Debug PHP container using Xdebug and PhpStorm

Translation of the article prepared in advance of the start of the course “Backend PHP Developer”.

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Docker Instruction # 9: xdebug

I will create a very simple php page and run it with xdebug and PhpStorm.

Source files can be found here:
github.com/ikknd/docker-study in recipe-09 folder

1. Create a “Dockerfile” in the “docker” folder:

FROM php:7.2-fpm

#Install xdebug
RUN pecl install xdebug-2.6.1 && docker-php-ext-enable xdebug

CMD ["php-fpm"]

Run this command from the docker folder to create the image:

docker build -t php-xdebug-custom -f Dockerfile .

2. Create the docker-compose.yml file in the docker folder:

version: "3.7"

services:

  web:
    image: nginx:1.17
    ports:
      - 80:80
    volumes:
      - /var/www/docker-study.loc/recipe-09/php:/var/www/myapp
      - /var/www/docker-study.loc/recipe-09/docker/site.conf:/etc/nginx/conf.d/site.conf
    depends_on:
      - php

  php:
    image: php-xdebug-custom
    volumes:
      - /var/www/docker-study.loc/recipe-09/php:/var/www/myapp
      - /var/www/docker-study.loc/recipe-09/docker/php.ini:/usr/local/etc/php/php.ini

Here I use the php-xdebug-custom image instead of php: 7.2-fpm

3. Make the following settings in the php.ini file:

[xdebug]
zend_extension=xdebug.so
xdebug.profiler_enable=1
xdebug.remote_enable=1
xdebug.remote_handler=dbgp
xdebug.remote_mode=req
xdebug.remote_host=host.docker.internal
xdebug.remote_port=9000
xdebug.remote_autostart=1
xdebug.remote_connect_back=1
xdebug.idekey=PHPSTORM

4. Configure the server in PhpStorm:

File -> Settings -> Languages ​​and Frameworks -> PHP -> Servers

Add a new server using the + icon and configure it as shown in the following screenshot:

Make sure you check “Use path mappings” and map the php folder to /var/www/myapp.

5. Configure the remote PHP debugger in PhpStorm:

Run -> Edit configurations -> PHP Remote Debug

Add a new configuration and assign values ​​to it, as in the following screenshot:

6. Select debug configuration in the phpStorm debug panel

7. Go to /var/www/docker-study.loc/recipe-09/docker/ and execute:

docker-compose up -d

If I introduce now myapp.loc/ in the browser, I will see the results from the file index.php.

I can set a breakpoint, start listening for connections in the PhpStorm debug panel and reload the page.

Have a good debug!

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