使用 Uwsgi 来自 Flask App 的 ImportError：使用 Flask 处理多个并行请求

Question

我想使用 uWSGI 提供一个简单的 Flask 应用程序，以便拥有一个具有 4 个进程的简单 uWSGI 部署（并因此响应多个并行请求）。

我创建了包含应用程序的 "simple_app.py" 文件：

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello():
    return "Hello World!"

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

还有一个“uwsgi.ini”配置文件：

[uwsgi]
socket = 0.0.0.0:5000
protocol = http
module = simple_app:app
threads = 1
processes = 4

但是，当我尝试使用终端命令 uwsgi uwsgi.ini 在本地 Macbook 机器上启动服务器时，会引发以下导入错误：

*** Operational MODE: preforking ***
Traceback (most recent call last):
  File "./simple_app.py", line 9, in <module>
    from flask import Flask
  File "/anaconda3/lib/python3.7/site-packages/flask/__init__.py", line 14, in <module>
    from jinja2 import escape
  File "/anaconda3/lib/python3.7/site-packages/jinja2/__init__.py", line 33, in <module>
    from jinja2.environment import Environment, Template
  File "/anaconda3/lib/python3.7/site-packages/jinja2/environment.py", line 15, in <module>
    from jinja2 import nodes
  File "/anaconda3/lib/python3.7/site-packages/jinja2/nodes.py", line 19, in <module>
    from jinja2.utils import Markup
  File "/anaconda3/lib/python3.7/site-packages/jinja2/utils.py", line 16, in <module>
    from jinja2._compat import text_type, string_types, implements_iterator, \
  File "/anaconda3/lib/python3.7/site-packages/jinja2/_compat.py", line 31, in <module>
    import pickle
  File "/anaconda3/lib/python3.7/pickle.py", line 33, in <module>
    from struct import pack, unpack
  File "/anaconda3/lib/python3.7/struct.py", line 13, in <module>
    from _struct import *
ImportError: dlopen(/anaconda3/lib/python3.7/lib-dynload/_struct.cpython-37m-darwin.so, 2): Symbol not found: _PyByteArray_Type
  Referenced from: /anaconda3/lib/python3.7/lib-dynload/_struct.cpython-37m-darwin.so
  Expected in: flat namespace
 in /anaconda3/lib/python3.7/lib-dynload/_struct.cpython-37m-darwin.so
unable to load app 0 (mountpoint='') (callable not found or import error)


   *** no app loaded. going in full dynamic mode ***
   *** uWSGI is running in multiple interpreter mode ***
    spawned uWSGI worker 1 (pid: 53858, cores: 1)
    spawned uWSGI worker 2 (pid: 53859, cores: 1)
    spawned uWSGI worker 3 (pid: 53860, cores: 1)
    spawned uWSGI worker 4 (pid: 53861, cores: 1)

这两个文件都在我系统的同一个文件夹中；如何正确启动应用并接收多个并行请求？

Answer 1

我已尝试重现您的情况，它按预期工作。 这是我的 uwsgi.ini 文件：

[uwsgi]
socket = 192.168.1.219:8888
protocol = http
module = simple_app:app
threads = 1
processes = 4

这里是 simple_app.py 文件：

from flask import Flask
app = Flask(__name__)


@app.route('/')
def hello():
    return "Hello World!"


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

我正在通过uwsgi uwsgi.ini 命令启动我的 uwsgi 服务器。

我认为问题不在于 uwsgi 或您的应用程序代码，而在于 Python 或 Flask/Jinja 安装。确保在 anaconda 环境中正确安装了 Flask 和 Jinja。您可以尝试在主机上从头开始安装 Python，或尝试使用 Docker 和任何其他虚拟环境来隔离 Python 安装和安装在其上的模块。