Python requests调用API遇gaierror及无输出问题求助

问题背景 #

• 使用Python的requests库向服务器发送携带文件的POST请求，最初遇到socket.gaierror: [Errno 11001] getaddrinfo failed错误，无法建立连接
• 修改代码添加代理并禁用InsecureRequestWarning后，程序运行无任何输出，无法获取响应状态码，需要排查原因
• 同时咨询：通用的错误调试方法是否以谷歌搜索为主？

初始代码 #

import requests

headers = {
    'authorization': <token>,
}

files = {
    'source': open('ilo5.zip', 'rb'),
    'metadata': open('metadata.json', 'rb'),
}

response = requests.post('https://<blablah>:443/stross/initiateScan', headers=headers, files=files, verify=False)
print("hi")

初始错误信息 #

Traceback (most recent call last):
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\urllib3\connection.py", line 174, in _new_conn        
    conn = connection.create_connection(
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\urllib3\util\connection.py", line 72, in create_connection
    for res in socket.getaddrinfo(host, port, family, socket.SOCK_STREAM):
  File "C:\Program Files\Python310\lib\socket.py", line 955, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno 11001] getaddrinfo failed

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\urllib3\connectionpool.py", line 703, in urlopen      
    httplib_response = self._make_request(
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\urllib3\connectionpool.py", line 386, in _make_request    self._validate_conn(conn)
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\urllib3\connectionpool.py", line 1042, in _validate_conn
    conn.connect()
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\urllib3\connection.py", line 358, in connect
    self.sock = conn = self._new_conn()
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\urllib3\connection.py", line 186, in _new_conn
    raise NewConnectionError(
urllib3.exceptions.NewConnectionError: <urllib3.connection.HTTPSConnection object at 0x0000022FD119A350>: Failed to establish a new connection: [Errno 11001] getaddrinfo failed

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\requests\adapters.py", line 489, in send
    resp = conn.urlopen(
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\urllib3\connectionpool.py", line 787, in urlopen      
    retries = retries.increment(
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\urllib3\util\retry.py", line 592, in increment        
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='<blablah>', port=443): Max retries exceeded with url: /stross/initiateScan (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x0000022FD119A350>: Failed to establish a new connection: [Errno 11001] getaddrinfo failed'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\Users\bose\Desktop\stross\stross-api-call.py", line 12, in <module>
    response = requests.post('<blablah>:443/stross/initiateScan', headers=headers, files=files, verify=False)
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\requests\api.py", line 115, in post
    return request("post", url, data=data, json=json, **kwargs)
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\requests\api.py", line 59, in request
    return session.request(method=method, url=url, **kwargs)
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\requests\sessions.py", line 587, in request
    resp = self.send(prep, **send_kwargs)
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\requests\sessions.py", line 701, in send
    r = adapter.send(request, **kwargs)
  File "C:\Users\bose\AppData\Roaming\Python\Python310\site-packages\requests\adapters.py", line 565, in send
    raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='<blablah>', port=443): Max retries exceeded with url: /stross/initiateScan (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x0000022FD119A350>: Failed to establish a new connection: [Errno 11001] getaddrinfo failed'))

修改后的代码 #

import requests
import urllib3

urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

proxies = {
   'http': 'http://<>.net:8080',
   'https': 'http://<>.net:8080',
}

headers = {
    'authorization': <token>,
}

files = {
    'source': open('ilo5.zip', 'rb'),
    'metadata': open('metadata.json', 'rb'),
}
response = requests.post('https://<>.net:443/stross/initiateScan', headers=headers, 
files=files, verify=False, proxies=proxies)
print("hi. Response Status Code:",response.status_code)

排查步骤与解决方案 #

初始socket.gaierror错误分析 #

这个错误是DNS解析失败，核心是无法将<blablah>域名转化为对应的IP地址，可能原因：

• 域名拼写错误，检查目标地址是否正确
• 本地DNS配置异常，无法解析目标域名，可尝试更换DNS服务器（比如用8.8.8.8）
• 目标域名仅在内网环境可访问，而你的机器不在对应网络中

修改后无输出问题排查 #

程序无输出，说明requests.post()调用没有完成，一直处于等待状态，常见原因及解决方法：

• 代理配置错误：检查代理地址是否正确，确认代理是否允许访问目标服务器；如果代理需要认证，要在URL中加入用户名和密码，格式为http://username:password@proxy.net:8080
• 未设置超时时间：requests默认无超时限制，会一直等待响应。添加timeout参数（例如timeout=30），超时后会抛出异常，便于定位问题
• 文件读取异常：确保ilo5.zip和metadata.json文件存在，路径正确（建议用绝对路径）；同时改用with语句管理文件，避免资源泄漏，示例：

  with open('ilo5.zip', 'rb') as f1, open('metadata.json', 'rb') as f2:
      files = {'source': f1, 'metadata': f2}
      response = requests.post(...)
  

• 网络连通性问题：代理到目标服务器的网络不通，或者服务器拒绝了代理请求，可以用curl命令测试请求是否可行：

  curl -X POST -H "authorization: <token>" -F "source=@ilo5.zip" -F "metadata=@metadata.json" -x http://<>.net:8080 -k https://<>.net:443/stross/initiateScan
  

通用调试建议 #

• 测试代理可用性：先发送简单请求测试代理是否能正常工作，比如：

  test_response = requests.get('https://www.example.com', proxies=proxies, verify=False, timeout=10)
  print(test_response.status_code)
  

• 开启调试日志：打印请求过程的详细信息，帮助定位问题：

  import logging
  import http.client
  http.client.HTTPConnection.debuglevel = 1
  logging.basicConfig()
  logging.getLogger().setLevel(logging.DEBUG)
  requests_log = logging.getLogger("requests.packages.urllib3")
  requests_log.setLevel(logging.DEBUG)
  requests_log.propagate = True
  

• 拆分测试步骤：先测试网络连通性，再测试不带文件的POST请求，最后添加文件参数，逐步排查

关于通用错误调试方法 #

谷歌搜索是常用手段，但不是唯一方式，更高效的调试流程包括：

1. 查看错误栈：错误信息会明确指出问题发生的位置和原因，比如初始错误直接指向DNS解析失败
2. 查阅官方文档：requests库的官方文档有详细的错误处理、参数说明，能快速找到对应问题的解决方案
3. 分步测试验证：把复杂请求拆分成多个简单步骤，逐个验证每个环节是否正常
4. 查看调试日志：开启日志能获取请求、响应的详细过程，发现隐藏的问题

内容的提问来源于stack exchange，提问作者Devadrita Bose