Chainguard Image for php

Minimalist Wolfi-based PHP images for building and running PHP applications. Includes both dev and fpm variants.

Chainguard Images are regularly-updated, minimal container images with low-to-zero CVEs.

Download this Image

This image is available on cgr.dev:

docker pull cgr.dev/ORGANIZATION/php:latest

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard registry.

Compatibility Notes

The Chainguard PHP Image is comparable to the official PHP Image from Docker Hub. However, the Chainguard image does not run as the root user and contains only the minimum set of tools and dependencies needed to function. This means it doesn't include things like a shell or a package manager.

Because PHP applications typically require the installation of third-party dependencies with Composer, using a fully distroless image for building your application would not work. In cases like this, it's recommended that you implement a multi-stage Docker build that uses one of the PHP image's -dev variants to set up the application.

Note that chainguard also offers a php:latest-fpm image. This is the distroless php-fpm image variant, designed to be used together with our Nginx image.

Getting Started

To better understand how you can work with the Chainguard PHP image, we encourage you to check out our guide on getting started with PHP. This resource demonstrates how you can use Chainguard's PHP Image to set up a distroless container image as a runtime to execute a command-line PHP application.

When creating a Dockerfile to extend Chainguard's PHP images, the recommended approach is to set up a multi-stage build so that you're able to install your Composer dependencies on a separate environment and then copy the files over to a smaller production image.

Command-line Scripts and Applications

The following example demonstrates how to set up a multi-stage Dockerfile build in the context of command-line PHP applications:

FROM cgr.dev/chainguard/php:latest-dev AS builder
COPY . /app
RUN cd /app && \
    composer install --no-progress --no-dev --prefer-dist

FROM cgr.dev/chainguard/php:latest
COPY --from=builder /app /app

ENTRYPOINT [ "php", "/app/command" ]

Web Applications and APIs

For web applications, you should follow the same principle, but using the php-fpm variant for the final image. You'll also need a custom nginx.conf file to set up your Nginx service with PHP-FPM.

A good way to test your setup locally is by using Docker Compose. The following docker-compose.yaml file demonstrates how to create a web server environment using the Nginx Chainguard Image:

version: "3.7"
services:
  app:
    image: cgr.dev/chainguard/php:latest-fpm
    restart: unless-stopped
    working_dir: /app
    volumes:
      - ./:/app
    networks:
      - wolfi

  nginx:
    image: cgr.dev/chainguard/nginx
    restart: unless-stopped
    ports:
      - 8000:80
    volumes:
      - ./:/app
      - ./nginx.conf:/etc/nginx/nginx.conf
    networks:
      - wolfi

networks:
  wolfi:
    driver: bridge

Notice that the Nginx service has a volume share to set up a custom config file. The following nginx.conf file sets up Nginx to serve pages from an /app/public folder and redirects requests to .php files to the app service on port 9000.

events {
  worker_connections  1024;
}

http {
    server {
        listen 80;
        index index.php index.html;
        root /app/public;
        location ~ \.php$ {
            try_files $uri =404;
            fastcgi_split_path_info ^(.+\.php)(/.+)$;
            fastcgi_pass app:9000;
            fastcgi_index index.php;
            include fastcgi_params;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            fastcgi_param PATH_INFO $fastcgi_path_info;
        }
        location / {
            try_files $uri $uri/ /index.php?$query_string;
            gzip_static on;
        }
    }
}

Configuration

To install application dependencies from your host machine, you can use the latest-dev variant with a shared volume:

docker run --rm -v ${PWD}:/work --entrypoint composer --user root \
    cgr.dev/chainguard/php:latest-dev \
    install --working-dir=/work

To obtain information about modules available for the Chainguard PHP image, you can run the following command:

docker run --rm --entrypoint php cgr.dev/chainguard/php:latest -m

To obtain detailed information about the environment, you can run a php --info command on any of the image tags and use grep to look for a specific module or extension.

For instance, to check for curl settings, you can run:

docker run --rm cgr.dev/chainguard/php:latest --info | grep curl

Documentation and Resources

• Getting Started with the PHP Chainguard Image
• Migrating to PHP Chainguard Images
• Vulnerability Comparison: php

Contact Support

If you have a Zendesk account (typically set up for you by your Customer Success Manager) you can reach out to Chainguard's Customer Success team through our Zendesk portal.

What are Chainguard Images?

Chainguard Images are a collection of container images designed for security and minimalism.

Many Chainguard Images are distroless; they contain only an open-source application and its runtime dependencies. These images do not even contain a shell or package manager. Chainguard Images are built with Wolfi, our Linux undistro designed to produce container images that meet the requirements of a secure software supply chain.

The main features of Chainguard Images include:

• Minimal design, with no unnecessary software bloat
• Automated nightly builds to ensure Images are completely up-to-date and contain all available security patches
• High quality build-time SBOMs (software bills of materials) attesting the provenance of all artifacts within the Image
• Verifiable signatures provided by Sigstore
• Reproducible builds with Cosign and apko (read more about reproducibility)

-dev Variants

As mentioned previously, Chainguard’s distroless Images have no shell or package manager by default. This is great for security, but sometimes you need these things, especially in builder images. For those cases, most (but not all) Chainguard Images come paired with a -dev variant which does include a shell and package manager.

Although the -dev image variants have similar security features as their distroless versions, such as complete SBOMs and signatures, they feature additional software that is typically not necessary in production environments. The general recommendation is to use the -dev variants only to build the application and then copy all application artifacts into a distroless image, which will result in a final container image that has a minimal attack surface and won’t allow package installations or logins.

That being said, it’s worth noting that -dev variants of Chainguard Images are completely fine to run in production environments. After all, the -dev variants are still more secure than many popular container images based on fully-featured operating systems such as Debian and Ubuntu since they carry less software, follow a more frequent patch cadence, and offer attestations for what they include.

Learn More

To better understand how to work with Chainguard Images, we encourage you to visit Chainguard Academy, our documentation and education platform.