testing.postgresql can not initdb

Question

I am trying to create a fastAPI app that connects to a PostgreSQL database when running, but to a testing.postgresql one when running tests. This is my code for the connection:

import sqlalchemy
import testing.postgresql
from sqlalchemy.ext.declarative import declarative_base
from app.config import Settings
from databases import Database

from sqlalchemy import (
    create_engine
)

settings = Settings()
if settings.DB_HOST == 'local':
    with testing.postgresql.Postgresql() as postgresql:
        engine = create_engine(postgresql.url())
else:
    db_config = {
        "drivername": "postgresql",
        "host": settings.DB_HOST,
        "username": settings.DB_USER,
        "password": settings.DB_PASSWORD,
        "port": settings.DB_PORT,
        "database": settings.DB_DATABASE
    }

    uri = sqlalchemy.engine.url.URL(**db_config)
    engine = create_engine(uri)

database = Database(str(engine.url))

The problem is that this code raises this exception:

app\db\session.py:13: in <module>
    with testing.postgresql.Postgresql() as postgresql:
autostorevenv\lib\site-packages\testing\common\database.py:92: in __init__
    self.initialize()
autostorevenv\lib\site-packages\testing\postgresql.py:50: in initialize
    self.initdb = find_program('initdb', ['bin'])
autostorevenv\lib\site-packages\testing\postgresql.py:144: in find_program
    raise RuntimeError("command not found: %s" % name)
E   RuntimeError: command not found: initdb

I have found some similar answers, but they all happen in Docker containers, which is not my case, so those answers are not good for my case.

Answer 1

I get the same error if I set my PATH so that initdb is not in it. Apparently testing.postgresql depends on you having the PostgreSQL binaries installed and findable.