Versatile Docker Photographs with PHP INI Surroundings Variables

I not too long ago posted about Get Xdebug Working With Docker and PHP 8.4 to indicate you ways simple it’s to get an Xdebug connection working. In that tutorial, I hard-coded INI settings to maintain the tutorial targeted on establishing Xdebug. In an actual software, you need your Docker photographs to be versatile so every developer can configure their very own settings with out affecting the picture configuration.

On this publish, I am going to present you use surroundings variables to make your photographs tremendous versatile. As of v8.3, PHP helps fallback values with the INI surroundings variable syntax, so we are able to actually make our INI configuration clear.

If you happen to reference the earlier tutorial, our xdebug.ini file regarded like the next snippet:

; construct/php/conf.d/xdebug.ini file
[xdebug]
xdebug.mode = debug
 
xdebug.client_host = host.docker.inside
 
; Or use the host machine IP handle:
; xdebug.client_host = 192.168.86.203
 
xdebug.start_with_request = sure

If one other developer in your crew does not wish to begin Xdebug by default, they’d must replace the INI file, and both commit the change or simply revert it. Gross.

That’s no solution to reside, particularly since PHP now helps default fallback values in INI information. Earlier than we get to that, we might additionally configure Xdebug instantly with surroundings variables. The next is equal to our xdebug.ini file:

companies:
  app:
    construct:
      context: .
      dockerfile: construct/Dockerfile
      goal: improvement
    ports:
      - "8080:80"
    volumes:
      - .:/srv/app
    surroundings:
      XDEBUG_CONFIG: "client_host=0.0.0.0 start_with_request=sure"
      XDEBUG_MODE: "debug,develop"

If we moved the surroundings values to an unversioned ENV file, every developer might handle Xdebug settings regionally. One other solution to configure Xdebug is thru INI like we initially did, however utilizing envrionment variables:

; construct/php/conf.d/xdebug.ini file
[xdebug]
xdebug.mode = ${PHP_XDEBUG_MODE:-debug,develop}
 
xdebug.client_host = ${PHP_XDEBUG_CLIENT_HOST:-host.docker.inside}
 
xdebug.start_with_request = ${PHP_XDEBUG_START_WITH_REQUEST:-trigger}

I’ve prefixed these variables with PHP_ to keep away from conflicts and rapidly acknowledge which ENV values have been meant for use with INI configuration. For instance, XDEBUG_MODE is reserved for Xdebug configuration instantly, so if we wish to configure it by way of our INI ENV variable we’d like a novel identify.

If you happen to restart the Docker picture, you possibly can confirm these settings by including phpinfo(); exit; to the highest of public/index.php or connect with the container:

$ docker compose up --build -d
$ docker compose exec app bash
 
# Within the container
$ php -i | grep xdebug.start_with_request
xdebug.start_with_request => set off => set off

If you wish to attempt customizing these values regionally, add the next to your compose.yaml file:

companies:
  app:
    construct:
      context: .
      dockerfile: construct/Dockerfile
      goal: improvement
    ports:
      - "8080:80"
    volumes:
      - .:/srv/app
+    env_file:
+      - .docker.env

Then, create a .docker.env and .docker.env.instance file within the root of your undertaking. Add smart defaults to the instance file and add .docker.env to your .gitignore file. Here is an instance of the contents:

PHP_XDEBUG_MODE=debug
 
PHP_XDEBUG_CLIENT_HOST=host.docker.inside
# Or use your laptop's native community IP
# PHP_XDEBUG_CLIENT_HOST=192.168.86.250
 
PHP_XDEBUG_START_WITH_REQUEST=set off

You will have to recreate the container to see the up to date ENV values, however when you do, it’s best to see your ENV settings take impact:

And that is it, your INI settings are simple to switch with out affecting the picture construct information.

Now you can make your Docker photographs versatile utilizing surroundings variables with INI settings. I additionally confirmed you use Xdebug’s built-in surroundings variables to configure issues in the event you want simplicity. Nonetheless, not all settings might be set by way of the XDEBUG_CONFIG surroundings, so use the strategy of configuration that works greatest for you!