Postgres HA Helm Chart

Highly available PostgreSQL 16 powered by Patroni and the Spilo image. The chart provisions a primary with streaming replicas, automatic failover, and a post-upgrade hook that applies configuration changes via the Patroni API so PostgreSQL reloads without restarts.

Features

• Patroni-managed primary/replica topology with streaming replication and automatic failover
• Read/write (-primary) and read-only (-replica) Services plus a headless service for stable DNS
• Dynamic configuration updates: change patroni.postgresql.parameters and run helm upgrade to apply via Patroni without downtime
• PodDisruptionBudget and soft anti-affinity to keep quorum during maintenance
• RBAC + dedicated ServiceAccount; REST API secured with basic auth

Quick start

# create a namespace (if needed)
kubectl create namespace db || true

# install
helm install nexus-db ./postgres-ha --namespace db

Key endpoints after install (with release name nexus-db):

• Primary (read/write): nexus-db-postgres-ha-primary:5432
• Replicas (read-only): nexus-db-postgres-ha-replica:5432
• Patroni API: port 8008 on each pod or via the services above

To connect locally:

kubectl -n db port-forward svc/nexus-db-postgres-ha-primary 5432:5432
psql "postgresql://postgres:PerkinzkSecure42@127.0.0.1:5432/postgres"

Update these via values.yaml before installing in a real cluster.

Zero-downtime config updates

1. Edit values.yaml (or a custom values file) and change patroni.postgresql.parameters or patroni.synchronousMode.
2. Run helm upgrade <release> ./postgres-ha -f <your-values>.yaml.
3. The post-install,post-upgrade job (<release>-postgres-ha-apply-config) patches the Patroni API with the rendered config map and triggers a PostgreSQL reload—no pod restarts required.

Operational notes

• Default replicaCount is 3; keep it ≥3 for reliable leader election and failover.
• Services expose port 5432 for Postgres and 8008 for the Patroni API. Health checks also use the API.
• Storage defaults to 10Gi ReadWriteOnce PVCs; set storage.storageClassName to target a specific class.

Validation

• helm lint ./postgres-ha (already run locally)