獨角獸 x Nginx x AWS，解決 *11 connect() to unix:/home/ec2-user/app/current/tmp/sockets/unicorn.sock failed (13: Permission denied) while connecting to upstream 的錯誤方法

当我试图通过浏览器经由Nginx连接到Unicorn时，收到502 Bad Gateway错误响应，我对此进行了调查。

nginx的错误日志

*11 connect() to unix:/home/ec2-user/app/current/tmp/sockets/unicorn.sock failed (13: Permission denied) while connecting to upstream

非常抱歉，根据提示发现没有权限，查找了正在运行nginx的用户。

[ec2-user@ip-xxx.xxxx.xxx.xxx]$ ps aux | grep nginx
root      2089  0.0  0.0 109476  2124 ?        Ss   02:05   0:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
nginx 2091  0.0  0.0 109888  3248 ?        S    02:05   0:00 nginx: worker process

看起来默认情况下会变成nginx这样。
如果修改以下配置文件并将执行用户更改为ec2-user（或应用程序的执行用户），问题就可以解决了。

# For more information on configuration, see:
#   * Official English Documentation: http://nginx.org/en/docs/
#   * Official Russian Documentation: http://nginx.org/ru/docs/

#user  nginx;
user  ec2-user;
worker_processes  1;