Kubeblocks Preflight

KubeBlocks Preflight

Run this skill after KubeBlocks is installed but before first-time database provisioning.

Its job is not only to inspect the cluster. It must also produce a stable environment profile / recommendation bundle that downstream engine-entry skills can use directly.

When To Use

Use this skill when any of the following is true:

• The user is provisioning the first database in a cluster.
• Storage behavior is unknown.
• The cluster spans multiple availability zones.
• Monitoring expectations are unclear.
• The user asks "can I deploy PG/MySQL/Redis here?" before creating the cluster.

Do not skip this step for high-frequency engines such as MySQL or PostgreSQL when rollout readiness is still unknown.

Workflow

- [ ] Step 1: Confirm cluster access and namespace assumptions
- [ ] Step 2: Inspect storage and topology risks
- [ ] Step 3: Inspect addon and snapshot prerequisites
- [ ] Step 4: Inspect monitoring baseline
- [ ] Step 5: Emit the recommendation bundle

Step 1: Confirm Cluster Access

kubectl config current-context
kubectl get nodes -o wide
kubectl get ns

Capture:

• cluster type if known (ACK / EKS / GKE / on-prem / local)
• number of nodes
• node zone / topology labels
• target namespace if already chosen

Step 2: Inspect Storage And Topology Risks

This is the most important gate for real deployments.

kubectl get storageclass
kubectl get storageclass -o yaml
kubectl get nodes -L topology.kubernetes.io/zone,failure-domain.beta.kubernetes.io/zone

Check and record:

• whether a default StorageClass exists
• candidate storageClassName
• volumeBindingMode
• whether the class is topology-aware
• whether multi-AZ scheduling plus Immediate binding can create PV node affinity risk
• whether allowVolumeExpansion is enabled

If the cluster is multi-AZ and the selected class binds volumes immediately to a single zone, mark that as a rollout risk and recommend a topology-aware class with WaitForFirstConsumer.

Step 3: Inspect Addon And Snapshot Prerequisites

helm list -n kb-system
kubectl get volumesnapshotclass 2>/dev/null || true
kubectl api-resources | grep -i snapshot || true

Check and record:

• whether the required addon is already installed
• whether CSI snapshot capability exists if snapshot-based workflows matter
• whether any cluster policy or quota is likely to block rollout

Step 4: Inspect Monitoring Baseline

kubectl get pods -A | grep -E 'prometheus|grafana' || true
kubectl get servicemonitor,podmonitor -A 2>/dev/null || true

Decide which observability path is appropriate:

• existing-stack: Prometheus / Grafana already exists and only integration is needed
• bootstrap-stack: no usable monitoring base exists yet

Also note if exporter presence is enough for now (metrics-ready) or if the user expects dashboards / alerting.

Step 5: Emit The Recommendation Bundle

The output of this skill must be structured enough for downstream skills to consume directly.

Use the schema in references/recommendation-bundle.md.

At minimum, produce:

• storage recommendation
• topology / scheduling risk summary
• recommended engine-entry path
• forbidden generic paths
• demo vs production sizing default
• observability route

Example

environmentProfile:
  clusterType: ack
  multiAZ: true
  targetNamespace: demo
recommendations:
  storage:
    storageClassName: alicloud-disk-topology-alltype
    volumeBindingMode: WaitForFirstConsumer
    topologyAwareRequired: true
  engineEntry:
    recommendedSkill: kubeblocks-addon-postgresql
    forbiddenGenericPaths:
      - kubeblocks-create-cluster
  sizing:
    defaultTier: demo
  observability:
    recommendedSkill: kubeblocks-observability-existing-stack
    readinessTarget: scrape-ready
risks:
  - multi-AZ cluster + immediate-binding storage can strand PVCs in the wrong zone

Exit Criteria

Preflight is complete only when:

• a candidate storageClassName is selected
• topology risk is explicitly judged
• the next engine-entry skill is named
• the observability path is named
• demo vs production sizing guidance is stated

If you cannot answer those five items, preflight is incomplete.