sql_alchemy_conn is sqlite instead of postgres

[mcornwell16]

I built the image with all default settings from the repo and noticed that the sql_alchemy_con is a sqlite URL after exec'ing into the local-runner container and running the command airflow config list.

I was investigating because I noticed running airflow variables list after exec'ing into the container returned errors saying the table could not be found.

Here is a snippet from airflow config retrieved from within the container:

alembic_ini_file_path = alembic.ini
sql_alchemy_conn = sqlite:////usr/local/airflow/airflow.db
# sql_alchemy_engine_args = 
sql_engine_encoding = utf-8
# sql_engine_collation_for_ids = 
sql_alchemy_pool_enabled = False
sql_alchemy_pool_size = 5
sql_alchemy_max_overflow = 10
sql_alchemy_pool_recycle = 1800
sql_alchemy_pool_pre_ping = True
sql_alchemy_schema = 
# sql_alchemy_connect_args = 
# sql_alchemy_session_maker = 
load_default_connections = True
max_db_retries = 3
check_migrations = False

Here is the error output when running airflow variables list:

  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/engine/base.py", line 1910, in _execute_context
    self.dialect.do_execute(
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/engine/default.py", line 736, in do_execute
    cursor.execute(statement, parameters)
sqlite3.OperationalError: no such table: variable

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/local/airflow/.local/bin/airflow", line 8, in <module>
    sys.exit(main())
             ^^^^^^
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/airflow/__main__.py", line 62, in main
    args.func(args)
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/airflow/cli/cli_config.py", line 49, in command
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/airflow/utils/cli.py", line 379, in _wrapper
    f(*args, **kwargs)
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/airflow/utils/providers_configuration_loader.py", line 55, in wrapped_function
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/airflow/cli/commands/variable_command.py", line 42, in variables_list
    variables = session.scalars(select(Variable)).all()
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/orm/session.py", line 1778, in scalars
    return self.execute(
           ^^^^^^^^^^^^^
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/orm/session.py", line 1717, in execute
    result = conn._execute_20(statement, params or {}, execution_options)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/engine/base.py", line 1710, in _execute_20
    return meth(self, args_10style, kwargs_10style, execution_options)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/sql/elements.py", line 334, in _execute_on_connection
    return connection._execute_clauseelement(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/engine/base.py", line 1577, in _execute_clauseelement
    ret = self._execute_context(
          ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/engine/base.py", line 1953, in _execute_context
    self._handle_dbapi_exception(
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/engine/base.py", line 2134, in _handle_dbapi_exception
    util.raise_(
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/util/compat.py", line 211, in raise_
    raise exception
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/engine/base.py", line 1910, in _execute_context
    self.dialect.do_execute(
  File "/usr/local/airflow/.local/lib/python3.11/site-packages/sqlalchemy/engine/default.py", line 736, in do_execute
    cursor.execute(statement, parameters)
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such table: variable
[SQL: SELECT variable.val, variable.id, variable."key", variable.description, variable.is_encrypted 
FROM variable]
(Background on this error at: https://sqlalche.me/e/14/e3q8)

On an side - if I set AIRFLOW__DATABASE__SQL_ALCHEMY_CONN=postgresql+psycopg2://airflow:airflow@postgres:5432/airflow in either the docker-compose or .env.localrunner - all works fine. The sql_alchemy_conn gets properly set within the airflow config and running airflow variables list runs without error.