kubernetes/build/lib/release.sh

#!/usr/bin/env bash

# Copyright 2016 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.

# This file creates release artifacts (tar files, container images) that are
# ready to distribute to install or distribute to end users.

###############################################################################
# Most of the ::release:: namespace functions have been moved to
# github.com/kubernetes/release.  Have a look in that repo and specifically in
# lib/releaselib.sh for ::release::-related functionality.
###############################################################################

# This is where the final release artifacts are created locally
readonly RELEASE_STAGE="${LOCAL_OUTPUT_ROOT}/release-stage"
readonly RELEASE_TARS="${LOCAL_OUTPUT_ROOT}/release-tars"
readonly RELEASE_IMAGES="${LOCAL_OUTPUT_ROOT}/release-images"

KUBE_BUILD_HYPERKUBE=${KUBE_BUILD_HYPERKUBE:-y}

# Validate a ci version
#
# Globals:
#   None
# Arguments:
#   version
# Returns:
#   If version is a valid ci version
# Sets:                    (e.g. for '1.2.3-alpha.4.56+abcdef12345678')
#   VERSION_MAJOR          (e.g. '1')
#   VERSION_MINOR          (e.g. '2')
#   VERSION_PATCH          (e.g. '3')
#   VERSION_PRERELEASE     (e.g. 'alpha')
#   VERSION_PRERELEASE_REV (e.g. '4')
#   VERSION_BUILD_INFO     (e.g. '.56+abcdef12345678')
#   VERSION_COMMITS        (e.g. '56')
function kube::release::parse_and_validate_ci_version() {
  # Accept things like "v1.2.3-alpha.4.56+abcdef12345678" or "v1.2.3-beta.4"
  local -r version_regex="^v(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)-([a-zA-Z0-9]+)\\.(0|[1-9][0-9]*)(\\.(0|[1-9][0-9]*)\\+[0-9a-f]{7,40})?$"
  local -r version="${1-}"
  [[ "${version}" =~ ${version_regex} ]] || {
    kube::log::error "Invalid ci version: '${version}', must match regex ${version_regex}"
    return 1
  }
  VERSION_MAJOR="${BASH_REMATCH[1]}"
  VERSION_MINOR="${BASH_REMATCH[2]}"
  VERSION_PATCH="${BASH_REMATCH[3]}"
  VERSION_PRERELEASE="${BASH_REMATCH[4]}"
  VERSION_PRERELEASE_REV="${BASH_REMATCH[5]}"
  VERSION_BUILD_INFO="${BASH_REMATCH[6]}"
  VERSION_COMMITS="${BASH_REMATCH[7]}"
}

# ---------------------------------------------------------------------------
# Build final release artifacts
function kube::release::clean_cruft() {
  # Clean out cruft
  find "${RELEASE_STAGE}" -name '*~' -exec rm {} \;
  find "${RELEASE_STAGE}" -name '#*#' -exec rm {} \;
  find "${RELEASE_STAGE}" -name '.DS*' -exec rm {} \;
}

function kube::release::package_tarballs() {
  # Clean out any old releases
  rm -rf "${RELEASE_STAGE}" "${RELEASE_TARS}" "${RELEASE_IMAGES}"
  mkdir -p "${RELEASE_TARS}"
  kube::release::package_src_tarball &
  kube::release::package_client_tarballs &
  kube::release::package_kube_manifests_tarball &
  kube::util::wait-for-jobs || { kube::log::error "previous tarball phase failed"; return 1; }

  # _node and _server tarballs depend on _src tarball
  kube::release::package_node_tarballs &
  kube::release::package_server_tarballs &
  kube::util::wait-for-jobs || { kube::log::error "previous tarball phase failed"; return 1; }

  kube::release::package_final_tarball & # _final depends on some of the previous phases
  kube::release::package_test_tarball & # _test doesn't depend on anything
  kube::util::wait-for-jobs || { kube::log::error "previous tarball phase failed"; return 1; }
}

