使用Python Connexion开发REST服务时遇参数缺失错误排查

错误栈信息 #

Traceback (most recent call last):
 File "/opt/homebrew/lib/python3.9/site-packages/flask/app.py", line 2548, in __call__
   return self.wsgi_app(environ, start_response)
 File "/opt/homebrew/lib/python3.9/site-packages/flask/app.py", line 2528, in wsgi_app
   response = self.handle_exception(e)
 File "/opt/homebrew/lib/python3.9/site-packages/flask/app.py", line 2525, in wsgi_app
   response = self.full_dispatch_request()
 File "/opt/homebrew/lib/python3.9/site-packages/flask/app.py", line 1822, in full_dispatch_request
   rv = self.handle_user_exception(e)
 File "/opt/homebrew/lib/python3.9/site-packages/flask/app.py", line 1820, in full_dispatch_request
   rv = self.dispatch_request()
 File "/opt/homebrew/lib/python3.9/site-packages/flask/app.py", line 1796, in dispatch_request
   return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
 File "/opt/homebrew/lib/python3.9/site-packages/connexion/decorators/decorator.py", line 68, in wrapper
   response = function(request)
 File "/opt/homebrew/lib/python3.9/site-packages/connexion/decorators/uri_parsing.py", line 149, in wrapper
   response = function(request)
 File "/opt/homebrew/lib/python3.9/site-packages/connexion/decorators/validation.py", line 196, in wrapper
   response = function(request)
 File "/opt/homebrew/lib/python3.9/site-packages/connexion/decorators/produces.py", line 41, in wrapper
   response = function(request)
 File "/opt/homebrew/lib/python3.9/site-packages/connexion/decorators/parameter.py", line 120, in wrapper
   return function(**kwargs)
TypeError: create() missing 1 required positional argument: 'applicant'

接口调用curl命令 #

curl -X 'POST' \
  'http://localhost:8181/myco/app-orchestrator/1.0.0/applicant' \
  -H 'accept: text/plain' \
  -H 'Content-Type: application/json' \
  -d '{
  "addressLine1": "123 Street",
  "addressLine2": "unit 2309",
  "birthDate": "01/01/2021",
  "city": "San Francisco",
  "emailAddress": "test@test.com",
  "firstName": "Test2",
  "lastName": "Tester2",
  "middleName": "T",
  "phoneNumber": "123-321-4321",
  "ssn": "123456789",
  "state": "CA",
  "zip": "12345-1234"
}'

问题背景与排查方向 #

使用Connexion、Marshmallow和SqlAlchemy开发Python基础REST服务，调用创建applicant的POST接口时出现上述错误。

最初怀疑需要在POST请求中传入自增主键applicantId（字段定义为db.Column(db.Integer, primary_key=True)），但随后认为更可能是Swagger规范配置问题，导致请求体未传递给applicants.create方法。

示例代码已上传至GitHub仓库。

复现步骤 #

• 执行python build_database.py
• 执行python server.py

Swagger UI地址：http://localhost:8181/myco/app-orchestrator/1.0.0/ui

相关Swagger配置片段 #

/applicant:
    post:
      summary: Create applicant
      operationId: applicants.create
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Applicant'
        required: true
      responses:
        '201':
          description: Applicant created
          content:
            text/plain:
              schema:
                type: string
                example: Applicant created
        '400':
          description: invalid request
        '500':
          description: error

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