Mirror a Docker Trusted Registry (DTR) to another registry

mirror-docker-registries.sh

#!/bin/bash

read -p "Registry to clone from: " pull_registry
read -p "Username for $pull_registry: " user
read -s -p "Password for $pull_registry: " password
echo
read -p "Registry to clone onto: " push_registry

echo Querying $pull_registry...

[ -f list.txt ] && rm list.txt

for repo in $(curl -s -X GET \
  -H "Accept: application/json" \
  --user "$user:$password" \
  https://$pull_registry/api/v0/repositories | \
  jq -r '.repositories[] | [.namespace, .name] | join("/")')
do
  for tag in $(curl -s -X GET \
    -H "Accept: application/json" \
    --user "$user:$password" \
    https://$pull_registry/api/v0/repositories/$repo/tags | \
    jq -r '.tags[] | .name')
    do
      echo $repo:$tag >> list.txt
    done
done

while read slug; do
  set -x
  docker pull $pull_registry/$slug
  set +x
done < list.txt

while read slug; do
  set -x
  docker tag $pull_registry/$slug $push_registry/$slug
  set +x
done < list.txt

while read slug; do
  set -x
  docker push $push_registry/$slug
  set +x
done < list.txt

[ -f list.txt ] && rm list.txt