gke-basics

# 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.