quicksetup: creating database with owner fails

[ltalirz]

Connecting to a postgresql cluster as the superuser azureuser on an Azure postgresql database.

Granting all privileges works:

template1=> create database test;
CREATE DATABASE
template1=> create user test;
CREATE ROLE
template1=> grant all privileges on database test to test;
GRANT
template1=> drop database test;
DROP DATABASE

but creating the database with owner test fails:

template1=> create database test owner test;
ERROR:  must be member of role "test"
template1=> grant test to azureuser;
GRANT ROLE
template1=> create database test owner test;
CREATE DATABASE

verdi quicksetup currently creates the database with owner and grants all privileges

aiida-core/aiida/manage/external/postgres.py

Lines 155 to 156 in 2c183fc

	self.execute(_CREATE_DB_COMMAND.format(dbname, dbuser))
	self.execute(_GRANT_PRIV_COMMAND.format(dbname, dbuser))

This is actually overkill: according to the postgres documentation

There is no need to grant privileges to the owner of an object (usually the user that created it), as the owner has all privileges by default. (The owner could, however, choose to revoke some of their own privileges for safety.)

I.e. I propose that we go the

template1=> create user test;
CREATE ROLE
template1=> grant test to azureuser;
GRANT ROLE
template1=> create database test owner test;
CREATE DATABASE

route.

Will open a PR for this.