Create custom image with hooks

Interesting in using this OS for me. I need addition config for device image. It’s mean that image should include:

  1. Network interface configuration to use DHCP by default
  2. SSH user
  3. Docker installed
  4. Docker image imported.

So After research i found that

  1. I can configure netplan using hooks or cloud-init
  2. I can add using make-system-user. BUT i didn’t found how i can add system-user login by user/password (and not key)
  3. I can add using required-snaps key in model.josn
  4. Did’t found Trying to copy docker image on image create process then add it to docker using hooks BUT didn’t found how to copy files to created image