How to pass a database connection into Airflow KubernetesPodOperator - kubernetes

Question

I'm having a confusion with KubernetesPodOperator from Airflow, and I'm wondering how to pass the load_users_into_table() function that it has a conn_id parameter stored in connection of Airflow in the Pod ?
In the official doc proposes to put the conn_id in Secret but I don't understand how can I pass it in my function load_users_into_table() after that.
https://airflow.apache.org/docs/stable/kubernetes.html
the function (task) to be executed in the pod:
def load_users_into_table(postgres_hook, schema, path):
gdf = read_csv(path)
gdf.to_sql('users', con=postgres_hook.get_sqlalchemy_engine(), schema=schema)
the dag:
_pg_hook = PostgresHook(postgres_conn_id = _conn_id)
with dag:
test = KubernetesPodOperator(
namespace=namespace,
image=image_name,
cmds=["python", "-c"],
arguments=[load_users_into_table],
labels={"dag-id": dag.dag_id},
name="airflow-test-pod",
task_id="task-1",
is_delete_operator_pod=True,
in_cluster=in_cluster,
get_logs=True,
config_file=config_file,
executor_config={
"KubernetesExecutor": {"request_memory": "512Mi",
"limit_memory": "1024Mi",
"request_cpu": "1",
"limit_cpu": "2"}
}
)

Answer 1

Assuming you want to run with K8sPodOperator, you can use argparse and add arguments to the docker cmd. Something in these lines should do the job:
import argparse
def f(arg):
print(arg)
parser = argparse.ArgumentParser()
parser.add_argument('--foo', help='foo help')
args = parser.parse_args()
if __name__ == '__main__':
f(args.foo)
Dockerfile:
FROM python:3
COPY main.py main.py
CMD ["python", "main.py", "--foo", "somebar"]
There are other ways to solve this such as using secrets, configMaps or even Airflow Variables, but this should get you moving forward.