You are now able to run Composer via any Docker image ( WI-45865).
In PhpStorm 2019.1.2, this is finally solved. But it could be that this differs from the one you have in your containerized dev environment, or you might not even have a local PHP interpreter at all both of which might cause problems. You needed a local PHP setup in order to run it. While PhpStorm supports PHP interpreters via Docker and Docker-compose, it still had some parts missing. The usage of containerized environments by PHP developers is steadily growing by roughly 12% each year – from 18% in 2017, to 30% in 2018, to 42% in 2019, according to The State of Developer Ecosystem Survey. This release also contains a Blade templates debugging fix, and a bunch of other bug fixes and improvements for PHP, the Web, and includes all the latest improvements made to the IntelliJ Platform. In this second minor update for the PhpStorm 2019.1 we are happy to bring you support for Composer via Docker.