Buildah vs Enroot

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.

Enroot is a free, open-source Linux command-line utility that turns traditional container and operating-system images into unprivileged sandboxes. It is aimed at high-performance or virtualized environments where portability and reproducibility matter and additional isolation is not required. Enroot runs without a daemon and supports unprivileged multi-user use without a setuid binary. Linux user and mount namespaces preserve filesystem separation, while the project provides little to no isolation. The command line covers batch, bundle, create, exec, export, import, list, remove, and start operations. It imports known formats including Docker, with the README reporting a 3x to 5x speedup for large Docker-image imports. Built-in GPU support uses libnvidia-container, and hooks can add NVIDIA support or Mellanox host MOFED. Runtime settings come from enroot.conf or higher-priority environment variables. Standard and hardened package flavors are available.