ain-util | AIN utility

I decided to put the chain and the app in the same container

That was a mistake, I think.

Docker is not a virtual machine. It's a virtual application or process instance.

A Docker container runs a linux distro under the hood, but this is a detail that should be ignored when thinking about the purpose of Docker.

You should think of a Docker container as a single application process, not as a full virtual machine to run generally run multiple processes. This is evidenced by the way Docker will shut the container down once the main process shuts down (the process with PID 1).

I've got a longer post about this, here: https://derickbailey.com/2016/08/29/so-youre-saying-docker-isnt-a-virtual-machine/

Additionally, the RUN multichaind instruction in your dockerfile doesn't run the chain in your image / container. It tells the image to run this instruction during the build process.

A Dockerfile is a list of instructions for building an image. The wording here is important. An image is not executed, it is built. An image is a static, immutable template from which a Container is executed.

RUN multichaind Chain -daemon

By putting this RUN instruction in your image, you are temporarily starting the chain, but it is immediately halted (forcefully) when the image layer is done building. It will not remain running, because an image is not executed, it is built.

My advice is to put the chain in a separate image.

You'll have one image for the chain, and one for the node.js app.

You can use docker-compose to make it easier to run containers from both of these at the same time. Or you can run containers manually from them. Either way, you need two images.