HA postgresql on kubernetes

Question

I wanted to deploy postgresql as database in my kubernetes cluster. As of now I've followed this tutorial .

By reading the whole thing I understood that we claimed a static storage before initiating the postgresql so that we have the data in case the pod fails. Also we can do replication by pointing to the same storage space to get our data back.

What happens if we use two workers nodes and the pods containing the database migrate to another node? I don't think local storage will work.

Answer 1

hostPath volume is not recommended for production usage because of its ephemeral nature which means if the pod is rescheduled to another node the storage is not migrated and if the node reboots the data is lost.

For durable storage use external block or file storage systems mounted on the nodes using a supported CSI driver

For HA postgres I suggest you explore Postgres Operator which delivers an easy to run highly-available PostgreSQL clusters on Kubernetes (K8s) powered by Patroni. It is configured only through Postgres manifests (CRDs) to ease integration into automated CI/CD pipelines with no access to Kubernetes API directly, promoting infrastructure as code vs manual operations