In my experience, "slim" Debian images (like `python:slim`) aren't significantly larger than Alpine-based ones, but save lots of time and headache when something assumes glibc and breaks (or, worse - subtly breaks) with musl (or doesn't have a binary distribution for musl so every time image's built you have to build from source).

Also, I'm not sure what are the benefits going `FROM alpine` and installing nginx, than just starting `FROM nginx:alpine`. The latter has benefit of a more straightforward update logic when a new nginx version is released - `docker build` will "just" detect this. It won't notice that Alpine repos have an upgrade, though, and will reuse cached layers for `RUN apk install nginx`.

Just saying.