Swarm: a Docker-native clustering system

Docker Swarm is native clustering for Docker. It turns a pool of Docker hosts into a single, virtual host.

Swarm Disambiguation

Docker Swarm standalone: This project. A native clustering system for Docker. It turns a pool of Docker hosts into a single, virtual host using an API proxy system. See Docker Swarm overview. It is Docker's first container orchestration project that began in 2014. Combined with Docker Compose, it's a very convenient tool to schedule containers. Its flexibility and simplicity make it easy to integrate with existing IT infrastructure. Many companies and users have deployed Docker Swarm standalone for production and experimental projects. Docker does not currently have a plan to deprecate Docker Swarm. The Docker API is backward compatible so Docker Swarm will continue to work with future Docker Engine versions.

Swarmkit: Cluster management and orchestration features in Docker Engine 1.12 or later. When Swarmkit is enabled we call Docker Engine running in swarm mode. See the feature list: Swarm mode overview. This project focuses on micro-service architecture. It supports service reconciliation, load balancing, service discovery, built-in certificate rotation, etc. Swarm mode is Docker's response to the community's request to simplify service orchestration.

While the 2 projects may accomplish similar tasks, they work on different levels in terms of service architecture. Users can choose which one is more suitable for their workload. If you're in doubt, Docker recommends that you try Docker 1.12 and later with built-in swarm mode.

Docker Swarm standalone

Swarm serves the standard Docker API, so any tool which already communicates with a Docker daemon can use Swarm to transparently scale to multiple hosts: Dokku, Compose, Krane, Flynn, Deis, DockerUI, Shipyard, Drone, Jenkins... and, of course, the Docker client itself.

Like other Docker projects, Swarm follows the "batteries included but removable" principle. It ships with a set of simple scheduling backends out of the box, and as initial development settles, an API will be developed to enable pluggable backends. The goal is to provide a smooth out-of-the-box experience for simple use cases, and allow swapping in more powerful backends, like Mesos, for large scale production deployments.

Installation for Swarm Users

For instructions on using Swarm in your dev, test or production environment, refer to the Docker Swarm documentation on docs.docker.com.

Building Swarm from Source

To compile Swarm from source code, refer to the instructions in CONTRIBUTING.md

Participating

You can contribute to Docker Swarm in several different ways:

• If you have comments, questions, or want to use your knowledge to help others, come join the conversation on IRC. You can reach us at #docker-swarm on Freenode.

• To report a problem or request a feature, please file an issue.

• Of course, we welcome pull requests and patches. Setting up a local Swarm development environment and submitting PRs is described here.

Finally, if you want to see what we have for the future and learn more about our release cycles, all this information is detailed on the wiki

Copyright and license

Copyright © 2014-2016 Docker, Inc. All rights reserved, except as follows. Code is released under the Apache 2.0 license. The README.md file, and files in the "docs" folder are licensed under the Creative Commons Attribution 4.0 International License under the terms and conditions set forth in the file "LICENSE.docs". You may obtain a duplicate copy of the same license, titled CC-BY-SA-4.0, at http://creativecommons.org/licenses/by/4.0/.