# Package the source code we built, for compliance/licensing/audit/yadda.
function kube::release::package_src_tarball() {
  local -r src_tarball="${RELEASE_TARS}/kubernetes-src.tar.gz"
  kube::log::status "Building tarball: src"
  if [[ "${KUBE_GIT_TREE_STATE-}" == "clean" ]]; then
    git archive -o "${src_tarball}" HEAD
  else
    local source_files=(
      $(cd "${KUBE_ROOT}" && find . -mindepth 1 -maxdepth 1 \
        -not \( \
          \( -path ./_\*        -o \
             -path ./.git\*     -o \
             -path ./.config\* -o \
             -path ./.gsutil\*    \
          \) -prune \
        \))
    )
    "${TAR}" czf "${src_tarball}" -C "${KUBE_ROOT}" "${source_files[@]}"
  fi
}

# Package up all of the cross compiled clients. Over time this should grow into
# a full SDK
function kube::release::package_client_tarballs() {
   # Find all of the built client binaries
  local platform platforms
  platforms=($(cd "${LOCAL_OUTPUT_BINPATH}" ; echo */*))
  for platform in "${platforms[@]}"; do
    local platform_tag=${platform/\//-} # Replace a "/" for a "-"
    kube::log::status "Starting tarball: client $platform_tag"

    (
      local release_stage="${RELEASE_STAGE}/client/${platform_tag}/kubernetes"
      rm -rf "${release_stage}"
      mkdir -p "${release_stage}/client/bin"

      local client_bins=("${KUBE_CLIENT_BINARIES[@]}")
      if [[ "${platform%/*}" == "windows" ]]; then
        client_bins=("${KUBE_CLIENT_BINARIES_WIN[@]}")
      fi

      # This fancy expression will expand to prepend a path
      # (${LOCAL_OUTPUT_BINPATH}/${platform}/) to every item in the
      # KUBE_CLIENT_BINARIES array.
      cp "${client_bins[@]/#/${LOCAL_OUTPUT_BINPATH}/${platform}/}" \
        "${release_stage}/client/bin/"

      kube::release::clean_cruft

      local package_name="${RELEASE_TARS}/kubernetes-client-${platform_tag}.tar.gz"
      kube::release::create_tarball "${package_name}" "${release_stage}/.."
    ) &
  done

  kube::log::status "Waiting on tarballs"
  kube::util::wait-for-jobs || { kube::log::error "client tarball creation failed"; exit 1; }
}

# Package up all of the node binaries
function kube::release::package_node_tarballs() {
  local platform
  for platform in "${KUBE_NODE_PLATFORMS[@]}"; do
    local platform_tag=${platform/\//-} # Replace a "/" for a "-"
    local arch=$(basename "${platform}")
    kube::log::status "Building tarball: node $platform_tag"

    local release_stage="${RELEASE_STAGE}/node/${platform_tag}/kubernetes"
    rm -rf "${release_stage}"
    mkdir -p "${release_stage}/node/bin"

    local node_bins=("${KUBE_NODE_BINARIES[@]}")
    if [[ "${platform%/*}" == "windows" ]]; then
      node_bins=("${KUBE_NODE_BINARIES_WIN[@]}")
    fi
    # This fancy expression will expand to prepend a path
    # (${LOCAL_OUTPUT_BINPATH}/${platform}/) to every item in the
    # KUBE_NODE_BINARIES array.
    cp "${node_bins[@]/#/${LOCAL_OUTPUT_BINPATH}/${platform}/}" \
      "${release_stage}/node/bin/"

    # TODO: Docker images here
    # kube::release::create_docker_images_for_server "${release_stage}/server/bin" "${arch}"

    # Include the client binaries here too as they are useful debugging tools.
    local client_bins=("${KUBE_CLIENT_BINARIES[@]}")
    if [[ "${platform%/*}" == "windows" ]]; then
      client_bins=("${KUBE_CLIENT_BINARIES_WIN[@]}")
    fi
    cp "${client_bins[@]/#/${LOCAL_OUTPUT_BINPATH}/${platform}/}" \
      "${release_stage}/node/bin/"

    cp "${KUBE_ROOT}/Godeps/LICENSES" "${release_stage}/"

    cp "${RELEASE_TARS}/kubernetes-src.tar.gz" "${release_stage}/"

    kube::release::clean_cruft

    local package_name="${RELEASE_TARS}/kubernetes-node-${platform_tag}.tar.gz"
    kube::release::create_tarball "${package_name}" "${release_stage}/.."
  done
}

