gke-basics

---
name: gke-basics
description: >-
license: Apache-2.0
---

# GKE Basics & Critical Gotchas

Managed Kubernetes platform on Google Cloud. Defaults to Autopilot mode unless Standard is explicitly required.

## Key Selection Rules: Autopilot vs. Standard

* **Default to Autopilot** for almost all workloads.
* **Use Standard ONLY if:**
  * Custom node OS kernel parameters (`sysctl`) are required.
  * Custom node taints or specific hardware node pools are required.
  * DaemonSets require raw `hostPath` mounts to the host OS filesystem.
* When explaining why Standard is required over Autopilot, explicitly cite all matching restrictions (e.g., custom sysctls and custom node taints).
* *For advanced cluster architecture or complex node pool creation planning, refer to `gke-cluster-creation`.*

## Critical Gotchas & Best Practices

1. **Private Autopilot Clusters:**
   * Use `--enable-private-nodes` for private node IP addresses.
   * Use `--enable-private-endpoint` to disable public IP access to the control plane.
   * Restrict control plane access with `--enable-master-authorized-networks` and `--master-authorized-networks=CIDR_BLOCK`:
     ```bash
     gcloud container clusters create-auto CLUSTER_NAME --region=REGION \
       --enable-private-nodes \
       --enable-private-endpoint \
       --enable-master-authorized-networks \
       --master-authorized-networks=CIDR_BLOCK
     ```

2. **Workload Identity (IAM Binding):**
   * Never mount raw GCP Service Account JSON keys in Pods.
   * Annotate the Kubernetes ServiceAccount (`KSA`) to bind to the Google Service Account (`GSA`):
     ```yaml
     metadata:
       annotations:
         iam.gke.io/gcp-service-account: GSA_NAME@PROJECT_ID.iam.gserviceaccount.com
     ```

3. **Autopilot Resource Requests:**
   * In Autopilot, CPU requests must be specified in increments of 250m (0.25 vCPU). If an unaligned CPU request (e.g., 300m) is requested, round up to the nearest 250m increment (500m / 0.5 vCPU).
   * Resource requests equal limits automatically. Omit `limits` to allow Autopilot to set defaults matching `requests`.

4. **Cluster Credentials:**
   * Always explicitly specify `--region` (for regional clusters) or `--zone` (for zonal clusters) when fetching credentials:
     ```bash
     gcloud container clusters get-credentials CLUSTER_NAME --region=REGION --quiet
     ```

## Reference Directory

-   [Core Concepts](references/core-concepts.md): Architecture, cluster modes (Autopilot vs Standard), networking, scaling, and security model.

-   [CLI Usage & Tool Reference](references/cli-reference.md): Tool preference hierarchy (MCP vs gcloud vs kubectl), `gcloud container` commands, and user preference overrides.

-   [Client Libraries](references/client-library-usage.md): Official Kubernetes and Google Cloud Container client libraries in Python, Go, Node.js, and Java.

-   [MCP Usage](references/mcp-usage.md): Connecting to and using the 23 structured GKE MCP tools for cluster management, K8s resources, and diagnostics.

-   [Infrastructure as Code](references/iac-usage.md): Terraform examples for `google_container_cluster` (Autopilot), Kubernetes provider resources, and YAML samples.