Reverse proxy to another machine

Question

Explanation of what I am trying to do:

I have 2 servers on the ip 192.168.1.10 (docker reverse proxy) and 192.168.1.20 (other services). I want 10 to redirect requests to 20 (many of these requests are with SSL).

Example:

user request		answer back		return
example_internal.host.com	→	192.168.1.10	→	https://example_internal.host.com
example_external.host.com	→	192.168.1.20	→	https://example_external.host.com

docker-compose.yaml:

version: '3'

services:
  nginx-proxy:
    image: budry/jwilder-nginx-proxy-arm:0.6.0
    restart: always
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro
      - certs:/etc/nginx/certs:ro
      - confd:/etc/nginx/conf.d
      - vhostd:/etc/nginx/vhost.d
      - html:/usr/share/nginx/html
    labels:
      - com.github.jrcs.letsencrypt_nginx_proxy_companion.nginx_proxy
    environment:
      - DEFAULT_HOST=example_external.host.com
    networks:
      - frontend

  letsencrypt:
    image: jrcs/letsencrypt-nginx-proxy-companion:stable
    restart: always
    volumes:
      - certs:/etc/nginx/certs:rw
      - confd:/etc/nginx/conf.d
      - vhostd:/etc/nginx/vhost.d
      - html:/usr/share/nginx/html
      - /var/run/docker.sock:/var/run/docker.sock:ro
    environment:
      - DEFAULT_EMAIL=example@email.com
    networks:
      - frontend
    depends_on:
      - nginx-proxy

  nginx_internal:
    image: nginx:stable-alpine
    hostname: example_internal.host.com
    restart: always
    expose:
      - "80"
    volumes:
      - /var/www/html:/usr/share/nginx/html:rw
    environment:
      - VIRTUAL_HOST=example_internal.host.com
      - LETSENCRYPT_HOST=example_internal.host.com
      - NGINX_HOST=example_internal.host.com
      - LETSENCRYPT_EMAIL=example@email.com
    depends_on:
      - nginx-proxy
      - letsencrypt
    networks:
      - frontend


  nginx_external:
    hostname: example.host.com
    restart: always
    build:
      context: ./scm-proxy
    expose:
      - "80"
    environment:
      - VIRTUAL_HOST=example_external.host.com
      - LETSENCRYPT_HOST=example_external.host.com
      - LETSENCRYPT_EMAIL=example@email.com
      - ENABLE_NGINX_REMOTEIP=1
    depends_on:
      - nginx-proxy
      - letsencrypt
    networks:
      - frontend

networks:
   frontend:
     driver: bridge

scm-proxy/Dockerfile:

FROM nginx:1.15-alpine
COPY nginx.conf /etc/nginx/nginx.conf

scm-proxy/nginx.conf:

worker_processes 1;

events {
  worker_connections 1024;
}

http {

    sendfile on;
    client_max_body_size 0;
    chunked_transfer_encoding on;

    server {
        listen 80;
        location / {
            proxy_pass        http://localhost:80;
            proxy_redirect    off;
            proxy_set_header  Host              $http_host;   # required for docker client's sake
            proxy_set_header  X-Real-IP         $remote_addr; # pass on real client's IP
            proxy_set_header  X-Forwarded-For   $proxy_add_x_forwarded_for;
            proxy_set_header  X-Forwarded-Host $http_host;
            proxy_set_header  X-Forwarded-Proto $scheme;
        }
    }
}

(In several places I have read that I must put in "/etc/hosts" the resolution of the dns, which would be something like "192.168.1.20 example_external.host.com")

The truth is that this is my first time using this technology and I have not been able to find much information and what I have found has been quite difficult to understand.

Answer 1

This is the configuration that has worked for me:

Comments:

Some details are missing such as the nginx.conf file automatically taking the example_external.host.com in the server_name field, but it will be later.

On the other hand, you have to be careful with DEFAULT_HOST= if it is declared, you may get errors. I recommend commenting on it until it works and then uncommenting it

I recommend using this command: docker-compose up -d --remove-orphans --build

Files:

docker-compose.yaml:

version: '3'

services:
  nginx-proxy:
    image: budry/jwilder-nginx-proxy-arm:0.6.0
    restart: always
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro
      - certs:/etc/nginx/certs:ro
      - confd:/etc/nginx/conf.d
      - vhostd:/etc/nginx/vhost.d
      - html:/usr/share/nginx/html
    labels:
      - com.github.jrcs.letsencrypt_nginx_proxy_companion.nginx_proxy
#    environment:
#      - DEFAULT_HOST=example_internal.host.com
    networks:
      - frontend

  letsencrypt:
    image: jrcs/letsencrypt-nginx-proxy-companion:stable
    restart: always
    volumes:
      - certs:/etc/nginx/certs:rw
      - confd:/etc/nginx/conf.d
      - vhostd:/etc/nginx/vhost.d
      - html:/usr/share/nginx/html
      - /var/run/docker.sock:/var/run/docker.sock:ro
    environment:
      - DEFAULT_EMAIL=example@email.com
    networks:
      - frontend

  nginx_external1:
    container_name: tests
    restart: always
    build:
      context: ./scm-proxy
    expose:
      - "80"
    environment:
      - VIRTUAL_HOST=example_external.host.com
      - LETSENCRYPT_HOST=example_external.host.com
      - LETSENCRYPT_EMAIL=example@email.com
    extra_hosts:
      - "example_external.host.com:192.168.1.20"
    depends_on:
      - nginx-proxy
      - letsencrypt
    networks:
      - frontend

networks:
   frontend:
     driver: bridge

scm-proxy/Dockerfile:

FROM nginx:stable-alpine
COPY nginx.conf /etc/nginx/nginx.conf

scm-proxy/nginx.conf:

events {
  worker_connections 1024;
}

http {
  server {
    listen 80;
    listen [::]:80;
    server_name example_external.host.com;
#
    location / {
#        proxy_pass         http://example.com;
#        proxy_pass         http://192.168.1.20;
        proxy_pass         http://example_external.host.com;
    }
  }
}

A special thanks to @richardsefton for his dedication