# Package up all of the server binaries in docker images
function kube::release::build_server_images() {
  # Clean out any old images
  rm -rf "${RELEASE_IMAGES}"
  local platform
  for platform in "${KUBE_SERVER_PLATFORMS[@]}"; do
    local platform_tag=${platform/\//-} # Replace a "/" for a "-"
    local arch=$(basename "${platform}")
    kube::log::status "Building images: $platform_tag"

    local release_stage="${RELEASE_STAGE}/server/${platform_tag}/kubernetes"
    rm -rf "${release_stage}"
    mkdir -p "${release_stage}/server/bin"
    mkdir -p "${release_stage}/addons"

    # This fancy expression will expand to prepend a path
    # (${LOCAL_OUTPUT_BINPATH}/${platform}/) to every item in the
    # KUBE_SERVER_IMAGE_BINARIES array.
    cp "${KUBE_SERVER_IMAGE_BINARIES[@]/#/${LOCAL_OUTPUT_BINPATH}/${platform}/}" \
      "${release_stage}/server/bin/"

    # if we are building hyperkube, we also need to copy that binary
    if [[ "${KUBE_BUILD_HYPERKUBE}" =~ [yY] ]]; then
      cp "${LOCAL_OUTPUT_BINPATH}/${platform}/hyperkube" "${release_stage}/server/bin"
    fi

    kube::release::create_docker_images_for_server "${release_stage}/server/bin" "${arch}"
  done
}

# Package up all of the server binaries
function kube::release::package_server_tarballs() {
  local platform
  for platform in "${KUBE_SERVER_PLATFORMS[@]}"; do
    local platform_tag=${platform/\//-} # Replace a "/" for a "-"
    local arch=$(basename "${platform}")
    kube::log::status "Building tarball: server $platform_tag"

    local release_stage="${RELEASE_STAGE}/server/${platform_tag}/kubernetes"
    rm -rf "${release_stage}"
    mkdir -p "${release_stage}/server/bin"
    mkdir -p "${release_stage}/addons"

    # This fancy expression will expand to prepend a path
    # (${LOCAL_OUTPUT_BINPATH}/${platform}/) to every item in the
    # KUBE_SERVER_BINARIES array.
    cp "${KUBE_SERVER_BINARIES[@]/#/${LOCAL_OUTPUT_BINPATH}/${platform}/}" \
      "${release_stage}/server/bin/"

    kube::release::create_docker_images_for_server "${release_stage}/server/bin" "${arch}"

    # Include the client binaries here too as they are useful debugging tools.
    local client_bins=("${KUBE_CLIENT_BINARIES[@]}")
    if [[ "${platform%/*}" == "windows" ]]; then
      client_bins=("${KUBE_CLIENT_BINARIES_WIN[@]}")
    fi
    cp "${client_bins[@]/#/${LOCAL_OUTPUT_BINPATH}/${platform}/}" \
      "${release_stage}/server/bin/"

    cp "${KUBE_ROOT}/Godeps/LICENSES" "${release_stage}/"

    cp "${RELEASE_TARS}/kubernetes-src.tar.gz" "${release_stage}/"

    kube::release::clean_cruft

    local package_name="${RELEASE_TARS}/kubernetes-server-${platform_tag}.tar.gz"
    kube::release::create_tarball "${package_name}" "${release_stage}/.."
  done
}

function kube::release::md5() {
  if which md5 >/dev/null 2>&1; then
    md5 -q "$1"
  else
    md5sum "$1" | awk '{ print $1 }'
  fi
}

function kube::release::sha1() {
  if which sha1sum >/dev/null 2>&1; then
    sha1sum "$1" | awk '{ print $1 }'
  else
    shasum -a1 "$1" | awk '{ print $1 }'
  fi
}

function kube::release::build_hyperkube_image() {
  local -r arch="$1"
  local -r registry="$2"
  local -r version="$3"
  local -r save_dir="${4-}"
  kube::log::status "Building hyperkube image for arch: ${arch}"
  ARCH="${arch}" REGISTRY="${registry}" VERSION="${version}" \
    make -C cluster/images/hyperkube/ build >/dev/null

  local hyperkube_tag="${registry}/hyperkube-${arch}:${version}"
  if [[ -n "${save_dir}" ]]; then
    "${DOCKER[@]}" save "${hyperkube_tag}" > "${save_dir}/hyperkube-${arch}.tar"
  fi
  if [[ -z "${KUBE_DOCKER_IMAGE_TAG-}" || -z "${KUBE_DOCKER_REGISTRY-}" ]]; then
    # not a release
    kube::log::status "Deleting hyperkube image ${hyperkube_tag}"
    "${DOCKER[@]}" rmi "${hyperkube_tag}" &>/dev/null || true
  fi
}

