#!/bin/bash
set -o errexit

create() {
  set +e
  kind get clusters | grep "${NAME}"
  exitCode=$?
  set -e
  if [ $exitCode -eq "0" ]; then
    echo "kind cluster already exists"
    kubectl config use-context "kind-${NAME}"
    exit 0
  fi

  # create registry container unless it already exists
  reg_name='kind-registry'
  reg_port='5000'
  running="$(docker inspect -f '{{.State.Running}}' "${reg_name}" 2>/dev/null || true)"
  if [ "${running}" != 'true' ]; then
    docker run \
      -d --restart=always -p "127.0.0.1:${reg_port}:5000" --name "${reg_name}" \
      registry:2
  fi

  # create a cluster with the local registry enabled in containerd
  cat <<EOF | kind create cluster --wait 2m0s --name ${NAME} --config=-
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
containerdConfigPatches:
- |-
  [plugins."io.containerd.grpc.v1.cri".registry.mirrors."localhost:${reg_port}"]
    endpoint = ["http://${reg_name}:${reg_port}"]
EOF

  # connect the registry to the cluster network
  # (the network may already be connected)
  docker network connect "kind" "${reg_name}" || true

  # Document the local registry
  # https://github.com/kubernetes/enhancements/tree/master/keps/sig-cluster-lifecycle/generic/1755-communicating-a-local-registry
  cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
  name: local-registry-hosting
  namespace: kube-public
data:
  localRegistryHosting.v1: |
    host: "localhost:${reg_port}"
    help: "https://kind.sigs.k8s.io/docs/user/local-registry/"
EOF
}

delete() {
  kind delete cluster --name "${NAME}"
}

usage() { echo "Usage: $0 [-h help] [-a <delete|[create]>] [-n <kind-test>]" 1>&2; exit 1; }

NAME="kind-test"
ACTION="create"

while getopts ":a:n:h" o; do
  case "${o}" in
    a)
      ACTION="${OPTARG}"
      ;;
    n)
      NAME="${OPTARG}"
      ;;
    h)
      usage
      exit 0
      ;;
    *)
      echo "Invalid flag ${OPTARG};"
      usage
      exit 1
  esac
done
shift $((OPTIND-1))

if [[ "${ACTION}" == "create" ]]; then
  create
elif [[ "${ACTION}" == "delete" ]]; then
  delete
fi