Two PHP sites under Docker + nginx cant communicate with each other

I am using Docker + NGINX to host two PHP sites. The sites are accessible from the outside but the problem arises when I try to access one site from another using cURL or file_get_contents.

The connection gets refused.

the two sites has two separate .conf files. like the one below.

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

    # For https
    # listen 443 ssl;
    # listen [::]:443 ssl ipv6only=on;
    # ssl_certificate /etc/nginx/ssl/default.crt;
    # ssl_certificate_key /etc/nginx/ssl/default.key;

    server_name woostore.test;
    root /var/www/wordpress;
    index index.php index.html index.htm;

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

    location ~ \.php$ {
        try_files $uri /index.php =404;
        fastcgi_pass php-upstream;
        fastcgi_index index.php;
        fastcgi_buffers 16 16k;
        fastcgi_buffer_size 32k;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        #fixes timeouts
        fastcgi_read_timeout 600;
        include fastcgi_params;
    }

    location ~ /\.ht {
        deny all;
    }

    location /.well-known/acme-challenge/ {
        root /var/www/letsencrypt/;
        log_not_found off;
    }

    error_log /var/log/nginx/laravel_error.log;
    access_log /var/log/nginx/laravel_access.log;
}

Nginx Docker file

FROM nginx:alpine

LABEL maintainer="Mahmoud Zalt <[email protected]>"

COPY nginx.conf /etc/nginx/

# If you're in China, or you need to change sources, will be set CHANGE_SOURCE to true in .env.

ARG CHANGE_SOURCE=false
RUN if [ ${CHANGE_SOURCE} = true ]; then \
    # Change application source from dl-cdn.alpinelinux.org to aliyun source
    sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/' /etc/apk/repositories \
;fi

RUN apk update \
    && apk upgrade \
    && apk --update add logrotate \
    && apk add --no-cache openssl \
    && apk add --no-cache bash

RUN apk add --no-cache curl

RUN set -x ; \
    addgroup -g 82 -S www-data ; \
    adduser -u 82 -D -S -G www-data www-data && exit 0 ; exit 1

ARG PHP_UPSTREAM_CONTAINER=php-fpm
ARG PHP_UPSTREAM_PORT=9000

# Create 'messages' file used from 'logrotate'
RUN touch /var/log/messages

# Copy 'logrotate' config file
COPY logrotate/nginx /etc/logrotate.d/

# Set upstream conf and remove the default conf
RUN echo "upstream php-upstream { server ${PHP_UPSTREAM_CONTAINER}:${PHP_UPSTREAM_PORT}; }" > /etc/nginx/conf.d/upstream.conf \
    && rm /etc/nginx/conf.d/default.conf

ADD ./startup.sh /opt/startup.sh
RUN sed -i 's/\r//g' /opt/startup.sh
CMD ["/bin/bash", "/opt/startup.sh"]

EXPOSE 80 81 443

nginx service in docker-compose.yml

nginx:
  build:
    context: ./nginx
    args:
      - CHANGE_SOURCE=${CHANGE_SOURCE}
      - PHP_UPSTREAM_CONTAINER=${NGINX_PHP_UPSTREAM_CONTAINER}
      - PHP_UPSTREAM_PORT=${NGINX_PHP_UPSTREAM_PORT}
      - http_proxy
      - https_proxy
      - no_proxy
  volumes:
    - ${APP_CODE_PATH_HOST}:${APP_CODE_PATH_CONTAINER}${APP_CODE_CONTAINER_FLAG}
    - ${NGINX_HOST_LOG_PATH}:/var/log/nginx
    - ${NGINX_SITES_PATH}:/etc/nginx/sites-available
    - ${NGINX_SSL_PATH}:/etc/nginx/ssl
  ports:
    - "${NGINX_HOST_HTTP_PORT}:80"
    - "${NGINX_HOST_HTTPS_PORT}:443"
    - "${VARNISH_BACKEND_PORT}:81"
  depends_on:
    - php-fpm
  networks:
    - frontend
    - backend

Your services are running in separate Docker containers and each container is isolated and has its own network stack so they cant communicate.

First lets define a network in the networks section of your docker-compose.yml file.

networks:
  mynetwork:

then In the services section of your docker-compose.yml file, add a networks key to each service that needs to communicate with other services.

services:
  service1:
    networks:
      - mynetwork
  service2:
    networks:
      - mynetwork

now it should work, you can access service1 from service2 by using http://service1