New to Docker, Rails project?

Hello. I’m trying to start a rails project with Docker. I’m used to using Vagrant because of the bootcamp I was in. But now that I’m on my own I want to switch after learning what it is. I’ve created a container, I think, for my project, then I ran the code in the docs here: https://docs.docker.com/compose/rails/

There was an issue at first, but got fixed, and I saw in my terminal that all of the rails files created by the rails new command. Now I’m just stuck on how to actually get that rails project image into my container so I can work on it. Nothing in the docs is straight forward enough for me. For example, to run their line:

$ docker run --name some-rails-app -d my-rails-app

I know what my “my-rails-app” name is, but when they say "SOME-rails-app, how is that different than MY-rails-app(actual name is jacks_site). What is my SOME-rails-app? Thank you for any help in advance as I’m completely new to Docker, as I said, and I’m also a very new developer. Just graduated bootcamp in February.

Well, given your example, my-rails-app would be the name of your local image.
That’s what you will see if you type in docker images.

While some-rails-app will be the name of your container. That’s waht you see if you type docker ps

This approach is for scalability reasons. So you can launch multiple containers of the same image …