[solvedl] Installing wordpress _with_ theme

After searching I found just one version 3 tutorial for wordpress that included a theme directory. And unfortunately I was unable to adapt that for my existing theme.
This is my docker compose file

version: '3'

services:
  db:
    image: mysql:5.7
    volumes:
      - db_data:/var/lib/mysql
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: xxxxxxxx
      MYSQL_DATABASE: wpwp
      MYSQL_USER: abccccc
      MYSQL_PASSWORD: yyyyyy

  wordpress:
    depends_on:
      - db
    image: wordpress:latest
    ports:
      - "8000:80"
    restart: always
    environment:
      WORDPRESS_DB_HOST: db:3306
      WORDPRESS_DB_USER: abccccc
      WORDPRESS_DB_PASSWORD: yyyyyy
    working_dir: /var/www/html
    volumes:
      - /home/simon/code/wp_af2015/wp-content/themes/af2016:/var/www/html/wp-content/themes/my-theme
volumes:
    db_data:

Then I ran docker-compose up -d on my ubuntu 17.10 device, and something shows when I run docker stats but there is no response from locahost:8000

Then I tried without -d and got the following errors

There is something ar /var/www/html indeed, but I thought docker created some sort of private directory structure? Beyond that I see that somethng is wrong with the database stuff but all I did was copy a working example and add other names

What am I getting wrong?

Maybe you should post your solution here for other forum users who might have same issue? Or give some hints how did you find the solution?