Discussion - Rule 7. Enable interactive usage and one-click execution

[psychemedia]

So this is about usability of the thing being containerised, right?

I think containers can do several things:

• run headless services and expose an HTML UI over http;
• run desktop GUI apps exposed via either an HTML UI over http (eg novnc) or via something like VMC or RDP;
• provide a preconfigured shell environment to work in, eg via ssh;
• run as a command line application to process local files and write local files. I have an old example here; a more recent example is the way Jupyter Book can use a container to build the book pages.

Other Docker images may be built as base containers that are provided simply as a base for other images, and as such offer no UI / expose no "useful" end-user application/service.

This rule also hints at things like repo2docker and services that can be used to 1-click publish and run containerised services if they are suitably exposed.

The rule may also hint at supporting the ability to run tests against the container? (I don't think tests are mentioned anywhere else?)

[psychemedia]

I'm not sure if this fits here, but adding EXPOSE $PORT commands is really useful if you launch containers using Kitematic, because even if you don't map the ports, it shows they are available and the UI allows you to set the port mapping and make the mapped port available on localhost.