Google Kubernetes Engine (GKE) 
Creating Cluster
When creating the default node pool, ensure that you request a machine type that provides at least 6 GB memory. This provides sufficient resources to enable Juju to be deployed alongside your workloads. The default guided install on the GKE console for ‘my-first-cluster’ does not provide sufficient RAM unless you edit it.
Run gcloud auth login before gcloud container clusters get-credentials
Bootstrapping
Registering:
juju add-k8s --gke gke-juju
Bootstrapping:
juju bootstrap gke-juju
Which returns:
Bootstrap complete, controller "gke-juju-europe-west1" is now available in namespace "controller-gke-juju-europe-west1"