From a project perspective in regards to Asterisk in Docker, it’s been brought up a few times but those who were interested couldn’t agree on what it should look like or how it should work. The most that was done was putting a contributed Dockerfile in the repo, but it hasn’t really been touched. SIP also makes it more difficult to actually deploy, unless you know precisely what you are doing from a network perspective.
So I would start my own Dockerfile, I hate to change hardware and start again with trial error and then success without know if it’s luck or it’s the right recipe.