Run docker-compose up -d
If you're having trouble with path-mapping in a windows environment, set the environment variable export COMPOSE_CONVERT_WINDOWS_PATHS=1.
Place .bak file in ./database-backup-folder created from docker.
Run the following to restore the database:
docker exec -it mssql /opt/mssql-tools/bin/sqlcmd -S localhost -U SA -P "Admin123!" -Q “RESTORE FILELISTONLY FROM DISK = '/var/backup/BACKUPNAME.bak'”