云函数环境下如何修改webdriver_manager的自定义缓存路径

在云函数中搭建无头网页爬虫，使用Selenium结合Webdriver Manager自动化管理驱动，尝试修改缓存路径时触发报错，代码及错误日志如下：

代码示例 #

import os
import logging
# selenium 4
os.environ['GH_TOKEN'] = "gkjkjhjkhjhkjhuihjhgjhg"
os.environ['WDM_LOG'] = str(logging.NOTSET)
os.environ['WDM_LOCAL'] = '1'
os.environ['WDM_SSL_VERIFY'] = '0'

from selenium import webdriver
from selenium.webdriver.chrome.service import Service as ChromeService
from webdriver_manager.chrome import ChromeDriverManager
from selenium.webdriver.chrome.options import Options

def hello_world(request):
    """Responds to any HTTP request.
    Args:
        request (flask.Request): HTTP request object.
    Returns:
        The response text or any set of values that can be turned into a
        Response object using
        `make_response <http://flask.pocoo.org/docs/1.0/api/#flask.Flask.make_response>`.
    """
    # instance of Options class allows
    # us to configure Headless Chrome
    options = Options()
    print("options")
    options.headless = True
    driver = webdriver.Chrome(service=ChromeService(ChromeDriverManager("2.26", cache_valid_range=1, path = r".\\temp\\Drivers").install()
), options=options)

    print("driver was initiated")
    
      
    # this parameter tells Chrome that
    # it should be run without UI (Headless)
   
      
    # initializing webdriver for Chrome with our options
    # driver = webdriver.Chrome(options=options)
    
    # driver = webdriver.Chrome(ChromeDriverManager(path = r"/temp/data").install())      
    
    request_json = request.get_json()
    
    if request_json and 'url' in request_json:
        url = request_json['url']
        driver.get('https://www.geeksforgeeks.org')
        print(driver.title)
        driver.close()
        return f'Success!'
    else:
        return f'Not run'
    

错误日志 #

Traceback (most recent call last): File "/layers/google.python.pip/pip/lib/python3.10/site-packages/flask/app.py", line 2525, in wsgi_app response = self.full_dispatch_request() File "/layers/google.python.pip/pip/lib/python3.10/site-packages/flask/app.py", line 1822, in full_dispatch_request rv = self.handle_user_exception(e) File "/layers/google.python.pip/pip/lib/python3.10/site-packages/flask/app.py", line 1820, in full_dispatch_request rv = self.dispatch_request() File "/layers/google.python.pip/pip/lib/python3.10/site-packages/flask/app.py", line 1796, in dispatch_request return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args) File "/layers/google.python.pip/pip/lib/python3.10/site-packages/functions_framework/__init__.py", line 98, in view_func return function(request._get_current_object()) File "/workspace/main.py", line 28, in hello_world driver = webdriver.Chrome(service=ChromeService(ChromeDriverManager("2.26", cache_valid_range=1, path = r".\\temp\\Drivers").install() File "/layers/google.python.pip/pip/lib/python3.10/site-packages/webdriver_manager/chrome.py", line 39, in install driver_path = self._get_driver_path(self.driver) File "/layers/google.python.pip/pip/lib/python3.10/site-packages/webdriver_manager/core/manager.py", line 31, in _get_driver_path binary_path = self.driver_cache.save_file_to_cache(driver, file) File "/layers/google.python.pip/pip/lib/python3.10/site-packages/webdriver_manager/core/driver_cache.py", line 45, in save_file_to_cache archive = save_file(file, path) File "/layers/google.python.pip/pip/lib/python3.10/site-packages/webdriver_manager/core/utils.py", line 38, in save_file os.makedirs(directory, exist_ok=True) File "/layers/google.python.runtime/python/lib/python3.10/os.py", line 215, in makedirs makedirs(head, exist_ok=exist_ok) File "/layers/google.python.runtime/python/lib/python3.10/os.py", line 215, in makedirs makedirs(head, exist_ok=exist_ok) File "/layers/google.python.runtime/python/lib/python3.10/os.py", line 215, in makedirs makedirs(head, exist_ok=exist_ok)

报错核心原因是Webdriver Manager无法写入指定路径，用户尝试用path = r".\\temp\\Drivers"修改缓存路径但配置错误，需调整路径设置方式。

1. 确认云函数可写路径 #

云函数环境中，当前工作目录（.）通常无写入权限，优先使用系统临时目录（如Linux环境的/tmp），这类目录默认开放写入权限。

2. 正确配置缓存路径的两种方式 #

方式一：通过环境变量全局配置

在导入Webdriver Manager前设置WDM_CACHE_PATH环境变量，全局生效：

import os
# 设置可写的临时目录作为缓存路径
os.environ['WDM_CACHE_PATH'] = "/tmp/wdm_drivers"
# 其他环境变量设置...
from webdriver_manager.chrome import ChromeDriverManager

方式二：通过ChromeDriverManager参数配置

注意：Webdriver Manager的正确参数名是cache_path而非path，修正后的代码如下：

driver = webdriver.Chrome(
    service=ChromeService(
        ChromeDriverManager(
            version="2.26",
            cache_valid_range=1,
            cache_path="/tmp/wdm_drivers"  # 替换为正确参数名
        ).install()
    ),
    options=options
)

3. 额外注意事项 #

• 路径格式：Linux环境下使用正斜杠/作为分隔符，避免Windows风格的反斜杠\\。
• 权限验证：确保指定目录所在路径有写入权限，优先选择系统临时目录。
• 版本兼容：若使用旧版Webdriver Manager，建议升级至最新版以确保cache_path参数可用：

  pip install --upgrade webdriver-manager
  

• 资源释放：使用driver.quit()替代driver.close()，彻底关闭驱动进程，避免资源泄漏。

修改后的完整代码 #

import os
import logging
# selenium 4
os.environ['GH_TOKEN'] = "gkjkjhjkhjhkjhuihjhgjhg"
os.environ['WDM_LOG'] = str(logging.NOTSET)
os.environ['WDM_LOCAL'] = '1'
os.environ['WDM_SSL_VERIFY'] = '0'
# 设置自定义缓存路径到云函数可写的临时目录
os.environ['WDM_CACHE_PATH'] = "/tmp/wdm_drivers"

from selenium import webdriver
from selenium.webdriver.chrome.service import Service as ChromeService
from webdriver_manager.chrome import ChromeDriverManager
from selenium.webdriver.chrome.options import Options

def hello_world(request):
    options = Options()
    options.headless = True
    driver = webdriver.Chrome(
        service=ChromeService(
            ChromeDriverManager(
                version="2.26",
                cache_valid_range=1,
                cache_path="/tmp/wdm_drivers"
            ).install()
        ),
        options=options
    )
    
    print("driver was initiated")
    
    request_json = request.get_json()
    if request_json and 'url' in request_json:
        url = request_json['url']
        driver.get('https://www.geeksforgeeks.org')
        print(driver.title)
        driver.quit()
        return f'Success!'
    else:
        driver.quit()
        return f'Not run'

内容的提问来源于stack exchange，提问作者Gradley bear