How to use apt install correctly in your Dockerfile

This is the correct way to use apt install in your Dockerfile:

ENV DEBIAN_FRONTEND=noninteractive
RUN apt update && apt install -y PACKAGE && rm -rf /var/lib/apt/lists/*

Key takeaways:

Set DEBIAN_FRONTEND=noninteractive to prevent some packages from prompting interactive input (tzdata for example), which leads to indefinite waiting for an user input
Run apt update before the install command to fetch the current package lists
apt install with -y to prevent apt from asking you if you really want to install the packages
rm -rf /var/lib/apt/lists/* after the install command in order ot prevent the cached apt lists (which are fetched by apt update) from ending up in the container image
All of that in one command joined by && in order to prevent docker from building separate layers for each part of the command (and to prevent it from first storing /var/lib/apt/lists in one layer and then delete it in another layer)