Kubernetes Version Monitoring

November 11, 2025 ยท View on GitHub

version-checker now includes built-in Kubernetes cluster version monitoring capabilities. This feature automatically compares your cluster's current Kubernetes version against the latest available versions from official Kubernetes release channels.

How It Works

The Kubernetes version checker:

  • Fetches the current cluster version using the Kubernetes Discovery API
  • Compares it against the latest version from the configured Kubernetes release channel (using official https://dl.k8s.io/release/ endpoints)
  • Exposes the comparison as Prometheus metrics for monitoring and alerting
  • Strips metadata from versions for accurate semantic version comparison (e.g., v1.28.2-gke.1 becomes v1.28.2)

Configuration

You can configure the Kubernetes version checking behavior using the following CLI flags:

  • --kube-channel: Specifies which Kubernetes release channel to check against (default: "stable")
    • Examples: stable, latest, stable-1.28, latest-1.29
  • --kube-interval: How often to check for Kubernetes version updates (default: same as --cache-sync-period, 5 hours)

Metrics

The Kubernetes version monitoring exposes the following Prometheus metric:

version_checker_is_latest_kube_version{current_version="1.28.2", latest_version="1.29.1", channel="stable"} 0
  • Value 1: Cluster is running the latest version from the specified channel
  • Value 0: Cluster is not running the latest version (update available)

Supported Channels

version-checker uses official Kubernetes release channels:

  • stable - Latest stable Kubernetes release (recommended)
  • latest - Latest Kubernetes release (including pre-releases)
  • latest-1.28 - Latest patch for Kubernetes 1.28.x
  • latest-1.27 - Latest patch for Kubernetes 1.27.x

Examples

# Check against latest stable Kubernetes
version-checker --kube-version-channel=stable

# Check against latest Kubernetes (including alpha/beta)
version-checker --kube-version-channel=latest

# Check against latest 1.28.x patch
version-checker --kube-version-channel=latest-1.28

# Monitor against a specific version channel with custom interval
./version-checker --kube-channel=stable-1.28 --kube-interval=1h

Managed Kubernetes Support

Works with all managed Kubernetes services:

  • Amazon EKS: Compares v1.28.2-eks-abc123 against upstream v1.28.2
  • Google GKE: Compares v1.28.2-gke.1034000 against upstream v1.28.2
  • Azure AKS: Compares v1.28.2-aks-xyz789 against upstream v1.28.2