When installing Airflow in Docker, should the Postgres container for Airflow metadata be installed in the same container or separately?

Question

PostgreSQL

There is a need to use Airflow in a Docker container. Airflow will work with LocalExecutor with Postgres as the backend database.
(1) Postgres needs to be installed in an Airflow container.
(2) Postgres must be installed in a separate container from Airflow.
(3) Postgres needs to be installed on a separate host (there is already a database cluster where it is possible to add an airflow database).
Can't make a choice between (1), (2), (3). Please help me make the right informed choice.

Answer 1

Either 2 or 3. Of these, the choice is already determined by your infrastructure details, deployment requirements and the future of deployment.