Kubeblocks Engine Postgresql

PostgreSQL Engine Entry

Use this as the primary create-time entry for PostgreSQL. Tier-1 PostgreSQL never falls back to kubeblocks-engine-generic.

Cold-Start Contract

• Run kubeblocks-preflight whenever the environment is not already profiled.
• Treat engine-create-matrix as the create-time truth for topology, version strategy, sizing, validation, next hops, and forbidden routes.
• Use observability-capability-matrix before promising scrape, dashboard, or alert readiness.
• Keep the legacy kubeblocks-addon-postgresql path as preserved detail only, not as the primary cold-start route.

Topology Selection

• Default topology: replication
• replication: the normal Patroni-style HA path and the default choice for nearly every PostgreSQL rollout.
• replication-with-etcd: use only when the platform explicitly requires an external etcd-backed DCS shape instead of the default addon path.
• If the user does not know why they need replication-with-etcd, stay on replication.

ServiceVersion / Version Strategy

• Strategy: use the stable addon default from current examples unless the user explicitly pins a serviceVersion
• Current addon evidence surfaces supported lines across PostgreSQL 12, 14, 15, 16, and 17, with stable examples anchored on the shipped defaults.
• If the user asks for "latest", stay within addon-backed supported lines rather than inventing a raw image tag.

Preflight Interpretation

• storage_class: required before apply because PostgreSQL WAL and data PVCs should not rely on implicit defaults in production.
• volume_binding_mode: if the storage class binds late, confirm zone placement before choosing multi-replica HA.
• addon_readiness: PostgreSQL addon must be installed before rollout.
• observability_mode: PostgreSQL has exporter, scrape, and alert examples, so choose existing-stack vs bootstrap before create.

Sizing Profiles

• demo: a compact replication shape with small PVCs and minimal resources for evaluation.
• production: dedicated storage, anti-affinity or spread constraints from preflight, and observability enabled from day 1.
• Treat replication-with-etcd as an advanced platform shape, not the default recommendation.

Minimal Create Path

apiVersion: apps.kubeblocks.io/v1
kind: Cluster
metadata:
  name: <cluster>
  namespace: <ns>
spec:
  terminationPolicy: Delete

• Do not leave this skill to read raw addon examples before drafting the manifest.
• Set clusterDef: postgresql for every PostgreSQL create path in this wave.
• replication: set topology: replication, keep a single name: postgresql component, and put serviceVersion, replicas, resources, and volumeClaimTemplates on that component.
• replication-with-etcd: still render clusterDef: postgresql with topology: replication, then inject env ETCD3_HOST and leave the Kubernetes DCS env unset so Patroni points at external etcd instead of the in-cluster default.
• Validate with kubectl apply --dry-run=server -f <postgresql-cluster.yaml>.
• Apply with kubectl apply -f <postgresql-cluster.yaml>.
• Watch kubectl get cluster <name> -n <ns> -w until the phase is Running.

Connection and Validation

• Supported connection methods: in-cluster service, port-forward, exposed service
• First validation step: kubectl get cluster <name> -n <ns> and wait for Running.
• Default SQL validation: psql -h <service> -p 5432 -U postgres.
• Validate replication readiness before handoff if the user explicitly asked for HA or failover.

Next Hops

• Day-2 operations currently route to kubeblocks-op-lifecycle, kubeblocks-op-horizontal-scale, kubeblocks-op-reconfigure, kubeblocks-op-backup, and kubeblocks-observability-router.
• Access and connection hardening should route to kubeblocks-manage-accounts and kubeblocks-configure-tls.
• Failed secondaries should route to kubeblocks-rebuild-replica rather than direct pod deletion.
• If the rollout is blocked by a non-Running phase or unresolved storage/platform issue, route to kubeblocks-troubleshoot.

Forbidden Routes

• Never route PostgreSQL create through kubeblocks-engine-generic, kubeblocks-family-sql, kubeblocks-addon-postgresql, or kubeblocks-engine-tidb.
• Do not force PostgreSQL through MySQL- or TiDB-like semantics.

Evidence Anchors

• Use the evidence anchors below only as optional secondary evidence and parity checks after the manifest is already drafted here. A cold-start runtime should not need these files, but a stronger agent may inspect them when available.
• Preserved detail remains in legacy reference.
• Current addon evidence: examples/postgresql/cluster.yaml, examples/postgresql/cluster-with-etcd.yaml.