---
title: "containerd"
description: "2 posts about containerd, summarised, each linking to the original."
---

# containerd
> 2 posts about containerd, summarised, each linking to the original.

## Articles

### [Docker without Docker](https://yomu.fyi/post/docker-without-docker.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Apr 8, 2021
- Type: Explainer

Fly.io explains how it accepts OCI container images while avoiding Docker at runtime, choosing Firecracker micro-VMs because Docker’s isolation is not strong enough for its high-density multitenant environment. It describes OCI images as ordered tarball layers, showing how registry authentication, manifests, architecture selection, blob downloads, and configuration data are enough to reconstruct a container filesystem and entrypoint. On the platform side, flyctl uses Docker’s client library to push images, while a custom Go repository server adds token-based authorization, repository rewriting, and handling for cross-repository blob mounts and registry state. Servers use containerd as a cache over an LVM2 thin pool, leases and copy-on-write snapshots to provision VM filesystems quickly, and a Rust init configures mounts, networking, DNS, SSH, and the entrypoint before Firecracker runs the workload.


### [The January 2021 Fly ChangeLog](https://yomu.fyi/post/the-january-2021-fly-changelog.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Jan 26, 2021
- Type: Announcement

The January 2021 Fly ChangeLog covers platform and flyctl changes from December 2020 through January 2021, focusing on private networking, VPN access, scaling, and infrastructure work. 6PN networking adds private communication and DNS-based app discovery over Fly's WireGuard mesh, while IPv6 WireGuard Peering provides tunnels into an organization; the new wireguard command creates, lists, and removes tunnels. Fly also made instance-count scaling the default model, separating it from autoscaling through scale and autoscale commands. Backend updates switched image pulling to containerd, improving subsequent boot times for larger images, added app lifecycle events to application logs, and made volume initialization lazy with encryption enabled by default. The listed flyctl releases also add volume, memory-scaling, region, completion, and WireGuard updates, alongside bug fixes.