Simple script to migrate all images from ACR to an alternative registry

migrate-acr-registry.sh

#!/bin/bash

# This script migrates images from one Azure Container Registry (ACR) to another registry.
# Run this script in a bash shell with the Azure CLI installed and authenticated.
# Make sure containerd is installed and running.
# Usage: ./migrate-acr-registry.sh <acr_name> <target_registry_name> <target_registry_username> <target_registry_password>
# Primary intention is to migrate images from ACR to another registry including multiplatform images and all tags.

set -ex

# Take registry name from prompt or parameter
acr_name=$1
if [ -z "$acr_name" ]; then
  read -p "Enter the name of the ACR registry: " acr_name
fi

# Check if the ACR registry exists
if ! az acr show --name "$acr_name" &> /dev/null; then
  echo "ACR registry $acr_name does not exist."
  exit 1
fi

# get target registry name from prompt or parameter
target_registry_name=$2
if [ -z "$target_registry_name" ]; then
  read -p "Enter the name of the target registry: " target_registry_name
fi

# get target registry username and password from prompt or parameter
target_registry_username=$3
if [ -z "$target_registry_username" ]; then
  read -p "Enter the username for the target registry: " target_registry_username
fi
target_registry_password=$4 
if [ -z "$target_registry_password" ]; then
  read -sp "Enter the password for the target registry: " target_registry_password
  echo
fi

# Get fill ACR FQDN
acr_fqdn=$(az acr show --name "$acr_name" --query "loginServer" -o tsv)

# Print the ACR FQDN
echo "ACR FQDN: $acr_fqdn"

# Get ACR refresh token
acr_refresh_token=$(az acr login --name "$acr_name" --expose-token --output tsv --query accessToken)

# Get the list of repositories in the ACR
repositories=$(az acr repository list --name "$acr_name" --output tsv)

# Print the list of repositories
echo "Repositories in ACR $acr_name:"
for repo in $repositories; do
  echo "- $repo"
done

# Process tags for each repository
for repo in $repositories; do
  echo "Tags for repository $repo:"
  tags=$(az acr repository show-tags --name "$acr_name" --repository "$repo" --output tsv)
  for tag in $tags; do
    echo "  - $tag"

    # Pull the image from ACR using ctr all platforms
    echo "Pulling image $acr_fqdn/$repo:$tag"
    ctr image pull --all-platforms --all-metadata --refresh "$acr_refresh_token" "$acr_fqdn/$repo:$tag" || {
      echo "Failed to pull image $acr_fqdn/$repo:$tag"
      continue
    }
    
    # Tag the image for the target registry
    echo "Tagging image $acr_fqdn/$repo:$tag to $target_registry_name/$repo:$tag"
    ctr image tag --force "$acr_fqdn/$repo:$tag" "$target_registry_name/$repo:$tag" || {
      echo "Failed to tag image $acr_fqdn/$repo:$tag to $target_registry_name/$repo:$tag"
      continue
    }
    # Push the image to the target registry
    echo "Pushing image $target_registry_name/$repo:$tag"
    ctr image push --user "$target_registry_username:$target_registry_password" "$target_registry_name/$repo:$tag" || {
      echo "Failed to push image $target_registry_name/$repo:$tag"
      continue
    }
  done
done