandbox = bool(CONFIG.get('SANDBOX', 0))
_run_user = 'sandbox' if _enable_sandbox else getpass.getuser()
_sandbox_path = CONFIG.get("SANDBOX_HOME", '/opt/maxkb-app/sandbox') if _enable_sandbox else os.path.join(PROJECT_DIR, 'data', 'sandbox')
_process_limit_timeout_seconds = int(CONFIG.get("SANDBOX_PYTHON_PROCESS_LIMIT_TIMEOUT_SECONDS", '3600'))
_process_limit_cpu_cores = min(max(int(CONFIG.get("SANDBOX_PYTHON_PROCESS_LIMIT_CPU_CORES", '1')), 1), len(os.sched_getaffinity(0))) if sys.platform.startswith("linux") else os.cpu_count() # 只支持linux，window和mac不支持
_process_limit_mem_mb = int(CONFIG.get("SANDBOX_PYTHON_PROCESS_LIMIT_MEM_MB", '256'))

class ToolExecutor:

    def __init__(self):
        pass

    @staticmethod
    def init_sandbox_dir():
        if not _enable_sandbox:
            # 不启用sandbox就不初始化目录
            return
        try:
            # 只初始化一次
            fd = os.open(os.path.join(PROJECT_DIR, 'tmp', 'tool_executor_init_dir.lock'),
                         os.O_CREAT | os.O_EXCL | os.O_WRONLY)
            os.close(fd)
        except FileExistsError:
            # 文件已存在 → 已初始化过
            return
        maxkb_logger.info("Init sandbox dir.")
        try:
            os.system("chmod -R g-rwx /dev/shm /dev/mqueue")
            os.system("chmod o-rwx /run/postgresql")
        except Exception as e:
            maxkb_logger.warning(f'Exception: {e}', exc_info=True)
            pass
        if CONFIG.get("SANDBOX_TMP_DIR_ENABLED", '0') == "1":
            os.system("chmod g+rwx /tmp")
        # 初始化sandbox配置文件
        sandbox_lib_path = os.path.dirname(f'{_sandbox_path}/lib/sandbox.so')
        sandbox_conf_file_path = f'{sandbox_lib_path}/.sandbox.conf'
        if os.path.exists(sandbox_conf_file_path):
            os.remove(sandbox_conf_file_path)
        allow_subprocess = CONFIG.get("SANDBOX_PYTHON_ALLOW_SUBPROCESS", '0')
        banned_hosts = CONFIG.get("SANDBOX_PYTHON_BANNED_HOSTS", '').strip()
        if banned_hosts:
            hostname = socket.gethostname()
            local_ip = socket.gethostbyname(hostname)
            banned_hosts = f"{banned_hosts},{hostname},{local_ip}"
        with open(sandbox_conf_file_path, "w") as f:
            f.write(f"SANDBOX_PYTHON_BANNED_HOSTS={banned_hosts}\n")
            f.write(f"SANDBOX_PYTHON_ALLOW_SUBPROCESS={allow_subprocess}\n")
        os.system(f"chmod -R 550 {_sandbox_path}")

    try:
        init_sandbox_dir()
    except Exception as e:
        maxkb_logger.error(f'Exception: {e}', exc_info=True)

    def exec_code(self, code_str, keywords, function_name=None):
        _id = str(uuid.uuid7())
        action_function = f'({function_name !a}, locals_v.get({function_name !a}))' if function_name else 'locals_v.popitem()'
        python_paths = CONFIG.get_sandbox_python_package_paths().split(',')
        set_run_user = f'os.setgid({pwd.getpwnam(_run_user).pw_gid});os.setuid({pwd.getpwnam(_run_user).pw_uid});' if _enable_sandbox else ''
        _exec_code = f"""
try:
    import os, sys, json
    from contextlib import redirect_stdout
    path_to_exclude = ['/opt/py3/lib/python3.11/site-packages', '/opt/maxkb-app/apps']
    sys.path = [p for p in sys.path if p not in path_to_exclude]
    sys.path += {python_paths}
    locals_v={{}}
    keywords={keywords}
    globals_v={{}}
    {set_run_user}
    os.environ.clear()
    with redirect_stdout(open(os.devnull, 'w')):
        exec({dedent(code_str)!a}, globals_v, locals_v)
        f_name, f = {action_function}
        globals_v.update(locals_v)
        exec_result=f(**keywords)
    sys.stdout.write("\\n{_id}:")
    json.dump({{'code':200,'msg':'success','data':exec_result}}, sys.stdout, default=str)
except Exception as e:
    if isinstance(e, MemoryError): e = Exception("Cannot allocate more memory: exceeded the limit of {_process_limit_mem_mb} MB.")
    sys.stdout.write("\\n{_id}:")
    json.dump({{'code':500,'msg':str(e),'data':None}}, sys.stdout, default=str)
sys.stdout.flush()
"""
        maxkb_logger.debug(f"Sandbox execute code: {_exec_code}")
        with tempfile.NamedTemporaryFile(mode='w', suffix='.py', delete=True) as f:
            f.write(_exec_code)
            f.flush()
            with execution_timer(_id):
                subprocess_result = self._exec(f.name)
        if subprocess_result.returncode != 0:
            raise Exception(subprocess_result.stderr or subprocess_result.stdout or "Unknown exception occurred")
        lines = subprocess_result.stdout.splitlines()
        result_line = [line for line in lines if line.startswith(_id)]
        if not result_line:
            maxkb_logger.error("\n".join(lines))
            raise Exception("No result found.")
        result = json.loads(result_line[-1].split(":", 1)[1])
        if result.get('code') == 200:
            return result.get('data')
        raise Exception(result.get('msg') + (f'\n{subprocess_result.stderr}' if subprocess_result.stderr else ''))

    def _generate_mcp_server_code(self, _code, params):
        # 解析代码，提取导入语句和函数定义
        try:
            tree = ast.parse(_code)
        except SyntaxError:
            return _code

        imports = []
        functions = []
        other_code = []

        for node in tree.body:
            if isinstance(node, ast.Import) or isinstance(node, ast.ImportFrom):
                imports.append(ast.unparse(node))
            elif isinstance(node, ast.FunctionDef):
                # 修改函数参数以包含 params 中的默认值
                arg_names = [arg.arg for arg in node.args.args]

