Has anyone actually used it?
If you haven't jumped on the bandwagon yet, don't do it. It's a sucker's game.
I got sucked into the Docker hype some years ago and the demos worked well enough in isolation.
I pushed it on a small team that didn't need it. One of the biggest regrets of my career.
Docker may be useful if an application has enormous reach and needs Google scale, but very few apps do.
1) It is incredibly slow to build
2) It is slow to run
3) It is an unbelievable resource hog
4) It has an entirely new set of problems (file system, networking, etc.) that must be understood to get it working
5) Hard deploy time dependency on Docker's web app?!
6) If you do not believe me on the complexity, just observe how docker arguments always seem to turn into k8s (or other orchestration) arguments. It is hard to reason about, hard to deploy, hard to coordinate.
K8s is a total disaster for a small team working on a small project.
We lost many months by choosing these tools for a startup that didn't (yet) need them, and the ongoing, neverending pile of problems and distractions they generated was shocking.
I still feel bad about it. The company could have run on a couple $400 machines under a desk for years, but instead spent tens of thousands on AWS services it didn't need.
Of course, YMMV