Bash script to push Hasura E.E control plane images to a private registry

migrate_images_to_private_registry.sh

#!/bin/bash
json_key=$(<example.json) # JSON access key
internal_repo='localhost:8000' # URL to private container registry

docker login -u _json_key --password "$json_key" https://gcr.io # log into GCR

image_list=(`helm template lux-2.0.8.tgz | grep "image:"`) # get raw list of images from Helm charts
ignore_value="image:" # value to parse downstream

names=$(printf "'%s'\n" "${image_list[@]/$ignore_value}" | grep -v "''" | tr -d \'\" | tr -d "\r" | sort -u | uniq) # Assign output to variable via Bash command substitution
SAVEIFS=$IFS   # Save current IFS (Internal Field Separator)
IFS=$'\n'      # Change IFS to newline char
names=($names) # split the `names` string into an array by the same name

for lux_image in ${names[@]};
do
    IFS='/'
    read -a image_name <<< "$lux_image" # parse image URL into components

    docker pull "$lux_image"
    docker tag "$lux_image" "$internal_repo/${image_name[2]}"
    docker push "$internal_repo/${image_name[2]}"

done

IFS=$SAVEIFS   # Restore original IFS