Textbook of Linux

← Software

containerd

An industry-standard container runtime.

containerd is the runtime that Docker, Kubernetes (via cri-containerd), and several cloud providers run beneath the hood. It manages the complete container lifecycle — image pull from a registry, image storage, snapshot creation, container execution via runc, and container supervision — through a small gRPC API that other tools build on.

The project was originally extracted from Docker in 2016 to make it easier for the broader container ecosystem to share a common low-level runtime. It joined the Cloud Native Computing Foundation in 2017 and graduated as a top-level CNCF project in 2019. Kubernetes deprecated the older dockershim adapter in favour of direct CRI containerd integration, so most modern Kubernetes clusters run containerd directly.

containerd is one of those infrastructure projects that most users never interact with directly but that nonetheless powers a substantial fraction of the world's container workloads. AKS, EKS, GKE, IKS, OpenShift, and many other Kubernetes distributions ship containerd as the default runtime.

Debian/Ubuntu: sudo apt install containerd
Fedora/RHEL:   sudo dnf install containerd
Arch:          sudo pacman -S containerd