ubuntu - Nginx: How to reverse proxy to another container running Nginx in Docker

Question

I am attempting to create a load balancer for my server. The server runs two webservers: mail.example.com - mailcow and my own webserver - but for now, I just need to get the proxy working for my mail server.

I am following the documentation on creating a reverse proxy for Mailcow. My folder structure looks like this:

proxy
    docker-compose.yml
    nginx
        conf.d
            app.conf
mailcow
    docker-compose.yml
    data
        ...

For the full Mailcow directory layout, view it on GitHub

I have both of these containers running using docker compose up -d in their directories. docker ps gives me this output:

ce46ee53e91a   nginx:mainline-alpine    "/docker-entrypoint.…"   11 seconds ago      Up 9 seconds       127.0.0.1:8080->8080/tcp, 80/tcp, 127.0.0.1:8443->8443/tcp                                                                                                                                                                          mailcowdockerized_nginx-mailcow_1
6da454d90564   nginx:alpine             "/docker-entrypoint.…"   20 minutes ago      Up 20 minutes      0.0.0.0:80->80/tcp, 0.0.0.0:433->433/tcp                                                                                                                                                                                            nginx_proxy

My proxy > nginx > conf.d > app.conf looks like this:

server {
  listen 80;
  listen [::]:80;

  error_log /var/log/nginx/error.log;
  access_log /var/log/nginx/access.log;

  server_name mail.example.co.uk;
  return 301 https://$host$request_uri;
}
server {
  listen 443 ssl http2;
  listen [::]:443 ssl http2;
  server_name mail.example.co.uk;

  error_log /var/log/nginx/error.log;
  access_log /var/log/nginx/access.log;

  ssl_certificate /opt/ssl/cert.pem;
  ssl_certificate_key /opt/ssl/key.pem;
  ssl_session_timeout 1d;
  ssl_session_cache shared:SSL:50m;
  ssl_session_tickets off;

  ssl_protocols TLSv1.2;
  ssl_ciphers HIGH:!aNULL:!MD5:!SHA1:!kRSA;
  ssl_prefer_server_ciphers off;

  location /Microsoft-Server-ActiveSync {
    proxy_pass http://127.0.0.1:8080/Microsoft-Server-ActiveSync;
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_connect_timeout 75;
    proxy_send_timeout 3650;
    proxy_read_timeout 3650;
    proxy_buffers 64 256k;
    client_body_buffer_size 512k;
    client_max_body_size 0;
  }

  location / {
    proxy_pass http://127.0.0.1:8080/;
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    client_max_body_size 0;
  }
}

When I visit my domain, I get the RR_CONNECTION_REFUSED but my http is redirected to https which tells me the proxy_pass returned a dead link.

Refused to connect

If I check the logs on both of the containers, there is no request sent which is confusing me because surely the 301 redirect to https would fire an access log - perhaps my browser is doing the redirect not the server and its simply just not listening correctly.

My proxy nginx log looks like this (after a request):

/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: /etc/nginx/conf.d/default.conf is not a file or does not exist
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Configuration complete; ready for start up

Here's my proxy docker-compose.yml:

version: '3'

services:

    nginx-proxy:
        image: nginx:alpine
        container_name: nginx_proxy
        restart: unless-stopped
        tty: true
        volumes:
            - ./nginx/conf.d/:/etc/nginx/conf.d/
            - /opt/mailcow/data/assets/ssl/:/opt/ssl/
        ports:
            - 80:80
            - 433:433

Can anyone help point me in the right direction?

question from:https://stackoverflow.com/questions/65832877/nginx-how-to-reverse-proxy-to-another-container-running-nginx-in-docker

Answer 1

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