Check if Docker Image with Tag Exists

check_docker_tag.sh

#!/bin/bash

# This script will check to see if a Docker image exists for a specific tag. 
# Taken from here, with love: https://www.reddit.com/r/docker/comments/4hwdma/check_if_an_image_tag_for_a_private_repo_exists/

TOKEN=$( curl -sSLd "username=${DOCKER_HUB_USERNAME}&password=${DOCKER_HUB_PASSWORD}" https://hub.docker.com/v2/users/login | jq -r ".token" )
curl -sH "Authorization: JWT $TOKEN" "https://hub.docker.com/v2/repositories/${DOCKER_REPO}/tags/${DOCKER_TAG}/" | jq .
#{
#    "name": "latest",
#   "id": 780668,
#    "repository": 295322,
#    "creator": 2215,
#    "last_updater": 2215,
#    "last_updated": "2016-04-28T03:45:35.148832Z",
#    "image_id": null,
#    "v2": true,
#    "platforms": []
#}