There is one moment about time, I need some sleep after docker run:

docker stop demo_db
docker rm demo_db
docker run --name demo_db -p 5444:5432 -e POSTGRES_USER=user -e POSTGRES_PASSWORD=user -e POSTGRES_DB=demo -d postgres:latest

sleep 3

echo "select version();" | docker exec -i demo_db psql -U user -d demo