Under the hood: Lazy Loading Container Images with Seekable OCI and AWS Fargate

AWS Fargate, a serverless compute engine for containerized workloads, now supports lazy loading container images that have been indexed using Seekable OCI (SOCI). Lazy loading container images with SOCI reduces the time taken to launch Amazon Elastic Container Service (Amazon ECS) Tasks on AWS Fargate. Donnie Prakoso’s launch post provides details on how to get started with AWS Fargate and SOCI, therefore is recommended before reading this post.

In this post, we’ll dive into SOCI and how it can index a container image without modifying its contents or requiring a change to existing tools or workflows. We will discuss the SOCI snapshotter, a remote containerd snapshotter that leverages SOCI Indexes to lazy load container images. And finally, we will cover some of the caveats when using SOCI on AWS Fargate.

How does Seekable OCI work?

In containerd the component that manages the container’s filesystem is called a snapshotter. The default snapshotter, overlayfs, pulls and decompresses the …