#!/usr/bin/env bash

# Copyright 2019 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

set -o errexit
set -o nounset
set -o pipefail

BINS=(
  kube-apiserver
  kube-controller-manager
  kube-proxy
  kube-scheduler
  kubectl
  kubelet
)

function array_contains() {
  local search="$1"
  local element
  shift
  for element; do
    if [[ "${element}" == "${search}" ]]; then
      return 0
     fi
  done
  return 1
}

function print_usage() {
  cat <<EOF
Usage:
  $(basename "$0") [command]

Available Commands:
  help                     Help about any command
  kube-apiserver
  kube-controller-manager
  kube-proxy
  kube-scheduler
  kubectl                  kubectl controls the Kubernetes cluster manager
  kubelet
EOF
  exit 0
}

function main() {
  if [[ "$#" -lt 1 || "${1:-}" == "--help" || "${1:-}" == "help" ]]; then
    print_usage
  fi
  if ! array_contains "$1" "${BINS[@]}"; then
    echo "$1: command not supported"
    print_usage
  fi
  command=${1}
  shift
  if ! command -v "${command}" &>/dev/null; then
    echo "${command}: command not found"
    exit 1
  fi
  exec "${command}" "${@}"
}

main "${@}"