nginx反向代理到主机中的应用程序

我有一个应用程序在5000端口的Docker外运行。我试图通过docker compose在nginx中运行反向代理,但无法与主机的端口5000通信。在docker-compose.yml文件中,我有:

ports:
  - 80:80
  - 443:443
  - 5000:5000

当我尝试运行时,我得到:

ERROR: for nginx  Cannot start service nginx: driver failed programming external connectivity on endpoint nginx (374026a0d34c8b6b789dcd82d6aee6c4684b3201258cfbd3fb18623c4101): Error starting userland proxy: listen tcp 0.0.0.0:5000: bind: address already in use

如果我发表评论 - 5000:5000 我得到:

[error] 6#6: *1 connect() failed (111: Connection refused) while connecting to upstream

如何从Docker nginx容器连接到主机中已经运行的应用程序?

编辑:

我的nginx.conf文件

user www-data;
worker_processes auto;
pid /run/nginx.pid;

events {
    worker_connections 768;
}

http {
    upstream mysite {
        server 0.0.0.0:5000;
    }

    server {
        listen 80;
        server_name localhost;

        location / {
        proxy_pass http://mysite;
        }
    }
}

当我尝试curl localhost时的响应是 502 Bad Gateway .应用程序本身和curl 127.0.0.1:5000在主机上响应良好。

编辑2: 我也试过 solution found here 但我明白了 nginx: [emerg] host not found in upstream "docker" .Docker是我主机的主机名。

编辑3: 我的docker-compose.yml

version: '3'
services:
  simple:
    build: ./simple
    container_name: simple
    ports:
      - 80:80
      - 443:443

我的文件:

FROM nginx
COPY nginx.conf /etc/nginx/nginx.conf

EXPOSE 80 443
CMD ["nginx", "-g", "daemon off;", "-c", "/etc/nginx/nginx.conf"]

编辑:

我正在通过Linux中的“hostname”命令获取计算机主机。