k8s federation the hard way script

kubearray.sh

#! /bin/bash
CLUSTERS=( "fed-a" "fed-b" )
ZONES=( "us-central1-a" "us-central1-b")

for i in {0..1}; do
  mkdir -p kubeconfigs/${CLUSTERS[${i}]}/

  SERVER=$(gcloud container clusters describe ${CLUSTERS[${i}]} \
    --zone "${ZONES[${i}]}" \
    --format 'value(endpoint)')

  CERTIFICATE_AUTHORITY_DATA=$(gcloud container clusters describe ${CLUSTERS[${i}]} \
    --zone ${ZONES[${i}]} \
    --format 'value(masterAuth.clusterCaCertificate)')

  CLIENT_CERTIFICATE_DATA=$(gcloud container clusters describe ${CLUSTERS[${i}]} \
    --zone ${ZONES[${i}]} \
    --format 'value(masterAuth.clientCertificate)')

  CLIENT_KEY_DATA=$(gcloud container clusters describe ${CLUSTERS[${i}]} \
    --zone ${ZONES[${i}]} \
    --format 'value(masterAuth.clientKey)')

  kubectl config set-cluster ${CLUSTERS[${i}]} --kubeconfig kubeconfigs/${CLUSTERS[${i}]}/kubeconfig

  kubectl config set clusters.${CLUSTERS[${i}]}.server \
    "https://${SERVER}" \
    --kubeconfig kubeconfigs/${CLUSTERS[${i}]}/kubeconfig

  kubectl config set clusters.${CLUSTERS[${i}]}.certificate-authority-data \
    ${CERTIFICATE_AUTHORITY_DATA} \
    --kubeconfig kubeconfigs/${CLUSTERS[${i}]}/kubeconfig

  kubectl config set-credentials admin --kubeconfig kubeconfigs/${CLUSTERS[${i}]}/kubeconfig

  kubectl config set users.admin.client-certificate-data \
    ${CLIENT_CERTIFICATE_DATA} \
    --kubeconfig kubeconfigs/${CLUSTERS[${i}]}/kubeconfig

  kubectl config set users.admin.client-key-data \
    ${CLIENT_KEY_DATA} \
    --kubeconfig kubeconfigs/${CLUSTERS[${i}]}/kubeconfig

  kubectl config set-context default \
    --cluster=${CLUSTERS[${i}]} \
    --user=admin \
    --kubeconfig kubeconfigs/${CLUSTERS[${i}]}/kubeconfig

  kubectl config use-context default \
    --kubeconfig kubeconfigs/${CLUSTERS[${i}]}/kubeconfig

  cat > clusters/${CLUSTERS[${i}]}.yaml <<EOF
apiVersion: federation/v1beta1
kind: Cluster
metadata:
  name: ${CLUSTERS[${i}]}
spec:
  serverAddressByClientCIDRs:
    - clientCIDR: "0.0.0.0/0"
      serverAddress: "https://${SERVER}"
  secretRef:
    name: ${CLUSTERS[${i}]}
EOF
done