Ask HN: What's your Docker workflow?

There's too many application out there that seem to cover the basics, but the nitty-gritty details are left out. Basic question is: How do you edit, version and deploy your app? I'm sure it's gets very tricky when I want things like Let's encrypt or CI/CD setup. I'm looking for simple workflows that would reduce vendor lockin to minimal. The promise of Docker is very appealing that I can switch a cloud provider easily, but it would be nice to see how you do it in practice.