initialClusterVersion property

The initial Kubernetes version for this cluster.

Valid versions are those found in validMasterVersions returned by getServerConfig. The version can be upgraded over time; such upgrades are reflected in currentMasterVersion and currentNodeVersion. Users may specify either explicit versions offered by Kubernetes Engine or version aliases, which have the following behavior: - "latest": picks the highest valid Kubernetes version - "1.X": picks the highest valid patch+gke.N patch in the 1.X version - "1.X.Y": picks the highest valid gke.N patch in the 1.X.Y version - "1.X.Y-gke.N": picks an explicit Kubernetes version - "","-": picks the default Kubernetes version