Helper file for conversion of architectures and tags for docker buildx.

helper.sh

#!/bin/ash

# This file contains a few different helper methods
# for building multi-arch images with docker buildx.
# Most of the methods is to convert tags and architectures, but it
# might be updated to contain more later on.

#
# Convert a "standard" architecture name into the format that buildx
# is expecting.
#
# arguments:
# $1 - String - Architecture name in "standard" format (e.g., x86_64, aarch64 etc).
#
function convert_arch () {
  case "$1" in
    # AMD64: x86_64, amd64, x64,

    x86_64 | amd64 | x64)
      echo "linux/amd64"
      exit;;
    aarch64 | arm64 | arm64v8)
      echo "linux/arm64"
      exit;;
    armv6)
      echo "linux/arm/v6"
      exit;;
    armv7 | arm32v7 | arm32 | armhf)
      echo "linux/arm/v7"
      exit;;
    ppc64le | ppc64el)
      echo "linux/ppc64le"
      exit;;
    s390x)
      echo "linux/s390x"
      exit;;
    x86 | i386 | 386)
      echo "linux/386"
      exit;;
  esac
}

#
# Takes multiple architecture in "standard" format and echos them
# in the docker buildx expected format as a , seperated string.
#
# arguments:
# $@: - String[] - Architecture names as strings.
#
function arch_list () {
  for arc in "$@"; do
    echo -n "$(convert_arch "${arc}"),"
  done
}

#
# Takes a set of image names and tag names as comma seperated strings
# and converts it into a list of `-t <img_name>:<tag_name>` for each entry.
#
# arguments:
# $1 - String - Image names as a comma seperated string (e.g., "img1,img2").
# $2 - String - Tag names as a comma seperated string (e.g., "tag1,tag2").
#
function make_tags () {
  IMGS=$(echo "$1" | awk 'BEGIN{RS=","} {print}')
  TAGS=$(echo "$2" | awk 'BEGIN{RS=","} {print}')
  for tag in ${TAGS}; do
    for img in ${IMGS}; do
      echo -n "-t ${img}:${tag} "
    done
  done
}

#
# Takes a set of image names and tag names as comma seperated strings
# and converts it into a list of `<img_name>:<tag_name>` for each entry.
#
# arguments:
# $1 - String - Image names as a comma seperated string (e.g., "img1,img2").
# $2 - String - Tag names as a comma seperated string (e.g., "tag1,tag2").
#
function image_list () {
  IMGS=$(echo "$1" | awk 'BEGIN{RS=","} {print}')
  TAGS=$(echo "$2" | awk 'BEGIN{RS=","} {print}')
  for tag in ${TAGS}; do
    for img in ${IMGS}; do
      echo -n "${img}:${tag} "
    done
  done
}

#
# Simple function to allow adding multiple tags to a specific image.
#
# arguemtns:
# $1 - String   - Origin image.
# $@ - String[] - New image:tag to create.
#
function multi_tag () {
  ORIGIN=$1
  shift
  for tag in "$@"; do
    docker tag "${ORIGIN}" "${tag}"
    echo "${ORIGIN} ==> ${tag}"
  done
}

#
# Simple function to push multiple tags in one command.
#
# arguments:
# $@ - String[] - image:tag list to push.
#
function multi_push () {
  echo "Pushing the following tags: ${*}."
  for target in "$@"; do
    docker push "${target}"
  done
}

case "$1" in
  imagelist)
    shift
    image_list "$1" "$2"
    exit;;
  arch)
    shift
    convert_arch "$1"
    exit;;
  archlist)
    shift
    arch_list "${@}" | head -c -1
    exit;;
  taglist)
    shift
    make_tags "$1" "$2"
    exit;;
  multipush)
    shift
    multi_push "$@"
    exit;;
  multitag)
    shift
    multi_tag "$@"
    exit;;
  *)
    make_tags "$1" "$2"
    exit;;
esac

To add:

# Get dependencies required for a lib or executable.
scanelf --needed --nobanner --format '%n#p' $1 | tr ',' '\n' | sort -u | awk 'system("[ -e /usr/lib/" $1 " ]") == 0 { next } { print "so:" $1 }'