A docker image based on the official PHP:7.4-zts or PHP:8.0-zts images that adds the parallel extension
docker pull sarkedev/php-parallel
docker run --rm -v `pwd`:`pwd` -w `pwd` sarkedev/php-parallel php yourphpfile.php
The default tag latest is based on php:7.4-zts-alpine and the release branch of krakjoe/parallel.
The default is based on the release branch and only builds if the make test succeeds. If you want to try the develop branch you can try the sarkedev/php-parallel:develop and similar tags.
Images are also tagged with the short commit hash of the krakjoe/parallel commit it is building.