CLI Build Shopware 6 Plugin

It's now possible to only build your Shopware 6 plugin with a built in CLI option of our DEV image.

Use the environment variable BUILD_PLUGIN with the name of your plugin. Now simply start your target Shopware 6 image and bind-mount your plugin temporarily into it. Every artefact of your plugin will now be built with that Shopware version and saved into your plugin folder.

# sample that builds plugin "SamplePlugin" with Shopware 6.4.4.0
docker run --rm -e BUILD_PLUGIN=SamplePlugin -v $(PWD):/var/www/html/custom/plugins/SamplePlugin dockware/dev:6.4.4.0

Thanks for this feature bpesch!