Improve permission handling

[ju5t]

A chmod at the end of entrypoint.sh increases the startup time. It would be better to use COPY --chown and run every command in entrypoint.sh as the www-data-user.

[ju5t]

Most of the permissions can be solved by specifying USER www-data within the Dockerfile. This means we need a (sudo) solution for Apache. Apache binds on port 80.