                # 为参数添加默认值，确保参数顺序正确
                defaults = []
                num_defaults = 0

                # 从后往前检查哪些参数有默认值
                for i, arg_name in enumerate(arg_names):
                    if arg_name in params:
                        num_defaults = len(arg_names) - i
                        break

                # 为有默认值的参数创建默认值列表
                if num_defaults > 0:
                    for i in range(len(arg_names) - num_defaults, len(arg_names)):
                        arg_name = arg_names[i]
                        if arg_name in params:
                            default_value = params[arg_name]
                            if isinstance(default_value, str):
                                defaults.append(ast.Constant(value=default_value))
                            elif isinstance(default_value, (int, float, bool)):
                                defaults.append(ast.Constant(value=default_value))
                            elif default_value is None:
                                defaults.append(ast.Constant(value=None))
                            else:
                                defaults.append(ast.Constant(value=str(default_value)))
                        else:
                            # 如果某个参数没有默认值，需要添加 None 占位
                            defaults.append(ast.Constant(value=None))

                    node.args.defaults = defaults

                func_code = ast.unparse(node)
                functions.append(f"@mcp.tool()\n{func_code}\n")
            else:
                other_code.append(ast.unparse(node))

        # 构建完整的 MCP 服务器代码
        code_parts = ["from mcp.server.fastmcp import FastMCP"]
        code_parts.extend(imports)
        code_parts.append(f"\nmcp = FastMCP(\"{uuid.uuid7()}\")\n")
        code_parts.extend(other_code)
        code_parts.extend(functions)
        code_parts.append("\nmcp.run(transport=\"stdio\")\n")

        return "\n".join(code_parts)

    def generate_mcp_server_code(self, code_str, params):
        python_paths = CONFIG.get_sandbox_python_package_paths().split(',')
        code = self._generate_mcp_server_code(code_str, params)
        set_run_user = f'os.setgid({pwd.getpwnam(_run_user).pw_gid});os.setuid({pwd.getpwnam(_run_user).pw_uid});' if _enable_sandbox else ''
        return f"""
import os, sys, logging
logging.basicConfig(level=logging.WARNING)
logging.getLogger("mcp").setLevel(logging.ERROR)
logging.getLogger("mcp.server").setLevel(logging.ERROR)
path_to_exclude = ['/opt/py3/lib/python3.11/site-packages', '/opt/maxkb-app/apps']
sys.path = [p for p in sys.path if p not in path_to_exclude]
sys.path += {python_paths}
{set_run_user}
os.environ.clear()
exec({dedent(code)!a})
"""

    def get_tool_mcp_config(self, code, params):
        _code = self.generate_mcp_server_code(code, params)
        maxkb_logger.debug(f"Python code of mcp tool: {_code}")
        compressed_and_base64_encoded_code_str = base64.b64encode(gzip.compress(_code.encode())).decode()
        tool_config = {
            'command': sys.executable,
            'args': [
                '-c',
                f'import base64,gzip; exec(gzip.decompress(base64.b64decode(\'{compressed_and_base64_encoded_code_str}\')).decode())',
            ],
            'cwd': _sandbox_path,
            'env': {
                'LD_PRELOAD': f'{_sandbox_path}/lib/sandbox.so',
            },
            'transport': 'stdio',
        }
        return tool_config

    def _exec(self, execute_file):
        kwargs = {'cwd': BASE_DIR, 'env': {
            'LD_PRELOAD': f'{_sandbox_path}/lib/sandbox.so',
        }}
        try:
            subprocess_result = subprocess.run(
                [sys.executable, execute_file],
                timeout=_process_limit_timeout_seconds,
                text=True,
                capture_output=True,
                **kwargs,
                preexec_fn=(lambda: None if (not _enable_sandbox or not sys.platform.startswith("linux")) else (
                    resource.setrlimit(resource.RLIMIT_AS, (_process_limit_mem_mb * 1024 * 1024,) * 2),
                    os.sched_setaffinity(0, set(random.sample(list(os.sched_getaffinity(0)), _process_limit_cpu_cores)))
                ))
            )
            return subprocess_result
        except subprocess.TimeoutExpired:
            raise Exception(_(f"Process execution timed out after {_process_limit_timeout_seconds} seconds."))

    def validate_mcp_transport(self, code_str):
        servers = json.loads(code_str)
        for server, config in servers.items():
            if config.get('transport') not in ['sse', 'streamable_http']:
                raise Exception(_('Only support transport=sse or transport=streamable_http'))


@contextmanager
def execution_timer(id=""):
    start = time.perf_counter()
    try:
        yield
    finally:
        maxkb_logger.debug(f"Tool execution({id}) takes {time.perf_counter() - start:.6f} seconds.")