# This will take binaries that run on master and creates Docker images
# that wrap the binary in them. (One docker image per binary)
# Args:
#  $1 - binary_dir, the directory to save the tared images to.
#  $2 - arch, architecture for which we are building docker images.
function kube::release::create_docker_images_for_server() {
  # Create a sub-shell so that we don't pollute the outer environment
  (
    local binary_dir="$1"
    local arch="$2"
    local binary_name
    local binaries=($(kube::build::get_docker_wrapped_binaries "${arch}"))
    local images_dir="${RELEASE_IMAGES}/${arch}"
    mkdir -p "${images_dir}"

    local -r docker_registry="k8s.gcr.io"
    # TODO(thockin): Remove all traces of this after 1.11 release.
    # The following is the old non-indirected registry name.  To ease the
    # transition to the new name (above), we are double-tagging saved images.
    local -r deprecated_registry="gcr.io/google_containers"
    # Docker tags cannot contain '+'
    local docker_tag="${KUBE_GIT_VERSION/+/_}"
    if [[ -z "${docker_tag}" ]]; then
      kube::log::error "git version information missing; cannot create Docker tag"
      return 1
    fi

    for wrappable in "${binaries[@]}"; do

      local oldifs=$IFS
      IFS=","
      set $wrappable
      IFS=$oldifs

      local binary_name="$1"
      local base_image="$2"
      local docker_build_path="${binary_dir}/${binary_name}.dockerbuild"
      local docker_file_path="${docker_build_path}/Dockerfile"
      local binary_file_path="${binary_dir}/${binary_name}"
      local docker_image_tag="${docker_registry}"
      local deprecated_image_tag="${deprecated_registry}"
      if [[ ${arch} == "amd64" ]]; then
        # If we are building a amd64 docker image, preserve the original
        # image name
        docker_image_tag+="/${binary_name}:${docker_tag}"
        deprecated_image_tag+="/${binary_name}:${docker_tag}"
      else
        # If we are building a docker image for another architecture,
        # append the arch in the image tag
        docker_image_tag+="/${binary_name}-${arch}:${docker_tag}"
        deprecated_image_tag+="/${binary_name}-${arch}:${docker_tag}"
      fi


      kube::log::status "Starting docker build for image: ${binary_name}-${arch}"
      (
        rm -rf "${docker_build_path}"
        mkdir -p "${docker_build_path}"
        ln "${binary_dir}/${binary_name}" "${docker_build_path}/${binary_name}"
        printf " FROM ${base_image} \n ADD ${binary_name} /usr/local/bin/${binary_name}\n" > "${docker_file_path}"

        "${DOCKER[@]}" build --pull -q -t "${docker_image_tag}" "${docker_build_path}" >/dev/null
        "${DOCKER[@]}" tag "${docker_image_tag}" "${deprecated_image_tag}" >/dev/null
        "${DOCKER[@]}" save "${docker_image_tag}" "${deprecated_image_tag}" > "${binary_dir}/${binary_name}.tar"
        echo "${docker_tag}" > "${binary_dir}/${binary_name}.docker_tag"
        rm -rf "${docker_build_path}"
        ln "${binary_dir}/${binary_name}.tar" "${images_dir}/"

