Fix HttpOperator(deferrable=True) crash when connection has login / password

[nailo2c]

Closes: #46863

Why

If an HTTP connection contains login/password and the user doesn't set auth_type, the sync path works (the hook auto-defaults to HTTPBasicAuth), but the deferrable path crashes:

airflow/providers/http/src/airflow/providers/http/operators/http.py

Lines 220 to 224 in a8a9fc5

	def execute_async(self, context: Context) -> None:
	self.defer(
	trigger=HttpTrigger(
	http_conn_id=self.http_conn_id,
	auth_type=self.auth_type,

passes None to auth_type, store it in the trigger table.

 id |                    classpath                     |                                                                                                                           kwargs                                                                                                                            |         created_date         | triggerer_id
----+--------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------+--------------
  3 | airflow.providers.http.triggers.http.HttpTrigger | {"__var": {"http_conn_id": "http_default", "method": "GET", "auth_type": null, "endpoint": "get", "headers": {"__var": {}, "__type": "dict"}, "data": {"__var": {}, "__type": "dict"}, "extra_options": {"__var": {}, "__type": "dict"}}, "__type": "dict"} | 2025-06-18 04:01:51.49263+00 |            3
(1 row)

after deserialization, None is passed here, causing 'NoneType' object is not callable error.

airflow/providers/http/src/airflow/providers/http/hooks/http.py

Lines 439 to 440 in a8a9fc5

	if conn.login:
	auth = self.auth_type(conn.login, conn.password)

How

1. Add _resolve_auth_type() to HttpOperator;
   it auto-picks aiohttp.BasicAuth (when the conn has login/password) before deferral.

2. Add serialize_auth_type(); always store the fully-qualified class path or None.

3. Add deserialize_auth_type();
   HttpTrigger.__init__() uses it to turn the stored string back into the class object at runtime.

4. Serialize auth_type when HttpOperator.execute_async() and deserialises it when HttpTrigger.__init__(),
   so internal logic remains unchanged.

What

Test DAG

from airflow import DAG
from airflow.providers.http.operators.http import HttpOperator
import pendulum

with DAG(
    dag_id="http_deferrable_bug_demo",
    start_date=pendulum.datetime(2025, 1, 1, tz="UTC"),
    schedule=None,
    catchup=False,
) as dag:
    HttpOperator(
        task_id="call_httpbin",
        http_conn_id="http_default",
        endpoint="get",
        method="GET",
        deferrable=True,
    )

Test connection

airflow connections add 'http_default' \
  --conn-type http \
  --conn-host 'https://httpbin.org' \
  --conn-login 'user' \
  --conn-password 'pass'

before

after

the auth_type in the trigger table

 id |                    classpath                     |                                                                                                                                       kwargs                                                                                                                                       |         created_date          | triggerer_id
----+--------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------------------------+--------------
  1 | airflow.providers.http.triggers.http.HttpTrigger | {"__var": {"http_conn_id": "http_default", "method": "GET", "auth_type": "aiohttp.helpers.BasicAuth", "endpoint": "get", "headers": {"__var": {}, "__type": "dict"}, "data": {"__var": {}, "__type": "dict"}, "extra_options": {"__var": {}, "__type": "dict"}}, "__type": "dict"} | 2025-06-19 22:52:32.606647+00 |            2
(1 row)

[potiuk]

Great catch and good implementation.