Docker Images Without Docker -- A Practical Guide

Docker's reliance on root access for building images poses security concerns, prompting exploration of alternatives like Buildah, Podman, and Kaniko, which offer varying benefits and integration capabilities. Docker's architecture involves a Dockerfile to specify container images, with the Docker Daemon requiring root privileges to manage containers and images, thus posing security risks if a process escapes the container. Buildah and Podman, complementary tools, allow for building and managing OCI-compatible container images without a Docker daemon, with Buildah focusing on image creation and Podman on managing the container lifecycle. Conversely, Kaniko, an open-source tool supported by Google, enables building container images without root access, often within a Kubernetes cluster, making it a suitable alternative for Kubernetes users. While Docker is user-friendly, integrating alternatives depends on specific use cases, with Kaniko fitting well into Kubernetes environments and Buildah and Podman serving as direct Docker replacements for other scenarios.