Snow Sight运行Python脚本调用外部API报连接失败错误求助

问题概述 #

在Snow Sight网页UI中运行连接外部API的Snowpark Python脚本时，出现Failed to establish a new connection错误。本地环境不依赖Snowpark时脚本可正常运行，但在Snowflake环境中无法解析域名，无法建立连接。

示例代码 #

import snowflake.snowpark as snowpark
from snowflake.snowpark.functions import col
import requests

def main(session: snowpark.Session): 
  url = "https://www.google.com/"
  res = requests.get(url)
  print(res)

  # Print a sample of the dataframe to standard output.
  # dataframe.show()

  # Return value will appear in the Results tab.
  return main

错误日志 #

Traceback (most recent call last):
File "urllib3/connection.py", line 174, in _new_conn
conn = connection.create_connection(
File "urllib3/util/connection.py", line 72, in create_connection
for res in socket.getaddrinfo(host, port, family, socket.SOCK_STREAM):
File "/usr/lib/python_udf/2ea5e02f17b08cc4ded0dc3a5c4124fe51cdcb5d9c141c6fcf0ec8e525830082/lib/python3.8/socket.py", line 918, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -3] Temporary failure in name resolution
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "urllib3/connectionpool.py", line 714, in urlopen
httplib_response = self._make_request(
File "urllib3/connectionpool.py", line 403, in _make_request
self._validate_conn(conn)
File "urllib3/connectionpool.py", line 1053, in _validate_conn
conn.connect()
File "urllib3/connection.py", line 363, in connect
self.sock = conn = self._new_conn()
File "urllib3/connection.py", line 186, in _new_conn
raise NewConnectionError(
urllib3.exceptions.NewConnectionError: <urllib3.connection.HTTPSConnection object at 0xffff4c666580>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "requests/adapters.py", line 487, in send
resp = conn.urlopen(
File "urllib3/connectionpool.py", line 798, in urlopen
retries = retries.increment(
File "urllib3/util/retry.py", line 592, in increment
raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='www.google.com', port=443): Max retries exceeded with url: / (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0xffff4c666580>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution'))
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
Worksheet, line 8, in main
File "requests/api.py", line 73, in get
return request("get", url, params=params, **kwargs)
File "requests/api.py", line 59, in request
return session.request(method=method, url=url, **kwargs)
File "requests/sessions.py", line 587, in request
resp = self.send(prep, **send_kwargs)
File "requests/sessions.py", line 701, in send
r = adapter.send(request, **kwargs)
File "requests/adapters.py", line 520, in send
raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='www.google.com', port=443): Max retries exceeded with url: / (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0xffff4c666580>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution'))

解决方案 #

1. 配置Snowflake网络访问规则 #

Snowflake默认限制外部网络访问，需通过以下步骤开启：

• 进入Snowflake控制台，找到Account > Networking > Network Policies
• 创建或修改现有网络策略，添加允许访问的外部域名（如www.google.com）或IP范围
• 将该网络策略应用到对应的用户、角色或账户

2. 使用Snowflake外部访问集成（官方推荐） #

这是Snowflake官方指定的外部API访问方式，步骤如下：

1. 创建网络规则，指定允许访问的外部端点：

CREATE OR REPLACE NETWORK RULE my_network_rule
MODE = EGRESS
TYPE = HOST_PORT
VALUE_LIST = ('www.google.com:443');

2. 创建外部访问集成对象：

CREATE OR REPLACE EXTERNAL ACCESS INTEGRATION my_external_access_integration
ALLOWED_NETWORK_RULES = (my_network_rule)
ENABLED = TRUE;

3. 绑定到脚本/存储过程：
   创建存储过程时指定集成，或在Worksheet中通过会话配置调用。示例存储过程创建语句：

CREATE OR REPLACE PROCEDURE call_external_api()
RETURNS VARCHAR
LANGUAGE PYTHON
RUNTIME_VERSION = 3.8
PACKAGES = ('snowflake-snowpark-python', 'requests')
EXTERNAL_ACCESS_INTEGRATIONS = (my_external_access_integration)
HANDLER = 'main';

3. 测试DNS解析 #

如果网络策略已配置仍报错，用Snowflake内置函数测试域名解析：

SELECT SYSTEM$NETWORK_DNS_LOOKUP('www.google.com');

若返回空或错误，联系Snowflake支持调整DNS配置。

4. 配置代理（环境需要时） #

如果Snowflake环境需通过代理访问外部网络，在脚本中添加代理配置：

proxies = {
  'http': 'http://your-proxy:port',
  'https': 'https://your-proxy:port',
}
res = requests.get(url, proxies=proxies)

同时确保代理地址已被Snowflake网络策略允许。

内容的提问来源于stack exchange，提问作者Rutvij Dave