ModuleNotFoundError：使用 Flask 的 Gunicorn 中没有名为“python_file”的模块

Question

我正在使用 Ubuntu 编写一个网络服务器以托管在 aws ec2 实例中，稍后我会将其链接到前端以进行 POST 和 GET 申请。我执行了与为此项目部署一个简单的 Python Web 服务器 中所示的相同步骤。问题是，当我尝试使用命令

gunicorn -w 3 objDetection:app

时，出现以下错误：

[2023-04-24 21:50:30 +0000] [4826] [INFO] Starting gunicorn 20.1.0
[2023-04-24 21:50:30 +0000] [4826] [INFO] Listening at: http://127.0.0.1:8000 (4826)
[2023-04-24 21:50:30 +0000] [4826] [INFO] Using worker: sync
[2023-04-24 21:50:30 +0000] [4827] [INFO] Booting worker with pid: 4827
[2023-04-24 21:50:30 +0000] [4827] [ERROR] Exception in worker process
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/gunicorn/arbiter.py", line 589, in spawn_worker
    worker.init_process()
  File "/usr/lib/python3/dist-packages/gunicorn/workers/base.py", line 134, in init_process
    self.load_wsgi()
  File "/usr/lib/python3/dist-packages/gunicorn/workers/base.py", line 146, in load_wsgi
    self.wsgi = self.app.wsgi()
  File "/usr/lib/python3/dist-packages/gunicorn/app/base.py", line 67, in wsgi
    self.callable = self.load()
  File "/usr/lib/python3/dist-packages/gunicorn/app/wsgiapp.py", line 58, in load
    return self.load_wsgiapp()
  File "/usr/lib/python3/dist-packages/gunicorn/app/wsgiapp.py", line 48, in load_wsgiapp
    return util.import_app(self.app_uri)
  File "/usr/lib/python3/dist-packages/gunicorn/util.py", line 384, in import_app
    mod = importlib.import_module(module)
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/home/ubuntu/objDetection/__init__.py", line 1, in <module>
    import object_detection
ModuleNotFoundError: No module named 'object_detection'
[2023-04-24 21:50:30 +0000] [4827] [INFO] Worker exiting (pid: 4827)
[2023-04-24 21:50:30 +0000] [4826] [INFO] Shutting down: Master
[2023-04-24 21:50:30 +0000] [4826] [INFO] Reason: Worker failed to boot.

为了更好地理解问题，这里是我的项目路径：

...
/home
 |
 /ubuntu
   |
   /objDetection --> My project folder, everything is here
     |
     __pycache__     
     __init__.py
     coco.names
     frozen_inference_graph.pb
     index.html
     object_detection.py     --> error
     ssd_mobilenet_v3_large_coco_2020_01_04.pbtxt
     venv   --> Virtual environment, used only to install gunicorn, everything else was installed normally (python3, pip, flask, nginx)

还有我的init.py 文件：

import object_detection         # this seems to be the problem
from flask import Flask, request, send_file, render_template
from flask_cors import CORS

# Define Flask and CORS
app = Flask(__name__)
CORS(app)


@app.route('/')
def webpage():
    return render_template("index.html")


# Endpoint for receiving an image for processing photo
@app.route('/post-photo', methods=['POST'])
def handle_image():
    # Retrieving the POST image formData from frontend
    image = request.files.get('image')

    # Return error if image wasn't on the formData
    if image is None:
        return 'Image not found in form', 400

    # Saving image locally
    image.save('./Images/my-photo.jpg')

    # Processing image
    object_detection.process_image('./Images/my-photo.jpg')

    # Return received image message
    return 'Image received successfully!', 200


# Endpoint for sending the processed photo
@app.route('/get-processed-photo', methods=['GET'])
def send_processed_photo():
    processed_image_path = 'Images/processed-photo.jpg'
    return send_file(processed_image_path, mimetype='image/jpg')


if __name__ == '__main__':
    app.run(debug=True)

据我了解，gunicorn 无法找到或无法识别 object_detection.py 的导入。

好心人能帮我解决这个问题吗，我最近开始开发这个项目，但仍然对nginx、gunicorn一无所知。如果有人有知识并且可以解释它，那么解决这个问题并从中学习会很棒。

我安装了python3、pip、flask和nginx。自从我在其他主题中看到有关 gunicorn 的全局路径后，他们创建了一个虚拟环境来在其中安装 gunicorn。我还尝试使用 wsgi 文件，如如何使用 Gunicorn 和 Nginx 部署 Flask（在 Ubuntu 上），但无处可去。

我期待执行命令

gunicorn -w 3 objDetection:app

没有任何错误并让我的网络服务器运行。

PS：对不起，关于 youtube 链接，这是我第一次提出问题和编码这种东西。

Answer 1

不确定我是否做对了，但据我测试，您似乎没有正确执行

gunicorn

命令。

首先，激活虚拟环境：

$ source venv/bin/activate

然后将文件

__init__.py

重命名为

app.py

，然后运行：

(venv)$ gunicorn -w 3 main:app

而且，如果您只使用

venv

来安装

gunicorn

，那么您可能会遇到其他依赖项（例如

flask

和

flask_cors

）的问题。如果是这种情况，只需安装它们并再次运行

gunicorn

命令。

希望有帮助！