A Helm chart writes objects when you run helm install or helm upgrade ,

and then it is done. An operator runs in the cluster, watches a custom

resource and keeps acting on it. For a stateless app the difference

hardly matters. For a database it decides what happens when the primary

goes away at night.

This post installs PostgreSQL both ways on the same kind cluster and

measures three things: how long writes stop when the primary pod is

deleted, how long they stop when a parameter that needs a restart

changes, and what happens when someone deletes the Service that clients

use.

Setup

One kind v0.33.0 cluster with a single node running Kubernetes 1.37.0,

Helm 4.3.1, and each setup in its own namespace:

Chart: the Bitnami postgresql chart 18.12.14 from oci://registry-1.docker.io/bitnamicharts/postgresql , with architecture=replication and two read replicas. Its default image is bitnami/postgresql:latest , the only tag Bitnami still publishes for free.…