Docker PHP FPM images for development use

This is a PHP FPM Docker image tuned to be used in Docker Compose setups for development environments.

We have tried to hit a sweet stuff between not doing too much magic, but still be an easy fit for how we do work at Reload A/S.

A simple example of usage would be having a php service providing FPM like this:

services:
  php:
    image: 'ghcr.io/reload/php-fpm:8.3'
    ports:
      - '9000'
    user: '${UID:-501}:${GID:-20}'
    volumes:
      - '.:/var/www'
    environment:
      USE_FEATURES: >-
        root-php-ini

PHP versions

We provide PHP 8.1, 8.2, 8.3 and 8.4 images.

The images are based on the official php:8.x-fpm-alpine Docker images. We build new images when new upstream versions are released.

The image has some PHP settings set for development / debugging use, see debug.ini. They can be disabled with no-debug feature mentioned later in this document.

User

The images are designed to be able to run as root inside the container or as UID 501 (macOS typical user ID) or UID 1000 (Linux typical user ID). Other user ID's might work as well.

This being an image for development use, we have installed sudo and configured all users in the container to use it without providing a password.

Volumes

We recommend mounting the project root of your repository into the Docker workdir, /var/www.

PHP Document root

FPM expects PHP's document root to be located in /var/www/web. That would be a web folder inside your project root if you follow our practice.

If you would like the document root to be located elsewhere, you should set the environment variable PHP_DOCUMENT_ROOT to the desired location.

PHP extensions

The images come with the following extensions installed and enabled:

• apcu
• bcmath
• calendar
• ctype
• curl
• dom
• exif
• fileinfo
• ftp
• gd
• gettext
• iconv
• imagick
• intl
• json
• mbstring
• memcache
• memcached
• mysqli
• mysqlnd
• opcache
• pdo
• pdo_mysql
• pdo_sqlite
• phar
• posix
• readline
• redis
• shmop
• simplexml
• soap
• sockets
• sqlite3
• sysvmsg
• sysvsem
• sysvshm
• tokenizer
• xml
• xmlreader
• xmlwriter
• xsl
• zip

In addition, the xdebug and blackfire extensions are installed but not enabled in the images (except on PHP 8.4).

The php-extension-installer tool is installed if you want to install additional extensions yourself.

Entry point scripts

If you place executables (e.g., by mounting them there) in /etc/entrypoint.d they will be run before starting FPM.

Reloading php-fpm

If you have changed PHP configuration or enabled or disabled some PHP extensions, you can restart the php-fpm process with the /usr/local/bin/reload command. E.g.

docker compose exec php reload

"Features"

The images come with a concept called "features".

Features a predefined entry point scripts with common functionality you can opt in to using.

Features a run before the entry point scripts mentioned before.

You opt in to using them by setting the USE_FEATURES to a space separated list of their names.

install-composer-extensions feature

If you have a composer.json in your workdir (/var/www) this feature will locate required dependencies on PHP extensions ext-* and install them using the aforementioned php-extension-installer tool.

Notice: if this needs to install numerous libraries and do a lot of compilation, this could take quite some time when creating the container.

root-php-ini feature

If you have a php.ini in your workdir (/var/www) this will be loaded by FPM.

no-debug feature

Disable the PHP ini settings in debug.ini.

update-ca-certificates

If your container needs to use custom CA certificates, place them in /usr/local/share/ca-certificates/ using volumes and using the feature update-ca-certificates.

services:
  php:
    image: 'ghcr.io/reload/php-fpm:8.3'
    volumes:
      - '.:/var/www'
      - './my-ca.pem:/usr/local/share/ca-certificates/my-ca.pem:ro'
    environment:
      USE_FEATURES: >-
        update-ca-certificates

Xdebug

Xdebug is disabled by default, but the extension is available. To enable the xdebug-extension execute /usr/local/bin/xdebug via Docker, e.g.,

docker exec -it <container id> xdebug

Or via Docker Compose, e.g., if the image is used by a service called php:

docker compose exec php xdebug

The script keeps xdebug enabled while running and is terminated by typing enter.

Blackfire

To send profiles to Blackfire, you'll need to have a Blackfire agent, reachable by the php-fpm image and the appropriate credentials.

Providing an agent in docker compose is easy, as it's just starting the original Blackfire image.

  php:
    image: 'ghcr.io/reload/php-fpm:8.3'
    environment:
      BLACKFIRE_CLIENT_ID: <your client key>
      BLACKFIRE_CLIENT_TOKEN: <your client token>
  blackfire:
    image: 'blackfire/blackfire'
    environment:
      BLACKFIRE_SERVER_ID: <your server key>
      BLACKFIRE_SERVER_TOKEN: <your server token>

The correct ID's and tokens can be found by viewing the Blackfire setup documentation when logged in.

Mail

The image has mstmp installed. msmtp is an SMTP client.

For simple development setups, we recommend combining it with Mailpit:

  php:
    image: 'ghcr.io/reload/php-fpm:8.3'
    environment:
      SMTPSERVER: 'mail'
  mail:
    image: 'axllent/mailpit'
    ports:
      - '25'
      - '80'
    environment:
      MP_SMTP_BIND_ADDR: '0.0.0.0:25'
      MP_UI_BIND_ADDR: '0.0.0.0:80'

For more advanced usages, you can add a system-wide configuration file for msmtp at /etc/msmtprc in the php-fpm image.