Retrieve Full Connection URI From Airflow Postgres Hook

Is there a neater way to get the complete URI from a Postgres hook? .get_uri() doesn't include the 'extra' params so I am appending them like this: def pg_conn_id_to_uri(postgres_c

Solution 1:

If cleaner doesn't necessarily imply for brevity here, then here's something that might work

from typing import Dict, Any

from psycopg2 import extensions

from airflow.hooks.postgres_hook import PostgresHook
from airflow.models.connection import Connection


def pg_conn_id_to_uri(postgres_conn_id: str) -> str:
    # create hook & conn
    hook: PostgresHook = PostgresHook(postgres_conn_id=postgres_conn_id)
    conn: Connection = hook.get_connection(conn_id=postgres_conn_id)
    # retrieve conn_args & extras
    extras: Dict[str, Any] = conn.extra_dejson
    conn_args: Dict[str, Any] = dict(
        host=conn.host,
        user=conn.login,
        password=conn.password,
        dbname=conn.schema,
        port=conn.port)
    conn_args_with_extras: Dict[str, Any] = {**conn_args, **extras}
    # build and return string
    conn_string: str = extensions.make_dsn(dsn=None, **conn_args_with_extras)
    return conn_string

Note that the snippet is untested

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Of course we can still trim off some more lines from here (for e.g. by using python's syntactic sugar conn.__dict__.items()), but I prefer clarity over brevity

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The hints have been taken from Airflow's & pyscopg2's code itself

• PostgresHook
• pyscopg2