[BUG] [Python] Server port remains 8080 regardless of value in spec

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

The server port generated by the python-flask generator remains 8080 in __main__.py, regardless of the values used in the spec yaml file. According to the mustache template, the server port should be replaced, though?

openapi-generator version

OpenAPI generator 4.3.1 installed with Homebrew

OpenAPI declaration file content or url

Spec snippet:

openapi: 3.0.3

servers:
  - url: 'http://localhost:8082'
info:
  version: 0.0.1
  title: Test API
 
paths:
  /resources:
    get:
      summary: List resources
      responses:
        '200':
          description: OK

I also tried with server variables

openapi: 3.0.3

servers:
  - url: 'http://localhost:{port}'
    variables:
      port:
        default: '8082'
info:
  version: 0.0.1
  title: Test API
 
paths:
  /resources:
    get:
      summary: List resources
      responses:
        '200':
          description: OK

Generation Details

Without server variables:

openapi-generator generate -i spec.yaml -o python-server -g python-flask

With server variables:

openapi-generator generate -i spec.yaml -o python-server -g python-flask --server-variables port=8082

The code __main__.py generated has 8080 as the application port:

#!/usr/bin/env python3

import connexion

from openapi_server import encoder


def main():
    app = connexion.App(__name__, specification_dir='./openapi/')
    app.app.json_encoder = encoder.JSONEncoder
    app.add_api('openapi.yaml',
                arguments={'title': 'Test API'},
                pythonic_params=True)
    app.run(port=8080)


if __name__ == '__main__':
    main()

I would expect the port to be 8082, as in written in the spec

Steps to reproduce

Use the spec and generation command above to generate the python server stubs.

Related issues/PRs

Suggest a fix

Start with the python-flask main.mustache template referenced in the issue and compare it with the generated main.py output from the provided spec and generation command. Confirm that the generated server uses the 8082 value from the OpenAPI server definition or server variable instead of the hard-coded 8080, and check both reproduction commands.