docker-hub-tags-retrieval

dockerhub-tags.sh

#!/usr/bin/env bash

set -fue

[ "${DEBUG:-"NO"}" = "YES" ] && set -x

_ZIP=0
_DOCKERFILE=0

case "${1:-""}" in
  "-m") # zip image name with tags
      _ZIP=1
      shift
      ;;
  "-d") # generate a fake Dockerfile
      _DOCKERFILE=1
      _ZIP=1
      shift
      ;;
esac

if [ "${1:-""}" = "" ]; then
  (>&2 echo "Usage: ${0} [repo/]image") && exit 1
fi

# Full repo/image was supplied
if [[ "${1}" = *"/"* ]]; then
  name="${1}"

# Only image was supplied, default to library/image
else
  name="library/${1}"
fi

results=$(curl --silent "https://registry.hub.docker.com/v2/repositories/${name}/tags/?page=1" 2>/dev/null | jq -r '."results"[]["name"]' 2>/dev/null)

if [ -z "${results}" ]; then
  (>&2 echo "Could not retrieve any data for image ${name}") && exit 2
fi

sorted=$(echo "${results}" | sort)
output=$sorted

if [ $_ZIP -eq 1 ]; then
  zipped=$(
    echo "${sorted}" | awk -v imagename="${name}" '{print imagename":"$1}'
  )
  output=$zipped
else
  zipped=""
fi

if [ $_DOCKERFILE -eq 1 ]; then
  _build_data=$(
    echo "${zipped}" | awk '{sum+=1}; {print "FROM",$1,"as stage"sum}'
  )
  output=$_build_data
fi

printf "%s\n" "${output}"