docker-php-extension-installer

docker-php-extension-installer fixes one of the most annoying parts of PHP in Docker: getting extensions like GD, Xdebug, Redis or Imagick into the official php images. Instead of hunting down system libraries and compiling by hand, you run install-php-extensions gd xdebug. It installs the build packages, compiles, enables the extension and removes what it no longer needs so the image stays small. MIT, free.

Usage is one Dockerfile line: ADD the script from the latest GitHub release, or COPY --from the maintainer's image on Docker Hub or GHCR. It supports Debian images back to Debian 8 and Alpine back to 3.9, pins extension versions (xdebug-^3), and installs Composer too. Nothing to run, nothing to buy. Solo, small and larger teams: free. It replaces hand-written docker-php-ext-install and pecl lines.

The catch: every README example pulls the latest release, and releases go out almost daily, so today's build may run a different script than yesterday's. Some libraries are fetched at their newest upstream version, and some extensions default to non-stable PECL builds. Pin a release tag in production. It's also essentially a one-maintainer project, though a steady one since 2018.