我正在尝试在 CentOS 7 上运行的 Nginx 服务器上运行多个 Nodejs 应用程序。我注意到，当我在某些端口上运行 Nodejs 应用程序时，我在浏览器中收到 502 Bad Gateway 错误，因此我检查了错误日志：
[notice] 12806#0: signal process started
[crit] 12807#0: *13 connect() to 127.0.0.1:7777 failed (13: Permission denied) while connecting to upstream, client: **.**.99.58, server: myapp.com, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:7777/", host: "myapp.com"
[crit] 12807#0: *13 connect() to [::1]:7777 failed (13: Permission denied) while connecting to upstream, client: **.**.99.58, server: myapp.com, request: "GET / HTTP/1.1", upstream: "http://[::1]:7777/", host: "myapp.com"
例如，当我更改应用程序以收听 8008 时，一切正常。我检查了权限，如果进程以 root 身份运行并且一切正常。我也玩了超时但没有结果。任何人都可以帮忙吗？