traefik/docs/index.md

<p align="center">
<img src="img/traefik.logo.png" alt="Træfɪk" title="Træfɪk" />
</p>

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Træfɪk is a modern HTTP reverse proxy and load balancer made to deploy microservices with ease.
It supports several backends ([Docker](https://www.docker.com/), [Swarm](https://docs.docker.com/swarm), [Mesos/Marathon](https://mesosphere.github.io/marathon/), [Consul](https://www.consul.io/), [Etcd](https://coreos.com/etcd/), [Zookeeper](https://zookeeper.apache.org), [BoltDB](https://github.com/boltdb/bolt), Rest API, file...) to manage its configuration automatically and dynamically.

## Overview

Imagine that you have deployed a bunch of microservices on your infrastructure. You probably used a service registry (like etcd or consul) and/or an orchestrator (swarm, Mesos/Marathon) to manage all these services.
If you want your users to access some of your microservices from the Internet, you will have to use a reverse proxy and configure it using virtual hosts or prefix paths:

- domain `api.domain.com` will point the microservice `api` in your private network
- path `domain.com/web` will point the microservice `web` in your private network
- domain `backoffice.domain.com` will point the microservices `backoffice` in your private network, load-balancing between your multiple instances

But a microservices architecture is dynamic... Services are added, removed, killed or upgraded often, eventually several times a day.

Traditional reverse-proxies are not natively dynamic. You can't change their configuration and hot-reload easily.

Here enters Træfɪk.

![Architecture](img/architecture.png)

Træfɪk can listen to your service registry/orchestrator API, and knows each time a microservice is added, removed, killed or upgraded, and can generate its configuration automatically.
Routes to your services will be created instantly.

Run it and forget it!
  

## Demo

Here is a demo of Træfɪk using Docker backend, showing a load-balancing between two servers, hot reloading of configuration, and graceful shutdown.

[![asciicast](https://asciinema.org/a/4tcyde7riou5vxulo6my3mtko.png)](https://asciinema.org/a/4tcyde7riou5vxulo6my3mtko)

## Get it

### Binary

You can grab the latest binary from the [releases](https://github.com/containous/traefik/releases) page and just run it with the [sample configuration file](https://raw.githubusercontent.com/containous/traefik/master/traefik.sample.toml):

```shell
./traefik -c traefik.toml
```

### Docker

Using the tiny Docker image:

```shell
docker run -d -p 8080:8080 -p 80:80 -v $PWD/traefik.toml:/etc/traefik/traefik.toml traefik
```

## Test it

You can test Træfɪk easily using [Docker compose](https://docs.docker.com/compose), with this `docker-compose.yml` file:

```yaml
traefik:
  image: traefik
  command: --web --docker --docker.domain=docker.localhost --logLevel=DEBUG
  ports:
    - "80:80"
    - "8080:8080"
  volumes:
    - /var/run/docker.sock:/var/run/docker.sock
    - /dev/null:/traefik.toml

whoami1:
  image: emilevauge/whoami
  labels:
    - "traefik.backend=whoami"
    - "traefik.frontend.rule=Host:whoami.docker.localhost"

whoami2:
  image: emilevauge/whoami
  labels:
    - "traefik.backend=whoami"
    - "traefik.frontend.rule=Host:whoami.docker.localhost"
```

Then, start it:
    
```
docker-compose up -d
```

Finally, test load-balancing between the two servers `whoami1` and `whoami2`:

```bash
$ curl -H Host:whoami.docker.localhost http://127.0.0.1
Hostname: ef194d07634a
IP: 127.0.0.1
IP: ::1
IP: 172.17.0.4
IP: fe80::42:acff:fe11:4
GET / HTTP/1.1
Host: 172.17.0.4:80
User-Agent: curl/7.35.0
Accept: */*
Accept-Encoding: gzip
X-Forwarded-For: 172.17.0.1
X-Forwarded-Host: 172.17.0.4:80
X-Forwarded-Proto: http
X-Forwarded-Server: dbb60406010d

$ curl -H Host:whoami.docker.localhost http://127.0.0.1
Hostname: 6c3c5df0c79a
IP: 127.0.0.1
IP: ::1
IP: 172.17.0.3
IP: fe80::42:acff:fe11:3
GET / HTTP/1.1
Host: 172.17.0.3:80
User-Agent: curl/7.35.0
Accept: */*
Accept-Encoding: gzip
X-Forwarded-For: 172.17.0.1
X-Forwarded-Host: 172.17.0.3:80
X-Forwarded-Proto: http
X-Forwarded-Server: dbb60406010d
```