GKE Golden Path Configuration

The golden path is the recommended Autopilot configuration for production clusters. It defines sensible defaults — when the user requests different settings, apply them and note relevant trade-offs. For setting up autoscaling specifically, use gke-cluster-autoscaler for node autoscaling or gke-workload-scaling for workload autoscaling (HPA/VPA).

MCP Tools: get_cluster, create_cluster, update_cluster

Rules

1. Default to the golden path. Use golden path values unless the user requests otherwise. When deviating, note trade-offs but respect the user's choice.
2. Day-0 vs Day-1. Flag Day-0 decisions (networking, private nodes, subnets, IP allocation) prominently — they are hard/impossible to change after creation.
3. Tool preference: MCP > gcloud > kubectl. MCP is preferred as it directly interfaces with GKE APIs with structured data, reducing shell syntax errors and parsing ambiguities. See the gke-basics skill's CLI reference for full coverage matrix and override options. If the user says "use gcloud" or "use kubectl", respect that for the session.
4. Document decisions and rationale, especially for Day-0 choices and golden path deviations.

Required Inputs

If the user is unsure, use golden path defaults.

• Project ID (required)
• Region (required, e.g., us-central1)
• Cluster name (required)
• Environment type: dev/test or production (defaults to production)
• Networking: bring-your-own VPC/subnet or auto-create (default: auto-create)
• Scale expectations: expected node/pod count, workload types
• Cost constraints: Spot VM tolerance, budget considerations

Always-Apply Defaults

Recommended best practices applied by default. If the user requests a different setting, apply it and briefly note the security or operational trade-off.

Customer-Configurable Settings

These have golden path defaults but customers may deviate with valid justification. Ask before changing.

Note: Autopilot selects node machine types automatically (e.g., ek-standard-8 may appear in describe output); the machine type is not customer-configurable in Autopilot. Steer workload placement via ComputeClasses instead.

Guardrails

• Do not request or output secrets (tokens, keys, service account JSON).
• Resolve project/cluster context from the conversation, MCP tools, or gcloud config get-value project; ask the user only if it cannot be resolved.
• For Day-0 decisions, always ask clarifying questions before proceeding.
• For Day-1 features, propose golden path defaults with trade-offs and let the customer confirm.
• Do not promise zero downtime — see Upgrade Disruption below for what to advise instead.
• When auditing existing clusters, compare against golden path and report deviations with severity and remediation.

Upgrade Disruption

Never promise zero downtime for node upgrades, on any configuration. Node upgrades cordon and drain nodes, which evicts Pods. Draining honors PodDisruptionBudgets and terminationGracePeriodSeconds for up to one hour, after which GKE forcefully evicts the remaining Pods so the upgrade can proceed. A PDB narrows the window; it cannot veto the upgrade. Say so plainly rather than implying the disruption can be eliminated.

What to recommend, all four — not a subset:

• PodDisruptionBudgets with minAvailable set so eviction cannot take the last healthy replica. A PDB that can never be satisfied stalls the drain for an hour and then loses anyway.

• At least 2 replicas, spread across zones with topology spread constraints. A single-replica Deployment has downtime by definition.

• Readiness probes that reflect real serving health, so traffic drains before the Pod dies.

• Surge upgrade settings on the node pool. Surge is the default strategy; the default is maxSurge=1, maxUnavailable=0 — one extra node is created and made ready before an old one is drained.

  Setting	Controls	Default
  maxSurge	Additional nodes added per zone during the upgrade	1
  maxUnavailable	Nodes simultaneously unavailable per zone	0

  Nodes upgraded at once is the sum of the two, capped at 20 (Autopilot) and 100 (Standard). Multi-zone node pools upgrade one zone at a time. Raising maxUnavailable trades availability for speed; raising maxSurge trades cost for availability.

Caveat: externalTrafficPolicy: Local does not work with parallel node drains, so it constrains aggressive surge configurations.

For rollback procedures and maintenance windows, see the gke-upgrades skill.

Golden Path Config

See golden-path-autopilot.yaml for the full cluster-level policy settings.