I use a combination of Ansible and Docker. I use it for deploying to embedded platforms where sometimes you just want to reflash the board, or you have to uploa

I use a combination of Ansible and Docker. I use it for deploying to embedded platforms where sometimes you just want to reflash the board, or you have to upload a new kernel image for some reason. Or of course when a new board turns up! The goal is so that a new user can install everything from scratch with one command (which could be wrapped into a pretty GUI). I didn't want to go with storing a flash image because it's a lot of space and not portable. This setup will work on basically any dev board with minimal changes (the docker image is platform agnostic and can also be tested on amd64 as well as arm7 and aarch64). It took a while to set up, but I like using an approach which is very ephemeral - means you're forced to document exactly what you did to get the system to be in that state. And you don't worry that if you fry a board that it'll take days to set up again. Ansible makes it easy to do mundane things like delete the default user and set up a new account, copy over ssh keys for easy access, add services and set up the docker container. Docker has the meaty stuff that takes ages to build and install, so I make sure it works and then save the image for easy download later. What I've currently got going is everything in one repository, it has the playbooks, docker files, tests, service files, etc. I clone that using ansible on the target machine. Ansible then pulls the repo to get new changes and rebuilds the container. The container also adds that repo as a volume so that tests and other things are accessible. I don't store containers, I just spin up a new vm on boot. I do have a "backup" playbook which installs everything inside the container when I want to test outside docker. This has happened a few times when using custom libraries that are specific to the embedded platform that don't come with the docker images (eg hardware accelerated gstreamer plugins come to mind). On the Pi life is a bit better because there are raspbian docker images anyway.