Docker seems to be the feature of web apps deployment. This presentation shows how to use it in PHP development.
Links:
https://registry.hub.docker.com/u/sskorc/silex
https://github.com/sskorc/docker-silex
https://github.com/sskorc/docker-symfony
https://github.com/schibsted-seals/wordpress-docker-example
https://speakerdeck.com/ubermuda/a-multi-container-symfony2-setup-with-docker