Curl connection refused between applications on Docker container

Instead of adding to extra_hosts of the php-fpm container.Modify the Apache2 container's Backend network definition and add an alias.this was you dont have to keep changing the extra_hosts everytime the ip changes

    networks:        frontend:                      backend:         aliases:          - subdomain.example.app

I figured out what was causing my issue. I needed to add an extra-host to the PHP-FPM section of my docker-compose.yml file. So add:

- "subdomain.example.app:10.0.75.1"

To extra-hosts. Then you need to rebuild your containers:

docker-compose up -d --build apache2 mysql redis

And this is what the PHP-FPM section of your docker-compose.yml for Laradock should look like:

php-fpm:      build:        context: ./php-fpm        args:          - INSTALL_XDEBUG=${PHP_FPM_INSTALL_XDEBUG}          - INSTALL_BLACKFIRE=${INSTALL_BLACKFIRE}          - INSTALL_SOAP=${PHP_FPM_INSTALL_SOAP}          - INSTALL_MONGO=${PHP_FPM_INSTALL_MONGO}          - INSTALL_ZIP_ARCHIVE=${PHP_FPM_INSTALL_ZIP_ARCHIVE}          - INSTALL_BCMATH=${PHP_FPM_INSTALL_BCMATH}          - INSTALL_PHPREDIS=${PHP_FPM_INSTALL_PHPREDIS}          - INSTALL_MEMCACHED=${PHP_FPM_INSTALL_MEMCACHED}          - INSTALL_OPCACHE=${PHP_FPM_INSTALL_OPCACHE}          - INSTALL_EXIF=${PHP_FPM_INSTALL_EXIF}          - INSTALL_AEROSPIKE_EXTENSION=${PHP_FPM_INSTALL_AEROSPIKE_EXTENSION}          - INSTALL_MYSQLI=true          - INSTALL_TOKENIZER=${PHP_FPM_INSTALL_TOKENIZER}          - INSTALL_INTL=${PHP_FPM_INSTALL_INTL}          - INSTALL_GHOSTSCRIPT=${PHP_FPM_INSTALL_GHOSTSCRIPT}        dockerfile: "Dockerfile-${PHP_VERSION}"      volumes_from:        - applications      volumes:        - ./php-fpm/php${PHP_VERSION}.ini:/usr/local/etc/php/php.ini      expose:        - "9000"      depends_on:        - workspace      extra_hosts:        - "dockerhost:${DOCKER_HOST_IP}"        - "subdomain.example.app:10.0.75.1"      environment:        - PHP_IDE_CONFIG=${PHP_IDE_CONFIG}      networks:        - backend