        # If we are building an official/alpha/beta release we want to keep
        # docker images and tag them appropriately.
        if [[ -n "${KUBE_DOCKER_IMAGE_TAG-}" && -n "${KUBE_DOCKER_REGISTRY-}" ]]; then
          local release_docker_image_tag="${KUBE_DOCKER_REGISTRY}/${binary_name}-${arch}:${KUBE_DOCKER_IMAGE_TAG}"
          # Only rmi and tag if name is different
          if [[ $docker_image_tag != $release_docker_image_tag ]]; then
            kube::log::status "Tagging docker image ${docker_image_tag} as ${release_docker_image_tag}"
            "${DOCKER[@]}" rmi "${release_docker_image_tag}" 2>/dev/null || true
            "${DOCKER[@]}" tag "${docker_image_tag}" "${release_docker_image_tag}" 2>/dev/null
          fi
        else
          # not a release
          kube::log::status "Deleting docker image ${docker_image_tag}"
          "${DOCKER[@]}" rmi "${docker_image_tag}" &>/dev/null || true
          "${DOCKER[@]}" rmi "${deprecated_image_tag}" &>/dev/null || true
        fi
      ) &
    done

    if [[ "${KUBE_BUILD_HYPERKUBE}" =~ [yY] ]]; then
      kube::release::build_hyperkube_image "${arch}" "${docker_registry}" \
        "${docker_tag}" "${images_dir}" &
    fi

    kube::util::wait-for-jobs || { kube::log::error "previous Docker build failed"; return 1; }
    kube::log::status "Docker builds done"
  )

}

# This will pack kube-system manifests files for distros such as COS.
function kube::release::package_kube_manifests_tarball() {
  kube::log::status "Building tarball: manifests"

  local src_dir="${KUBE_ROOT}/cluster/gce/manifests"

  local release_stage="${RELEASE_STAGE}/manifests/kubernetes"
  rm -rf "${release_stage}"

  local dst_dir="${release_stage}/gci-trusty"
  mkdir -p "${dst_dir}"
  cp "${src_dir}/kube-proxy.manifest" "${dst_dir}/"
  cp "${src_dir}/cluster-autoscaler.manifest" "${dst_dir}/"
  cp "${src_dir}/etcd.manifest" "${dst_dir}"
  cp "${src_dir}/kube-scheduler.manifest" "${dst_dir}"
  cp "${src_dir}/kms-plugin-container.manifest" "${dst_dir}"
  cp "${src_dir}/kube-apiserver.manifest" "${dst_dir}"
  cp "${src_dir}/abac-authz-policy.jsonl" "${dst_dir}"
  cp "${src_dir}/kube-controller-manager.manifest" "${dst_dir}"
  cp "${src_dir}/kube-addon-manager.yaml" "${dst_dir}"
  cp "${src_dir}/glbc.manifest" "${dst_dir}"
  cp "${src_dir}/e2e-image-puller.manifest" "${dst_dir}/"
  cp "${src_dir}/etcd-empty-dir-cleanup.yaml" "${dst_dir}/"
  local internal_manifest
  for internal_manifest in $(ls "${src_dir}" | grep "^internal-*"); do
    cp "${src_dir}/${internal_manifest}" "${dst_dir}"
  done
  cp "${KUBE_ROOT}/cluster/gce/gci/configure-helper.sh" "${dst_dir}/gci-configure-helper.sh"
  if [[ -e "${KUBE_ROOT}/cluster/gce/gci/gke-internal-configure-helper.sh" ]]; then
    cp "${KUBE_ROOT}/cluster/gce/gci/gke-internal-configure-helper.sh" "${dst_dir}/"
  fi
  cp "${KUBE_ROOT}/cluster/gce/gci/health-monitor.sh" "${dst_dir}/health-monitor.sh"
  local objects
  objects=$(cd "${KUBE_ROOT}/cluster/addons" && find . \( -name \*.yaml -or -name \*.yaml.in -or -name \*.json \) | grep -v demo)
  tar c -C "${KUBE_ROOT}/cluster/addons" ${objects} | tar x -C "${dst_dir}"
  # Merge GCE-specific addons with general purpose addons.
  local gce_objects
  gce_objects=$(cd "${KUBE_ROOT}/cluster/gce/addons" && find . \( -name \*.yaml -or -name \*.yaml.in -or -name \*.json \) \( -not -name \*demo\* \))
  if [[ -n "${gce_objects}" ]]; then
    tar c -C "${KUBE_ROOT}/cluster/gce/addons" ${gce_objects} | tar x -C "${dst_dir}"
  fi

  kube::release::clean_cruft

  local package_name="${RELEASE_TARS}/kubernetes-manifests.tar.gz"
  kube::release::create_tarball "${package_name}" "${release_stage}/.."
}

