我按照这个在Ubuntu 16-04上部署了一个 flask应用程序（简单的hello world）。digital Ocean tutorial
在测试uWSGI Serving之前，一切正常。之后，我按照所描述的步骤，当我终于到达底部并检查服务器IP地址时，我得到：

502 Bad Gateway

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好吧，我搜索并检查了我的错误日志，我得到了这个：-

2017/01/16 05:29:27 [crit] 20714#20714: *2 connect() to unix:/home/sajjan/project/project.sock failed (2: No such file or directory) while connecting to upstream, client: xx.9.xxx.xxx, server: 138.xxx.xx.xxx, request: "GET / HTTP/1.1", upstream: "uwsgi://unix:/home/sajjan/project/project.sock:", host: "xx.xx.xx.xx"

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因此，在获取错误日志后，我手动创建了文件project.sock。再次转到服务器ip地址，然后出现同样的错误**“502 Bad Gateway”**
再次检查了错误日志，发现

2017/01/16 06:07:11 [crit] 20874#20874: *1 connect() to unix:/home/sajjan/project/project.sock failed (13: Permission denied) while connecting to upstream, client: 47.9.237.113, server: XX.XX.XX.XX, request: "GET / HTTP/1.1", upstream: "uwsgi://unix:/home/sajjan/project/project.sock:", host: " XX.XX.XX.XX "

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我弄清楚了权限问题，并使用下面的命令更改权限

sudo chmod 666 project.sock

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现在我检查了权限（使用ls -l文件名）

-rw-rw-rw- 1 root root 0 Jan 16 05:31 project.sock

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现在我回去检查服务器的IP，但发现相同的“502 Bad Gateway”。我再次检查错误日志，发现：

017/01/16 06:13:31 [error] 20897#20897: *6 connect() to unix:/home/sajjan/project/project.sock failed (111: Connection refused) while connecting to upstream, client: 47.9.237.113, server: XX.XX.XX.XX, request: "GET /favicon.ico HTTP/1.1", upstream: "uwsgi://unix:/home/sajjan/project/project.sock:", host: " XX.XX.XX.XX ", referrer: "http:// XX.XX.XX.XX /"

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我在谷歌上搜索了上述错误，在过去的两天里读了很多，但似乎没有什么对我有效。我已经检查了这些答案，但没有帮助stackanswer-1stackanswer-2和这些沿着，我检查了所有的数字海洋社区线程，但**似乎没有工作。
我是一个服务器新手，对ubuntu了解不多。如果你能帮助我找出我做错了什么，或者建议一些更好的教程/方法来部署我的flask应用程序，那么我将非常感激。
这些是我的文件

1. hello.py

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "<h1 style='color:blue'>Hello There!</h1>"

if __name__ == "__main__":
    app.run(host='0.0.0.0')

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1. project.ini

[uwsgi]

module = wsgi:app

master = true

processes = 5

socket = /home/sajjan/project/project.sock

chmod-socket = 660

vacuum = true

die-on-term = true

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1. wsgi.py

from hello import app

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

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1.下面是文件：/etc/nginx/sites-available/project

server {
    listen 80;
    server_name 138.197.28.107;

    location / {
        include uwsgi_params;
        uwsgi_pass unix:/home/sajjan/project/project.sock;
    }
}

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当我运行命令时：

sudo service uwsgi restart

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产出：

Failed to restart wsgi.service: Unit wsgi.service not found.

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while输出

sudo service nginx status/restart

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那么这表明nginx正在运行。
帮帮我，如果你还想知道什么，就告诉我。谢啦，谢啦

编辑：

我创建了一个project.service文件，其内容是：

[Unit]
    Description=uWSGI instance to serve project
    After=network.target

    [Service]
    User=sajjan
    Group=www-data
    WorkingDirectory=/home/sajjan/project
    Environment="PATH=/home/sajjan/project/venv/bin"
    ExecStart=/home/sajjan/project/venv/bin/uwsgi --ini project.ini

    [Install]
    WantedBy=multi-user.target

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我发现我必须运行下面的命令：

sudo systemctl start project

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输出为：

Warning: project.service changed on disk. Run 'systemctl daemon-reload' to reload units.

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当我跑步的时候

sudo systemcl reload project

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然后输出：

Failed to reload project.service: Job type reload is not applicable for unit project.service.
    See system logs and 'systemctl status project.service' for details.

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当我检查“systemctl status project.service”

● project.service - uWSGI instance to serve project
      Loaded: loaded (/etc/systemd/system/project.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Mon 2017-01-16 17:49:29 UTC; 6min ago
      Main PID: 27157 (code=exited, status=203/EXEC)

     Jan 16 17:49:29 learningwithpython systemd[1]: Started uWSGI instance to serve project.
     Jan 16 17:49:29 learningwithpython systemd[1]: project.service: Main process exited, code=exited, status=203/EXEC
     Jan 16 17:49:29 learningwithpython systemd[1]: project.service: Unit entered failed state.
     Jan 16 17:49:29 learningwithpython systemd[1]: project.service: Failed with result 'exit-code'.

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