Which service provides a fully managed Docker container registry?

Amazon Elastic Container Registry (ECR) is the service that provides a fully managed Docker container registry. It allows developers to easily store, manage, and deploy Docker container images. By being fully managed, ECR takes care of the infrastructure needed to run a container registry, ensuring high availability, security, and scalability without requiring users to manage their own servers or storage solutions.

With ECR, users benefit from the integration with other AWS services such as Amazon Elastic Container Service (ECS) and Amazon Elastic Kubernetes Service (EKS), simplifying the workflow for deploying containerized applications. ECR also supports features like image versioning, lifecycle policies for cleaning up images, and fine-grained access control using AWS Identity and Access Management (IAM).

The other services mentioned serve different purposes: Amazon ECS is focused on running and managing containers, Amazon S3 is designed for object storage, and Amazon EC2 provides scalable computing resources. These options do not function as a container registry, which is specifically the role served by Amazon ECR.