I imagine you are using k8s because you want to learn the platform.
In a real cluster with multiple machines, you don’t know which machine will run your container (that’s the point of clusters).
Do you need to host your files on a storage server and link these files to the containers through nfs.
See this post for an example on his to do it.
My advice would be to have the server running on the cluster serving the static folder mounted through a network drive in the container. Then you just need to sync the content to the drive as the last step in your CI.
Alternatively, you will need to bake the static content in the container but then you will have to host it somewhere for the closer to get.
At least for mastodon, you should be able to subscribe to a relay server to push posts to your instance. I’m not sure if there are open ones. Last time I checked, I couldn’t find one still working (ping me if you find one).
A relay server will push all the messages it knows about to your server so your federated timeline will be less empty.
The organic way to do it is to follow as many accounts as you can and wait for their boosts to come through your instance. The only problem with it is that you usually get the parent posts a a few replies and you will miss 90% of the conversation.
Maybe it’s time to go to the court house and change their name to Lua?