Automating container image migration from Amazon ECR to GitLab

This post details a CI/CD pipeline for automating the migration of container images from Amazon ECR to GitLab's Container Registry. It includes setting up read-only AWS IAM permissions, configuring GitLab CI/CD variables (AWS_ACCOUNT_ID, AWS_DEFAULT_REGION, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, BULK_MIGRATE), and a Docker-in-Docker pipeline script that discovers repositories, enumerates tags, and performs `docker pull`, `docker tag`, and `docker push` operations. Best practices for large migrations are also provided.