Nice! When I wanted to drill a bit deeper past docker, this was a great additional resource. https://jvns.ca/blog/2016/10/10/what-even-is-a-container/ definitely demystifies some of the magic.

I recently learned and setup a Docker image. It was a server with a shared directory for wwwhome. My impression of the Docker documentation and tutorial was not good. I had to seek outside help such as this post to learn what was actually going on.

You're correct, the 3 things that docker tutorials get fuzzy on are:

1) shared directories

2) security best practises in 2020. When docker started, everybody ran as root (and had to), but now you specify the user and group.

3) exactly how docker works differently on linux vs. mac os x, since mac is not native linux.

Basically if you can explain the above 3 things, you're a docker user expert.

The 2 things to know when using docker in production are:

1) what to do with logs, which can fill the container fs

2) how to do security updates, preferably without downtime. Most companies are running with fossilized containers.

Basically if you can explain the above 2 things, you're a docker devops expert.

Also, I've struggled with trying to do a minimal docker image with alpine, etc. but then had to blow up to a full centos or ubuntu image to get everything working later. So at larger companies I recommend having a bastard on staff who is available on-call to optimize containers.

Question: How do you manage multiple container types (VMWare, Docker) from a single interface? Am I dreaming?

I'm intending on setting up a R Pi 4 as a container for a few smaller projects. Am I shooting myself in the face by using Pi?

I wish this were on the Docker home page. I too need the occasional refresher but I haven't seen one as well written as this by a long shot.

Thanks for the appreciation - I essentially wrote it for myself because I had the same issue every time I had to deal with a Dockerfile :)