Create ChainBetwenDAGAndOperatorNotAllowedRule to ease upgrade to Airflow 2.0

[turbaszek]

This issue is part of #8765

Rule

Create ChainBetwenDAGAndOperatorNotAllowedRule which corresponds to

Assigning task to a DAG using bitwise shift (bit-shift) operators are no longer supported

entry in UPDATING.md. This rule should allow users to check if their current configuration needs any adjusting
before migration to Airflow 2.0.

How to guide

To implement a new rule, create a class that inherits from airflow.upgrade.rules.base_rule.BaseRule.
It will be auto-registered and used by airflow upgrade-check command. The custom rule class has to have title,
description properties and should implement check method which returns a list of error messages in case of
incompatibility.

For example:

airflow/airflow/upgrade/rules/conn_type_is_not_nullable.py

Lines 25 to 42 in ea36166

	class ConnTypeIsNotNullableRule(BaseRule):
	title = "Connection.conn_type is not nullable"
	description = """\
	The `conn_type` column in the `connection` table must contain content. Previously, this rule was \
	enforced by application logic, but was not enforced by the database schema.
	If you made any modifications to the table directly, make sure you don't have null in the conn_type column.\
	"""
	@provide_session
	def check(self, session=None):
	invalid_connections = session.query(Connection).filter(Connection.conn_type.is_(None))
	return (
	'Connection<id={}", conn_id={}> have empty conn_type field.'.format(conn.id, conn.conn_id)
	for conn in invalid_connections
	)

Remember to open the PR against v1-10-stable branch.

[jmelot]

Hello, could I please take this one?

[mik-laj]

@jmelot I assigned you to this ticket.

[jmelot]

Thanks, and sorry for taking so long to follow up. I implemented a rule for this that parses the text of the files in the dags folder and looks for bitshift operators being used on DAG instances. I keep wondering if I'm missing a better way to do this, though. Would you please take a quick look and see if this is on track, or if there is a different way of detecting this I should be looking at instead?

[turbaszek]

@jmelot would you mind opening a PR? This will simplify the review :) Please, target the v1-10-stable branch

[turbaszek]

Closed via #11839