All posts for: Container security

In the previous article, I introduced readers to the world of nspawn containers. This article will expand on that introduction to nspawn and focus on a more advanced topic - running the Docker daemon in an nspawn container. I will describe how to prepare the environment and install Docker in an isolated setting. The example presented comes from my project, where the configuration included Jenkins responsible for building Docker images and running applications using docker-compose. Security issues forced me to seek alternative solutions, such as using an nspawn container.

In today’s era, where virtualization and containerization play a significant role in the architecture of IT systems, tools such as Docker and Kubernetes have gained considerable popularity among developers and system administrators. However, for Linux users, there is also a lesser-known but incredibly powerful alternative - systemd-nspawn. Often referred to as “chroot on steroids,” systemd-nspawn enables the creation of lightweight isolation spaces that can be used to run software in isolated containers with minimal overhead. In this article, we will explore how systemd-nspawn allows the creation and management of containers in Linux, its main advantages, and how it differs from the more traditional chroot approach and other popular container solutions. Additionally, we will go through the process of configuring containers to allow SSH login and running them as a system service.