NGINX 多个服务器块 - 502 坏网关

Question

我正在尝试使用Nginx和Docker设置多个服务器。现在，我想让它在本地工作，但我会将其导出到网站中使用它。我nginx.conf是：

worker_processes 1;
events { worker_connections 1024; }
http {
client_max_body_size 2048M;
sendfile on;
upstream docker-phpmyadmin {
server phpmyadmin;
}
upstream docker-wordpress {
server wordpress;
}
upstream docker-api {
server api;
}
upstream docker-frontend {
server frontend;
}
server {
listen 80;
server_name example.com;
location / {
proxy_set_header Host $http_host;
proxy_pass http://docker-frontend;
}
}
server {
listen 80;
server_name api.example.com;
location / {
proxy_set_header Host $http_host;
proxy_pass http://docker-api;
}
}
server {
listen 80;
server_name db.example.com;
location / {
proxy_set_header Host $http_host;
proxy_pass http://docker-phpmyadmin;
}
}
server {
listen 80;
server_name admin.example.com;
location / {
proxy_read_timeout 3600;
proxy_set_header Host $http_host;
proxy_pass http://docker-wordpress;
}
}
}

我已将这些条目添加到我的/etc/hosts：

127.0.0.1 example.com
127.0.0.1 db.example.com
127.0.0.1 api.example.com
127.0.0.1 admin.example.com

我的docker-compose.yml包含：

nginx:
build: ./backend/nginx
links:
- wordpress
- phpmyadmin
- frontend
ports: 
- ${NGINX_EXTERNAL_PORT}:80
volumes:
- "./backend/nginx/nginx.conf:/etc/nginx/nginx.conf"

因此，在本地，NGINX_EXTERNAL_PORT设置为 5000。我可以访问db.example.com:5000和admin.example.com:5000，但是当我尝试访问我的主页时example.com:5000我得到：

nginx_1       | 2019/09/18 21:26:52 [error] 6#6: *8 connect() failed (111: Connection refused) while connecting to upstream, client: 172.18.0.1, server: example.com, request: "GET / HTTP/1.1", upstream: "http://172.18.0.7:80/", host: "example.com:5000"
nginx_1       | 172.18.0.1 - - [18/Sep/2019:21:26:52 +0000] "GET / HTTP/1.1" 502 559 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36"

我的服务器块配置中是否缺少某些内容？谢谢！

Answer 1

原来是因为example.com中的应用程序没有公开任何端口，所以在将EXPOSE 3000包含在Dockerfile并将上游更改为

upstream docker-frontend{
server frontend:3000;
}

工程！