pgsu

Connect to an existing PostgreSQL cluster as a PostgreSQL SUPERUSER and execute SQL commands.

psycopg2 has a great API for interacting with PostgreSQL, once you provide it with the connection parameters for a given database. However, what if your desired database and database user do not yet exist? In order to create them, you will need to connect to PostgreSQL as a SUPERUSER.

Features

• autodetects postgres setup, tested on
  • Ubuntu 20.04 & PostgreSQL installed via apt
  • Ubuntu 16.04 & PostgreSQL installed via apt
  • Ubuntu 18.04 & PostgreSQL docker container
  • MacOS 10.15 and PostgreSQL installed via conda
  • Windows Server 2019 and PostgreSQL installed via conda
• uses psycopg2 to connect if possible
• can use sudo to become the postgres UNIX user if necessary/possible (default Ubuntu PostgreSQL setups)

Usage

Python API

from pgsu import PGSU
pgsu = PGSU()  # On Ubuntu, this may prompt for sudo password
pgsu.execute("CREATE USER newuser WITH PASSWORD 'newpassword'")
users = pgsu.execute("SELECT usename FROM pg_user WHERE usename='newuser'")
print(users)

While the main point of the package is to guess how to connect as a postgres superuser, you can also provide partial or all information abut the setup using the dsn parameter. These are the default settings:

from pgsu import PGSU
pgsu = PGSU(dsn={
    'host': None,
    'port': 5432,
    'user': 'postgres',
    'password': None,
    'database': 'template1',  # Note: you cannot drop databases you are connected to
})

Command line tool

The package also comes with a very basic pgsu command line tool that allows users to execute PostgreSQL commands as the superuser:

$ pgsu "SELECT usename FROM pg_user"
Trying to connect to PostgreSQL...
Executing query: SELECT usename FROM pg_user
[('aiida_qs_leopold',),
 ('postgres',)]

Tests

Run the tests as follows:

pip install -e .[testing]
pytest