Containerize a PHP application
Prerequisites
- You have installed the latest version of Docker Desktop.
- You have a git client. The examples in this section use a command-line based git client, but you can use any client.
Overview
This section walks you through containerizing and running a PHP application.
Get the sample applications
In this guide, you will use a pre-built PHP application. The application uses Composer for library dependency management. You'll serve the application via an Apache web server.
Open a terminal, change directory to a directory that you want to work in, and run the following command to clone the repository.
$ git clone https://github.com/docker/docker-php-sample
The sample application is a basic hello world application and an application that increments a counter in a database. In addition, the application uses PHPUnit for testing.
Create Docker assets
Now that you have an application, you can create the necessary Docker assets to containerize it.
TipGordon, Docker's AI assistant, can generate Docker assets for your project. Ask Gordon to create a Dockerfile, Compose file, and
.dockerignoretailored to your application.
Create the following files in your docker-php-sample directory.
# syntax=docker/dockerfile:1
# Comments are provided throughout this file to help you get started.
# If you need more help, visit the Dockerfile reference guide at
# https://docs.docker.com/go/dockerfile-reference/
################################################################################
# Create a stage for installing app dependencies defined in Composer.
FROM composer:lts as deps
WORKDIR /app
# If your composer.json file defines scripts that run during dependency installation and
# reference your application source files, uncomment the line below to copy all the files
# into this layer.
# COPY . .
# Download dependencies as a separate step to take advantage of Docker's caching.
# Leverage a bind mounts to composer.json and composer.lock to avoid having to copy them
# into this layer.
# Leverage a cache mount to /tmp/cache so that subsequent builds don't have to re-download packages.
RUN --mount=type=bind,source=composer.json,target=composer.json \
--mount=type=bind,source=composer.lock,target=composer.lock \
--mount=type=cache,target=/tmp/cache \
composer install --no-dev --no-interaction
################################################################################
# Create a new stage for running the application that contains the minimal
# runtime dependencies for the application. This often uses a different base
# image from the install or build stage where the necessary files are copied
# from the install stage.
#
# The example below uses the PHP Apache image as the foundation for running the app.
# By specifying the "8.2-apache" tag, it will also use whatever happens to be the
# most recent version of that tag when you build your Dockerfile.
# If reproducibility is important, consider using a specific digest SHA, like
# php@sha256:99cede493dfd88720b610eb8077c8688d3cca50003d76d1d539b0efc8cca72b4.
FROM php:8.2-apache as final
# Your PHP application may require additional PHP extensions to be installed
# manually. For detailed instructions for installing extensions can be found, see
# https://github.com/docker-library/docs/tree/master/php#how-to-install-more-php-extensions
# The following code blocks provide examples that you can edit and use.
#
# Add core PHP extensions, see
# https://github.com/docker-library/docs/tree/master/php#php-core-extensions
# This example adds the apt packages for the 'gd' extension's dependencies and then
# installs the 'gd' extension. For additional tips on running apt-get, see
# https://docs.docker.com/go/dockerfile-aptget-best-practices/
# RUN apt-get update && apt-get install -y \
# libfreetype-dev \
# libjpeg62-turbo-dev \
# libpng-dev \
# && rm -rf /var/lib/apt/lists/* \
# && docker-php-ext-configure gd --with-freetype --with-jpeg \
# && docker-php-ext-install -j$(nproc) gd
#
# Add PECL extensions, see
# https://github.com/docker-library/docs/tree/master/php#pecl-extensions
# This example adds the 'redis' and 'xdebug' extensions.
# RUN pecl install redis-5.3.7 \
# && pecl install xdebug-3.2.1 \
# && docker-php-ext-enable redis xdebug
# Use the default production configuration for PHP runtime arguments, see
# https://github.com/docker-library/docs/tree/master/php#configuration
RUN mv "$PHP_INI_DIR/php.ini-production" "$PHP_INI_DIR/php.ini"
# Copy the app dependencies from the previous install stage.
COPY --from=deps app/vendor/ /var/www/html/vendor
# Copy the app files from the app directory.
COPY ./src /var/www/html
# Switch to a non-privileged user (defined in the base image) that the app will run under.
# See https://docs.docker.com/go/dockerfile-user-best-practices/
USER www-data# Comments are provided throughout this file to help you get started.
# If you need more help, visit the Docker Compose reference guide at
# https://docs.docker.com/go/compose-spec-reference/
# Here the instructions define your application as a service called "server".
# This service is built from the Dockerfile in the current directory.
# You can add other services your application may depend on here, such as a
# database or a cache. For examples, see the Awesome Compose repository:
# https://github.com/docker/awesome-compose
services:
server:
build:
context: .
ports:
- 9000:80
# The commented out section below is an example of how to define a PostgreSQL
# database that your application can use. `depends_on` tells Docker Compose to
# start the database before your application. The `db-data` volume persists the
# database data between container restarts. The `db-password` secret is used
# to set the database password. You must create `db/password.txt` and add
# a password of your choosing to it before running `docker compose up`.
# depends_on:
# db:
# condition: service_healthy
# db:
# image: postgres
# restart: always
# user: postgres
# secrets:
# - db-password
# volumes:
# - db-data:/var/lib/postgresql/data
# environment:
# - POSTGRES_DB=example
# - POSTGRES_PASSWORD_FILE=/run/secrets/db-password
# expose:
# - 5432
# healthcheck:
# test: [ "CMD", "pg_isready" ]
# interval: 10s
# timeout: 5s
# retries: 5
# volumes:
# db-data:
# secrets:
# db-password:
# file: db/password.txt# Include any files or directories that you don't want to be copied to your
# container here (e.g., local build artifacts, temporary files, etc.).
#
# For more help, visit the .dockerignore file reference guide at
# https://docs.docker.com/go/build-context-dockerignore/
**/.classpath
**/.dockerignore
**/.env
**/.git
**/.gitignore
**/.project
**/.settings
**/.toolstarget
**/.vs
**/.vscode
**/.next
**/.cache
**/*.*proj.user
**/*.dbmdl
**/*.jfm
**/charts
**/docker-compose*
**/compose.y*ml
!**/composer.json
!**/composer.lock
**/Dockerfile*
**/node_modules
**/npm-debug.log
**/obj
**/secrets.dev.yaml
**/values.dev.yaml
**/vendor
LICENSE
README.mdYou should now have the following contents in your docker-php-sample
directory.
├── docker-php-sample/
│ ├── .git/
│ ├── src/
│ ├── tests/
│ ├── .dockerignore
│ ├── .gitignore
│ ├── compose.yaml
│ ├── composer.json
│ ├── composer.lock
│ ├── Dockerfile
│ └── README.mdTo learn more about these files, see the following:
Run the application
Inside the docker-php-sample directory, run the following command in a
terminal.
$ docker compose up --build
Open a browser and view the application at http://localhost:9000/hello.php. You should see a simple hello world application.
In the terminal, press ctrl+c to stop the application.
Run the application in the background
You can run the application detached from the terminal by adding the -d
option. Inside the docker-php-sample directory, run the following command
in a terminal.
$ docker compose up --build -d
Open a browser and view the application at http://localhost:9000/hello.php. You should see a simple hello world application.
In the terminal, run the following command to stop the application.
$ docker compose down
For more information about Compose commands, see the Compose CLI reference.
Summary
In this section, you learned how you can containerize and run a simple PHP application using Docker.
Next steps
In the next section, you'll learn how you can develop your application using Docker containers.