Buildah vs containerd

Buildah is a free command-line tool for building OCI container images on Linux. It can create images from working containers, Dockerfiles, or Containerfiles, and can also build through commands and scripts without a build file. Output can use OCI format or the traditional upstream Docker image format. Builds can run without root privileges, and Buildah follows a fork-exec model rather than running as a daemon. Its commands create, mount, unmount, delete, and rename working containers, as well as create or delete images; users can also pull images from a specified location and push local images elsewhere. Buildah is based on a Go API that other tools can vendor, and Podman uses it for Dockerfile builds while remaining independently installable. Buildah requires a kernel with OverlayFS or fuse-overlayfs support; RHEL or CentOS requires version 7.4 or later. Installation guidance warns that short image names can be spoofed and recommends fully qualified names from trusted registries or pulling by digest. The project points users to tutorials, releases, and a mailing list for questions.

containerd is a free container runtime for managing a host’s container lifecycle. It handles image transfer and storage, execution, and supervision, and is designed to be embedded in a larger system rather than used directly by developers or end users. It supports OCI images and image push and pull operations, and uses runc by default while allowing other OCI-compliant runtimes. Its built-in CRI plugin can make it the container runtime for a Kubernetes cluster, and it supports registries compliant with the OCI Distribution Specification. The daemon is available for Linux and Windows. Network-interface management and image building are outside containerd’s first-class scope, so higher-level systems or tools handle those jobs. Its ctr command-line tool is intended for development and debugging, without a guarantee of a stable interface or a human-friendly experience. Users typically also need runc and CNI plugins. The plan is free; free plan available, with no free trial.