Docker Machine vs RancherOS: What are the differences?

Introduction

Docker Machine and RancherOS are two popular containerization technologies used in the world of DevOps. While both serve the purpose of managing and deploying containers, they have some key differences that set them apart. In this comparison, we will explore these differences and highlight their unique characteristics.

1. Installation and Configuration: Docker Machine is a tool used to create and manage Docker hosts/machines. It can be installed on various operating systems and allows users to easily provision Docker Swarm clusters. On the other hand, RancherOS is a lightweight Linux distribution designed specifically for running Docker containers. It comes preconfigured with all the necessary components to run containers efficiently, eliminating the need for a separate base OS.

2. Operating System: Docker Machine can be installed on top of various operating systems, including Windows, macOS, and Linux. It provisions Docker hosts using existing infrastructure, such as virtual machines or cloud providers. RancherOS, on the other hand, serves as the underlying operating system for containers. It is a minimalist Linux distribution optimized for running containers, with a minimal attack surface and a small memory footprint.

3. Management and Orchestration: Docker Machine focuses on creating and managing individual Docker hosts, handling the lifecycle of virtual machines or cloud instances. It provides a simple command-line interface for managing Docker engines on multiple hosts. RancherOS, on the other hand, is built specifically for managing containerized environments at scale. It includes built-in orchestration capabilities using Rancher, which allows users to deploy and manage containers across multiple hosts.

4. Container Runtime: Docker Machine uses the Docker Engine as the container runtime, which provides a lightweight and portable runtime environment for containers. RancherOS, being an operating system itself, also uses Docker as the default container runtime. However, it provides additional flexibility by allowing users to switch to alternative container runtimes like containerd or rkt if desired.

5. System Architecture: Docker Machine is designed to work on top of existing infrastructure, utilizing virtual machines or cloud instances as Docker hosts. It provides a way to manage remote Docker engines from a local machine. RancherOS, on the other hand, follows a more integrated approach by combining the operating system and the container runtime into a single entity. It can be booted directly on bare-metal machines or launched as virtual machines on various hypervisors.

6. Security and Updates: Docker Machine focuses more on the management aspect of Docker hosts, leaving security and updates to be handled at the host level. It relies on the underlying host operating system for security measures and updates. RancherOS, being a dedicated container operating system, provides a hardened security model specifically designed for container environments. It offers automatic updates for the OS and provides enhanced isolation and protection for containers.

In summary, Docker Machine is a tool that manages Docker hosts on existing infrastructure, while RancherOS is a lightweight container operating system that provides a minimalistic and optimized environment for running containers. Docker Machine focuses on individual host management, while RancherOS is built for managing containers at scale, providing enhanced security and orchestration capabilities.