# This is the stuff you need to run tests from the binary distribution.
function kube::release::package_test_tarball() {
  kube::log::status "Building tarball: test"

  local release_stage="${RELEASE_STAGE}/test/kubernetes"
  rm -rf "${release_stage}"
  mkdir -p "${release_stage}"

  local platform
  for platform in "${KUBE_TEST_PLATFORMS[@]}"; do
    local test_bins=("${KUBE_TEST_BINARIES[@]}")
    if [[ "${platform%/*}" == "windows" ]]; then
      test_bins=("${KUBE_TEST_BINARIES_WIN[@]}")
    fi
    mkdir -p "${release_stage}/platforms/${platform}"
    cp "${test_bins[@]/#/${LOCAL_OUTPUT_BINPATH}/${platform}/}" \
      "${release_stage}/platforms/${platform}"
  done
  for platform in "${KUBE_TEST_SERVER_PLATFORMS[@]}"; do
    mkdir -p "${release_stage}/platforms/${platform}"
    cp "${KUBE_TEST_SERVER_BINARIES[@]/#/${LOCAL_OUTPUT_BINPATH}/${platform}/}" \
      "${release_stage}/platforms/${platform}"
  done

  # Add the test image files
  mkdir -p "${release_stage}/test/images"
  cp -fR "${KUBE_ROOT}/test/images" "${release_stage}/test/"
  tar c "${KUBE_TEST_PORTABLE[@]}" | tar x -C "${release_stage}"

  kube::release::clean_cruft

  local package_name="${RELEASE_TARS}/kubernetes-test.tar.gz"
  kube::release::create_tarball "${package_name}" "${release_stage}/.."
}

# This is all the platform-independent stuff you need to run/install kubernetes.
# Arch-specific binaries will need to be downloaded separately (possibly by
# using the bundled cluster/get-kube-binaries.sh script).
# Included in this tarball:
#   - Cluster spin up/down scripts and configs for various cloud providers
#   - Tarballs for manifest configs that are ready to be uploaded
#   - Examples (which may or may not still work)
#   - The remnants of the docs/ directory
function kube::release::package_final_tarball() {
  kube::log::status "Building tarball: final"

  # This isn't a "full" tarball anymore, but the release lib still expects
  # artifacts under "full/kubernetes/"
  local release_stage="${RELEASE_STAGE}/full/kubernetes"
  rm -rf "${release_stage}"
  mkdir -p "${release_stage}"

  mkdir -p "${release_stage}/client"
  cat <<EOF > "${release_stage}/client/README"
Client binaries are no longer included in the Kubernetes final tarball.

Run cluster/get-kube-binaries.sh to download client and server binaries.
EOF

  # We want everything in /cluster.
  cp -R "${KUBE_ROOT}/cluster" "${release_stage}/"

  mkdir -p "${release_stage}/server"
  cp "${RELEASE_TARS}/kubernetes-manifests.tar.gz" "${release_stage}/server/"
  cat <<EOF > "${release_stage}/server/README"
Server binary tarballs are no longer included in the Kubernetes final tarball.

Run cluster/get-kube-binaries.sh to download client and server binaries.
EOF

  # Include hack/lib as a dependency for the cluster/ scripts
  mkdir -p "${release_stage}/hack"
  cp -R "${KUBE_ROOT}/hack/lib" "${release_stage}/hack/"

  cp -R "${KUBE_ROOT}/docs" "${release_stage}/"
  cp "${KUBE_ROOT}/README.md" "${release_stage}/"
  cp "${KUBE_ROOT}/Godeps/LICENSES" "${release_stage}/"

  echo "${KUBE_GIT_VERSION}" > "${release_stage}/version"

  kube::release::clean_cruft

  local package_name="${RELEASE_TARS}/kubernetes.tar.gz"
  kube::release::create_tarball "${package_name}" "${release_stage}/.."
}

# Build a release tarball.  $1 is the output tar name.  $2 is the base directory
# of the files to be packaged.  This assumes that ${2}/kubernetes is what is
# being packaged.
function kube::release::create_tarball() {
  kube::build::ensure_tar

  local tarfile=$1
  local stagingdir=$2

  "${TAR}" czf "${tarfile}" -C "${stagingdir}" kubernetes --owner=0 --group=0
}