Multiple Nginx servers (api + backend) under docker – Phpmyadmin

I have problems to configure docker with two symfony apps under docker:

• front (symfony)
• backend (symfony)
• nginx

When I use my navigator, i can access to http://dev.front.local and http://dev.backend.local but i have to call backend from front, and it doesn’t work, dev.backend.local is not recognized (I have symfony error : Couldn’t connect to server for “http://dev.backend.local“).

How can i force front nginx to “see” backend url ? I see nginx proxy but I don’t know how to do that in my case, and if it is really mandatory.

Excuse me for my bad english…

Thanks

docker-compose.yaml :

version: '3.7'

services:
  mysql:
    build:
      context: .
      dockerfile: docker/mariadb/Dockerfile
    ports:
      - '13306:3306'
    restart: always
    volumes:
      - './database/:/var/lib/mysql'
    networks:
      api_network:
        ipv4_address: 172.28.1.4

  php:
    container_name: backend
    build:
      context: .
      dockerfile: docker/backend/Dockerfile
    env_file:
      - .env
    ports:
      - '9001:9001'
    links:
      - mysql:db
    volumes:
      - './app/backend/:/var/www/app/backend:cached'
      - './logs/xdebug:/var/log/xdebug:cached'
    networks:
      api_network:
        ipv4_address: 172.28.1.1

  front:
    container_name: front-web
    build:
      context: .
      dockerfile: docker/front/Dockerfile
    env_file:
      - .env
    ports:
      - '9002:9002'
    links:
      - mysql:db
    volumes:
      - './app/front/:/var/www/app/front'
    networks:
      api_network:
        ipv4_address: 172.28.1.6


  nginx:
    container_name: nginx
    build: ./docker/nginx
    ports:
      - '80:80'
    links:
      - php
      - phpmyadmin
      - front
    volumes:
      - './docker/nginx/conf:/etc/nginx/conf.d/:cached'
      - './app/backend/:/var/www/app/backend:cached'
      - './app/front/:/var/www/app/front:cached'
    depends_on:
      - php
      - front
    networks:
      api_network:
        ipv4_address: 172.28.1.2

  phpmyadmin:
    container_name: phpmyadmin
    image: phpmyadmin/phpmyadmin
    ports:
      - '8080:80'
    links:
      - mysql:db
    environment:
      MYSQL_ROOT_PASSWORD: ****
    networks:
      api_network:
        ipv4_address: 172.28.1.3

networks:
  api_network:
    ipam:
      driver: default
      config:
        - subnet: 172.28.0.0/16

nginx front.conf :

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

   server_name dev.front.local;
   root /var/www/app/front/public;

   location / {
        try_files $uri /index.php$is_args$args;
   }

   location ~ ^/.+.php(/|$) {
      fastcgi_pass php-front;
      fastcgi_split_path_info ^(.+.php)(/.*)$;
      include fastcgi_params;
      fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
      fastcgi_param DOCUMENT_ROOT $realpath_root;
      internal;
   }

   location ~ .php$ {
       return 404;
       #error_page 404 /404_error.html;
   }

   error_log /var/log/nginx/front-error.log;
   access_log /var/log/nginx/front-access.log;
}

nginx back.conf :

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

   server_name dev.backend.local;
   root /var/www/app/backend/public;

   location / {
      try_files $uri /index.php$is_args$args;
   }

   location ~ ^/.+.php(/|$) {
      fastcgi_pass php-upstream;
      fastcgi_split_path_info ^(.+.php)(/.*)$;
      include fastcgi_params;
      fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
      fastcgi_param DOCUMENT_ROOT $realpath_root;
      internal;
   }

   error_log /var/log/nginx/backend-error.log;
   access_log /var/log/nginx/backend-access.log;
}

nginx.conf

user www;
worker_processes 4;
pid /run/nginx.pid;

events {
    worker_connections 2048;
    multi_accept on;
    use epoll;
}

http {
    upstream php-upstream {
        server php:9001 max_fails=3 fail_timeout=30;
    }

    upstream php-front {
        server front:9002 max_fails=3 fail_timeout=30;
    }

    server_tokens off;
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 15;
    types_hash_max_size 2048;
    include /etc/nginx/mime.types;
    default_type application/octet-stream;
    access_log off;
    error_log off;
    gzip on;
    gzip_disable "msie6";
    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;
    open_file_cache max=100;
    client_body_temp_path /tmp 1 2;
    client_body_buffer_size 256k;
    client_body_in_file_only off;
}

daemon off;