我正在尝试在ubuntu 20.04服务器上部署flask项目（uwsgi + Nginx）。所以，我选择了Digital Ocean。
我得到**502 bad gateway nginx/1.18.0（Ubuntu）**错误。
在检查nginx错误日志后，我发现

upstream prematurely closed connection while reading response header from upstream, client: 93.37.157.148, server: 3.75.132.146, request: "GET /favicon.ico HTTP/1.1", upstream: "uwsgi://unix:/home/ubuntu/flask-app/webapp/flask-app.sock:", host: "3.75.132.146", referrer: "http://3.75.132.146/"

我的.ini文件包括：

[uwsgi]
module = wsgi:app
wsgi-file = /home/ubuntu/flask-app/webapp/wsgi.py
chdir = /home/ubuntu/flask-app/webapp/
protocol = http
#home = /usr/local/lib/python3.8/dist-packages/

master = true
processes = 5

limit-as = 512
uid = ubuntu
gid = www-data
socket = flask-app.sock

chown-socket = ubuntu
chmod-socket = 777
vacuum = true

die-on-term = true

我的nginx配置文件包括：

server {
    listen 80;
    server_name 3.75.132.146;

    location /static {
        alias /home/ubuntu/flask-app/webapp/static/;
    }
    location / {
        include uwsgi_params;
        uwsgi_pass unix:/home/ubuntu/flask-app/webapp/flask-app.sock;
    }
}

我一直在网上搜索，似乎没有人对此有一个坚实的解决方案。请帮助我，如果有人已经面临这一点和解决这个问题。
谢谢