build_utils.sh

#!/usr/bin/env bash

# Functions to generate version numbers for this project

function version_tag() {
  git rev-parse --short=8 HEAD
}

# generate set of less specific versions, eg. given 1.2.3 will print 1.2.3,
# 1.2 and 1
function gen_versions()
{
  local version=$1
  echo "$version"
  while [[ $version = *.* ]]; do
    version=${version%.*}
    echo "$version"
  done
}

# Returns the machine architecture for the current platform.
# Takes into account the DOCKER_DEFAULT_PLATFORM environment variable.
get_machine_architecture() {
  local architecture
  if [[ -n "${DOCKER_DEFAULT_PLATFORM:-}" ]]; then
    # Take part after the slash (e.g. linux/amd64 -> amd64)
    architecture="${DOCKER_DEFAULT_PLATFORM##*/}"
  else
    architecture="$(uname -m)"
  fi

  case "$architecture" in
    x86_64 | amd64)
      echo "linux/amd64"
      ;;
    aarch64 | arm64)
      echo "linux/arm64"
      ;;
    *)
      echo "linux/amd64"
      ;;
  esac
}

# tag_and_publish tag source image1 image2 ...
function tag_and_push() {
  local tag="$1"; shift
  local source="$1"; shift
  local arch
  case "${ARCH:-}" in
    arm64) arch="linux/arm64" ;;
    amd64) arch="linux/amd64" ;;
    *)     arch="$(get_machine_architecture)" ;;
  esac

  for image in "$@"; do
    local target=$image:$tag
    echo "Tagging $source as $target and pushing..."
    docker tag "$source" "$target"
    docker push --platform "$arch" "$target"
  done
}

# prepare_manifest image tag
function prepare_manifest() {
  local image="$1"
  local tag="$2"

  docker pull --platform linux/amd64 "${image}:${tag}-amd64"
  docker pull --platform linux/arm64 "${image}:${tag}-arm64"

  docker manifest create \
    --insecure \
    "${image}:${tag}" \
    --amend "${image}:${tag}-amd64" \
    --amend "${image}:${tag}-arm64"

  docker manifest push --insecure "${image}:${tag}"

  # Because the bill of materials is created based on local docker images this is necessary in order to have
  # identical records in BOM files as previously, before multi-arch changes
  docker rmi "${image}:${tag}-amd64"
  docker rmi "${image}:${tag}-arm64"
  docker pull "${image}:${tag}"
}