Airflow on K8s

Setup airflow on Kubernetes with Kubernetes Executor and KubernetesPodExecutors

Issues

#1 PostgreSQl increase max connection

Helm airflow does not use the stable/postgresql chart. Check https://github.com/helm/charts/blob/master/stable/airflow/requirements.yaml, and you can find the right postgresql chart.

postgresql:
postgresConfig:
maxConnections: "200"