PostgreSQL upgrade from 10 to 11

postgres_upgrade.sh

sudo apt install wget ca-certificates
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt/ `lsb_release -cs`-pgdg main" >> /etc/apt/sources.list.d/pgdg.list'

psql --version

sudo apt update
sudo apt install postgresql-11
pg_lsclusters
sudo pg_dropcluster 11 main --stop
sudo pg_upgradecluster 10 main
sudo pg_dropcluster 10 main
pg_lsclusters

dpkg -l | grep postgresql
sudo apt purge postgresql-10 postgresql-client-10 postgresql-contrib-10

psql --version