ECR
Definition
Elastic Container Registry (ECR) is an AWS service that simplifies the storage, management, and deployment of Docker container images in the cloud.
Use Cases
- Amazon: Storing and distributing container images for microservices running on Amazon EKS — Teams build Docker images in CI, push versioned images to private ECR repositories, and configure EKS node IAM roles (or IRSA) to pull images from ECR during deployments. Images are tagged per environment (e.g., commit SHA, semver) and promoted through pipelines. (Centralized image management with IAM-controlled access, faster and more consistent deployments across environments, and reduced operational overhead compared to self-managed registries.)
- Netflix: Managing container images for cloud-based services and deployment pipelines — Container images are built via automated CI workflows, stored in a managed registry, and deployed through automated delivery tooling. Access is controlled via cloud IAM and images are versioned to support rollbacks and progressive delivery. (Improved deployment repeatability and rollback capability through immutable, versioned images and automated delivery processes.)
Provider Equivalents
- AWS: Amazon Elastic Container Registry (ECR)
- Azure: Azure Container Registry (ACR)
- GCP: Artifact Registry
- OCI: OCI Container Registry (OCIR)
Frequently Asked Questions
- What's the difference between ECR and Docker Hub?
- ECR is a private (or public) AWS-managed registry that integrates with AWS IAM, VPC networking, and AWS services like EKS/ECS. Docker Hub is a public registry service (with private options) that’s not AWS-native. If you run workloads on AWS and want tight IAM-based access control and private network options, ECR is often simpler to operate.
- When should I use ECR?
- Use ECR when you deploy containers on AWS (ECS, EKS, Lambda container images, or EC2) and want a managed registry with AWS IAM permissions, encryption, lifecycle policies for cleanup, and optional image scanning. It’s especially useful for teams that need private repositories, controlled access, and automated CI/CD image promotion.
- How much does ECR cost?
- ECR pricing mainly depends on (1) storage used by your images and (2) data transfer when images are pulled. Costs can increase with large images, many retained tags, frequent pulls across regions/accounts, or pulls to the public internet. You can reduce cost by using lifecycle policies to delete old tags and by keeping images smaller.
Category: containers
Difficulty: intermediate
Related Terms
See Also