What is the meaning of put a docker in the PI?

Question

I am considering installing a docker on pi 2. But after some research, I find that might not be a good idea.

• docker is not ready for PI yet, there are some solutions, but not pefect, like these:

  https://github.com/stevef1uk/docker_for_rpi

  http://blog.hypriot.com/heavily-armed-after-major-upgrade-raspberry-pi-with-docker-1-dot-5-0

• even thought I can successfully put a docker in a PI, I still have to choose the docker image support ARM processor only. If a build a docker image in a pi, I can not install this image in a non-ARM system. Maybe I am wrong about it

So, only a few rpi OS support docker, and only ARM docker images run on the PI, those 2 conditions limit the docker usage a lot, then why people still like to put docker in a PI?

Answer 1

Docker on the Pi is always going to have limitations based on the hardware specs (processor, memory etc.) of the Pi, but I can think of a couple of reasons people would want to install Docker on a Pi:

• developing docker for the Pi
• testing/evaluating docker,
• evaluating new software
• testing experimental code,
• architecture design (microservices, separation of components, security etc.),
• the geek cred or just to say they did it.

Answer 2

I think Steve missed a few points of what containers are useful for. :-) no offense Steve! ;-)

Running Docker (or LXC/LXD) on the Pi would have the following advantages:

• Easily share your project with others (they docker pull your container image and voilà they can run your project on their Pi);
• Corollary to the previous point: easy installation or deployment of your project on a new Pi (or a new SD card after it was broken ;-) )
• Have more than 1 project on the Pi with different dependencies (aka software stack);
• Security (but there still some work to be done has the Raspbian kernel has no support for AppArmor or user namespace or seccomp filter, and the seccomp user space utilities on Raspbian are too old.;
• And what also Steve mentioned :-)