云端Weaviate实例JSONDecodeError排查：是否与Nginx部署有关？

本地启动的Weaviate实例可正常运行，但连接部署在云端EC2的Weaviate实例时，出现JSONDecodeError错误。云端部署方式为：Docker Compose搭配Nginx容器，同时额外使用一层Nginx作为反向代理，将请求路由至对应容器。

连接代码 #

import weaviate
weaviate.Client(
        url="https://myserver/weaviate",
        auth_client_secret=weaviate.AuthApiKey(
            api_key='myapikey'
        ),
        additional_headers={"X-OpenAI-Api-Key": 'your openai key'},
    )

完整报错栈 #

JSONDecodeError                           Traceback (most recent call last)
File ~/opt/anaconda3/envs/test_2/lib/python3.8/site-packages/requests/models.py:971, in Response.json(self, **kwargs)
    970 try:
--> 971     return complexjson.loads(self.text, **kwargs)
    972 except JSONDecodeError as e:
    973     # Catch JSON-related errors and raise as requests.JSONDecodeError
    974     # This aliases json.JSONDecodeError and simplejson.JSONDecodeError

File ~/opt/anaconda3/envs/test_2/lib/python3.8/json/__init__.py:357, in loads(s, cls, object_hook, parse_float, parse_int, parse_constant, object_pairs_hook, **kw)
    354 if (cls is None and object_hook is None and
    355         parse_int is None and parse_float is None and
    356         parse_constant is None and object_pairs_hook is None and not kw):
--> 357     return _default_decoder.decode(s)
    358 if cls is None:

File ~/opt/anaconda3/envs/test_2/lib/python3.8/json/decoder.py:337, in JSONDecoder.decode(self, s, _w)
    333 """Return the Python representation of ``s`` (a ``str`` instance
    334 containing a JSON document).
    335 
    336 """
--> 337 obj, end = self.raw_decode(s, idx=_w(s, 0).end())
    338 end = _w(s, end).end()

File ~/opt/anaconda3/envs/test_2/lib/python3.8/json/decoder.py:355, in JSONDecoder.raw_decode(self, s, idx)
    354 except StopIteration as err:
--> 355     raise JSONDecodeError("Expecting value", s, err.value) from None
    356 return obj, end

JSONDecodeError: Expecting value: line 1 column 1 (char 0)

During handling of the above exception, another exception occurred:

JSONDecodeError                           Traceback (most recent call last)
Cell In[9], line 2
      1 import weaviate
----> 2 weaviate.Client(
      3         url="https://apacplato.863942082387.aws.bain.dev/weaviate",
      4         auth_client_secret=weaviate.AuthApiKey(
      5             api_key='Results!'
      6         ),
      7     additional_headers={"X-OpenAI-Api-Key": 'your openai key'},
      8     )

File ~/opt/anaconda3/envs/test_2/lib/python3.8/site-packages/weaviate/client.py:150, in Client.__init__(self, url, auth_client_secret, timeout_config, proxies, trust_env, additional_headers, startup_period, embedded_options, additional_config)
    147 url, embedded_db = self.__parse_url_and_embedded_db(url, embedded_options)
    148 config = Config() if additional_config is None else additional_config
--> 150 self._connection = Connection(
    151     url=url,
    152     auth_client_secret=auth_client_secret,
    153     timeout_config=_get_valid_timeout_config(timeout_config),
    154     proxies=proxies,
    155     trust_env=trust_env,
    156     additional_headers=additional_headers,
    157     startup_period=startup_period,
    158     embedded_db=embedded_db,
    159     grcp_port=config.grpc_port_experimental,
    160     connection_config=config.connection_config,
    161 )
    162 self.classification = Classification(self._connection)
    163 self.schema = Schema(self._connection)

File ~/opt/anaconda3/envs/test_2/lib/python3.8/site-packages/weaviate/connect/connection.py:662, in Connection.__init__(self, url, auth_client_secret, timeout_config, proxies, trust_env, additional_headers, startup_period, connection_config, embedded_db, grcp_port)
    637 def __init__(
    638     self,
    639     url: str,
   (...)
    648     grcp_port: Optional[int] = None,
    649 ):
    650     super().__init__(
    651         url,
    652         auth_client_secret,
   (...)
    660         grcp_port,
    661     )
--> 662     self._server_version = self.get_meta()["version"]
    663     if self._server_version < "1.14":
    664         _Warnings.weaviate_server_older_than_1_14(self._server_version)

File ~/opt/anaconda3/envs/test_2/lib/python3.8/site-packages/weaviate/connect/connection.py:694, in Connection.get_meta(self)
    692 response = self.get(path="/meta")
    693 if response.status_code == 200:
--> 694     return response.json()
    695 raise UnexpectedStatusCodeException("Meta endpoint", response)

File ~/opt/anaconda3/envs/test_2/lib/python3.8/site-packages/requests/models.py:975, in Response.json(self, **kwargs)
    971     return complexjson.loads(self.text, **kwargs)
    972 except JSONDecodeError as e:
    973     # Catch JSON-related errors and raise as requests.JSONDecodeError
    974     # This aliases json.JSONDecodeError and simplejson.JSONDecodeError
--> 975     raise RequestsJSONDecodeError(e.msg, e.doc, e.pos)

JSONDecodeError: Expecting value: line 1 column 1 (char 0)

疑问 #

该错误是否与Nginx配置或部署方式有关？错误的具体原因是什么？

这个错误大概率和Nginx的反向代理配置有关，具体原因及排查方向如下：

• 反向代理路径转发错误
  客户端请求URL是https://myserver/weaviate，但Nginx可能未正确将/weaviate后的路径转发到Weaviate容器。比如请求/weaviate/meta时，Nginx没有去掉前缀/weaviate，导致Weaviate收到的是/weaviate/meta而非预期的/meta，此时Weaviate返回404页面（HTML内容）而非JSON，客户端尝试解析HTML就会触发JSONDecodeError。

  检查Nginx配置，确保添加路径重写规则，示例：

  location /weaviate/ {
      proxy_pass http://weaviate_container:8080/;
      proxy_set_header Host $host;
      proxy_set_header X-Real-IP $remote_addr;
  }
  

  注意proxy_pass末尾的斜杠，它会将/weaviate/后的路径直接追加到目标URL后，确保Weaviate收到正确路径。

• Nginx返回非JSON响应
  即使状态码显示200，Nginx可能返回HTML内容（比如默认欢迎页、错误页）而非Weaviate的JSON响应。可以用curl直接访问测试：

  curl -H "Authorization: Bearer myapikey" https://myserver/weaviate/meta
  

  如果返回HTML或空内容，说明Nginx未正确转发请求到Weaviate容器。

• 两层Nginx转发冲突
  额外的一层Nginx可能未正确传递请求头（如Authorization、X-OpenAI-Api-Key），或者路径转发规则在两层代理中出现重复或错误，导致最终到达Weaviate的路径不正确。

• Weaviate容器端口配置问题
  检查Docker Compose中Weaviate的端口映射是否正确，确保容器的8080端口（默认）已正确暴露，且第二层Nginx能访问到Weaviate容器的网络。

总结 #

优先排查Nginx的路径转发配置，确认请求能正确到达Weaviate并返回JSON响应。这个错误的核心是客户端收到的响应不是有效JSON格式，根源通常是反向代理的配置问题。

内容的提问来源于stack exchange，提问作者Anoop Mundachal