Docker-Compose

version: '2'
services:
  picoshare:
    environment:
      - PORT=3002
      - PS_SHARED_SECRET=mypassword
    ports:
      - 3002:3002
    volumes:
      - picoshare:/data
    container_name: picoshare
    image: mtlynch/picoshare:latest

volumes:
  picoshare:

Note: I changed the volume to a Docker volume instead of a mounted volume since it's just storing a database. This was a personal choice. Please adjust for your needs.