In broad strokes, if you did want to crank up Discourse with k8s, you’d start with a normal two-container install (or look at topics about using an external database), build an image with launcher, then push that image to a repo. You can use ./launcher start-cmd web_only to see what ENV variables you’d need to pass to the container to make it work.
If you have a specific question, you can open a new topic.