# start old postgres, dump data
sed -i 's/postgres:12-alpine/postgres:10-alpine/' docker-compose.yml
docker-compose exec db pg_dumpall -U partdoc > pgdump.tmp
# migrate to new postgres, import data
docker-compose stop db
sed -i 's/postgres:10-alpine/postgres:12-alpine/' docker-compose.yml
docker-compose up -d
docker-compose exec -T db psql -U partdoc < pgdump.tmp
docker-compose down
docker-compose up -d
rm pgdump.tmp