Mastodon Ports and Initial Usage

I’m playing with the lsio official mastodon docker image and noticed:

  1. When fired up, the docker image clearly indicates it is listening on port 3000, yet the docker.compose.yml file shows ports 80/443. Should the yml file be adjusted to port 3000 - especially when using a reverse proxy like nginx?
  2. I found the mechanisms to generate the secrets (4 values: SECRET_KEY, OTP_SECRET and the 2 VAPID values). Is there anything else that must be done to “initialize” the container? The reason I ask - when I fire up the container, I get a UI with just 2 large mastodon icons - not the typical “home” page I’ve come to know and love.