---
page_title: Docker Swarm
page_description: Swarm: a Docker-native clustering system
page_keywords: docker, swarm, clustering
---

# Docker Swarm: a Docker-native clustering system

Docker `swarm` helps you control a cluster of Docker hosts (known as nodes)
and expose them as a single "virtual" host.

The Docker `swarm` manager can be interacted with using the Docker API, which means
any tool which can communicate with a Docker Daemon using that API, can control
a Docker swarm transparently: dokku, fig, krane, flynn, deis, docker-ui, shipyard,
drone.io, Jenkins... and of course the Docker client itself.

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

## Installation

> **Note**: The only requirement for Swarm nodes is they all run the _same_ release
> Docker daemon (version `1.4.0` and later), configured to listen to a `tcp`
> port that the Swarm manager can access.

Docker `swarm` is currently only available as a single go binary on Linux. Download
it from [the latest release](https://github.com/docker/swarm/releases/latest) page
on GitHub.

For example:

```
	$ wget -O swarm https://github.com/docker/swarm/releases/download/v0.1.0-rc1/swarm-Linux-x86_64
	# OR
	$ curl -SsL https://github.com/docker/swarm/releases/download/v0.1.0-rc1/swarm-Linux-x86_64 > swarm
	$ chmod 755 swarm
	$ sudo cp swarm /usr/local/bin
```

## Nodes setup

Each swarm node will run a swarm node agent which will register the referenced
Docker daemon, and will then monitor it, updating the discovery backend to its
status.

The following example uses the Docker Hub based `token` discovery service:

```bash
# create a cluster
$ swarm create
6856663cdefdec325839a4b7e1de38e8 # <- this is your unique <cluster_id>

# For each of your nodes, start a swarm agent
#  the Docker daemon <node_ip> doesn't have to be public (eg. 192.168.0.X),
#  as long as the swarm manager can access it.
$ swarm join --addr=<node_ip:2375> token://<cluster_id>

# start the manager on any machine or your laptop
$ swarm manage -H tcp://<swarm_ip:swarm_port> token://<cluster_id>

# use the regular docker cli
$ docker -H tcp://<swarm_ip:swarm_port> info
$ docker -H tcp://<swarm_ip:swarm_port> run ...
$ docker -H tcp://<swarm_ip:swarm_port> ps
$ docker -H tcp://<swarm_ip:swarm_port> logs ...
...

# list nodes in your cluster
$ swarm list token://<cluster_id>
<node_ip:2375>
```

> **Note**: In order for the Swarm manager to be able to communicate with the node agent on
each node, they must listen to a common network interface. This can be achieved
by starting with the `-H` flag (e.g. `-H tcp://0.0.0.0:2375`).


## TLS

Swarm supports TLS authentication between the CLI and Swarm but also between
Swarm and the Docker nodes. _However_, all the Docker daemon certificates and client
certificates **must** be signed using the same CA-certificate.

In order to enable TLS for both client and server, the same command line options
as Docker can be specified:

`swarm manage --tlsverify --tlscacert=<CACERT> --tlscert=<CERT> --tlskey=<KEY> [...]`

Please refer to the [Docker documentation](https://docs.docker.com/articles/https/)
for more information on how to set up TLS authentication on Docker and generating
the certificates.

> **Note**: Swarm certificates must be generated with`extendedKeyUsage = clientAuth,serverAuth`.

## Discovery services

See the [Discovery service](../discovery) document for more information.

## Advanced Scheduling

See [filters](../scheduler/filter) and [strategies](../scheduler/strategy) to learn
more about advanced scheduling.