I want a dockerfile to bring up a container wiith php 8.0, supporting german language either in the OS and inside PHP.
The create a user"app"; the user has UID and GID configurable as APP_UID and APP_GID docker build arguments; the arguments have default value 61234.
The basic php extensions should be enabled; especially for XSLT, XML dom operations, german language support; but skip PECL packages and extensions that are unlikely to be used. In any case, don't exceed with the number of extensions installed; this is not a "production" Dockerfile!
Node 14 and npm should be also present in the container.
Switch to the user "app".
Then copy into the container /app folder the composer.json, composer.lock and package.json and package-lock.json from the host machine.
Then install the compser & npm dependencies.
Try to be minimalistic in the instructions; don't repeat too many times the same command. Keep it simple!