Consider switching to Debian as base image

Currently, we are using Alpine as the base image for almost all services. At the time, this was the recommended base image and Docker themself move their own images on Alpine too.

2020 could be the year we switch back to Debian as nowadays they provide official image that no so big (like debian:buster-slim?). Here is some pro/cons:

Pros:

• a dev env more similar to classical prod env
• easier to use latest PHP version (almost impossible with Alpine)
• Alpine uses the musl library instead of classical libc, which used to break some tool like Blackfire

Cons:

• base image a bit bigger (~5Mo VS 60Mo)
• more different base images among all services thus more images to build and store
• bigger and different base images also slow CI build and can cost more credits (but should be less problematic than when we used normal Debian images weighting 500Mo)

Some read:

• https://phusion.github.io/baseimage-docker/
• https://github.com/docker-slim/docker-slim

[lyrixx]

So, what we should do ? We are going a new major release with a big BC break: python 3 + invoke instead of fabric so we have a window to break everything

• 🎉 for sticking on bare alpine
• 🚀 to switch to debian

[bastnic]

And on using default php:alpine image, I never succeded to set my extensions without dealing with big headeach and with no success at all.