external-snapshotter/util.sh

#!/usr/bin/env bash

# Copyright 2014 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.

function kube::util::sourced_variable {
  # Call this function to tell shellcheck that a variable is supposed to
  # be used from other calling context. This helps quiet an "unused
  # variable" warning from shellcheck and also document your code.
  true
}

kube::util::sortable_date() {
  date "+%Y%m%d-%H%M%S"
}

# arguments: target, item1, item2, item3, ...
# returns 0 if target is in the given items, 1 otherwise.
kube::util::array_contains() {
  local search="$1"
  local element
  shift
  for element; do
    if [[ "${element}" == "${search}" ]]; then
      return 0
     fi
  done
  return 1
}

# Example:  kube::util::trap_add 'echo "in trap DEBUG"' DEBUG
# See: http://stackoverflow.com/questions/3338030/multiple-bash-traps-for-the-same-signal
kube::util::trap_add() {
  local trap_add_cmd
  trap_add_cmd=$1
  shift

  for trap_add_name in "$@"; do
    local existing_cmd
    local new_cmd

    # Grab the currently defined trap commands for this trap
    existing_cmd=$(trap -p "${trap_add_name}" |  awk -F"'" '{print $2}')

    if [[ -z "${existing_cmd}" ]]; then
      new_cmd="${trap_add_cmd}"
    else
      new_cmd="${trap_add_cmd};${existing_cmd}"
    fi

    # Assign the test. Disable the shellcheck warning telling that trap
    # commands should be single quoted to avoid evaluating them at this
    # point instead evaluating them at run time. The logic of adding new
    # commands to a single trap requires them to be evaluated right away.
    # shellcheck disable=SC2064
    trap "${new_cmd}" "${trap_add_name}"
  done
}

kube::util::download_file() {
  local -r url=$1
  local -r destination_file=$2

  rm "${destination_file}" 2&> /dev/null || true

  for i in $(seq 5)
  do
    if ! curl -fsSL --retry 3 --keepalive-time 2 "${url}" -o "${destination_file}"; then
      echo "Downloading ${url} failed. $((5-i)) retries left."
      sleep 1
    else
      echo "Downloading ${url} succeed"
      return 0
    fi
  done
  return 1
}

# Wait for background jobs to finish. Return with
# an error status if any of the jobs failed.
kube::util::wait-for-jobs() {
  local fail=0
  local job
  for job in $(jobs -p); do
    wait "${job}" || fail=$((fail + 1))
  done
  return ${fail}
}

# kube::util::join <delim> <list...>
# Concatenates the list elements with the delimiter passed as first parameter
#
# Ex: kube::util::join , a b c
#  -> a,b,c
function kube::util::join {
  local IFS="$1"
  shift
  echo "$*"
}

# kube::util::check-file-in-alphabetical-order <file>
# Check that the file is in alphabetical order
#
function kube::util::check-file-in-alphabetical-order {
  local failure_file="$1"
  if ! diff -u "${failure_file}" <(LC_ALL=C sort "${failure_file}"); then
    {
      echo
      echo "${failure_file} is not in alphabetical order. Please sort it:"
      echo
      echo "  LC_ALL=C sort -o ${failure_file} ${failure_file}"
      echo
    } >&2
    false
  fi
}

# Some useful colors.
if [[ -z "${color_start-}" ]]; then
  declare -r color_start="\033["
  declare -r color_red="${color_start}0;31m"
  declare -r color_yellow="${color_start}0;33m"
  declare -r color_green="${color_start}0;32m"
  declare -r color_blue="${color_start}1;34m"
  declare -r color_cyan="${color_start}1;36m"
  declare -r color_norm="${color_start}0m"

  kube::util::sourced_variable "${color_start}"
  kube::util::sourced_variable "${color_red}"
  kube::util::sourced_variable "${color_yellow}"
  kube::util::sourced_variable "${color_green}"
  kube::util::sourced_variable "${color_blue}"
  kube::util::sourced_variable "${color_cyan}"
  kube::util::sourced_variable "${color_norm}"
fi

# ex: ts=2 sw=2 et filetype=sh