function to get docker registry versions

docker_reg_image_version

# Dump all docker registry image versions
docker_reg_image_versions () {
  if [ -z $1 ]; then
    echo "Pass registry hostname as argument."
  else
    reg="$1"
    read -p "$reg username: " user
    read -s -p "$reg password: " pass
    echo ""
    for i in $(curl -k -s -X GET "https://$reg/v2/_catalog" \
                -u "$user:$pass" -H "Accept: application/json" | \
                jq '.|.repositories[]' | cut -d'"' -f2); do
      curl -k -s -X GET "https://$reg/v2/$i/tags/list" \
        -u "$user:$pass" | jq .
    done
  fi
}