traefik/docs/index.md

![Træfɪk](http://traefik.github.io/traefik.logo.svg "Træfɪk")
___


# <a id="top"></a> Documentation

* [Basics](#basics)
* [Global configuration](#global)
* [File backend](#file)
* [API backend](#api)
* [Docker backend](#docker)
* [Mesos/Marathon backend](#marathon)
* [Consul backend](#consul)


## <a id="basics"></a> Basics


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

Basically, Træfɪk is a http router, which sends traffic from frontends to http backends, following rules you have configured.

### Frontends

Frontends can be defined using the following rules:

 * ```Headers```: Headers adds a matcher for request header values. It accepts a sequence of key/value pairs to be matched. For example: ```application/json```
 * ```HeadersRegexp```: Regular expressions can be used with headers as well. It accepts a sequence of key/value pairs, where the value has regex support. For example: ```application/(text|json)```
 * ```Host```: Host adds a matcher for the URL host. It accepts a template with zero or more URL variables enclosed by {}. Variables can define an optional regexp pattern to be matched: ```www.traefik.io```, ```{subdomain:[a-z]+}.traefik.io```
 * ```Methods```: Methods adds a matcher for HTTP methods. It accepts a sequence of one or more methods to be matched, e.g.: ```GET```, ```POST```, ```PUT```
 * ```Path```: Path adds a matcher for the URL path. It accepts a template with zero or more URL variables enclosed by {}. The template must start with a "/". For exemple ```/products/``` ```/articles/{category}/{id:[0-9]+}```
 * ```PathPrefix```: PathPrefix adds a matcher for the URL path prefix. This matches if the given template is a prefix of the full URL path.


 A frontend is a set of rules that forwards the incoming http traffic to a backend.

### HTTP Backends

A backend is responsible to load-balance the traffic coming from one or more frontends to a set of http servers.
Various types of load-balancing is supported:

* Weighted round robin
* Rebalancer: increases weights on servers that perform better than others. It also rolls back to original weights if the servers have changed.

A circuit breaker can also be applied to a backend, preventing high loads on failing servers.

## <a id="global"></a> Global configuration

```toml
# traefik.toml
################################################################
# Global configuration
################################################################

# Reverse proxy port
#
# Optional
# Default: ":80"
#
# port = ":80"

# Timeout in seconds.
# Duration to give active requests a chance to finish during hot-reloads
#
# Optional
# Default: 10
#
# graceTimeOut = 10

# Traefik logs file
#
# Optional
#
# traefikLogsFile = "log/traefik.log"

# Traefik log to standard output
#
# Optional
# Default: true
#
# traefikLogsStdout = true

# Access logs file
#
# Optional
#
# accessLogsFile = "log/access.log"

# Log level
#
# Optional
# Default: "ERROR"
#
# logLevel = "ERROR"

# SSL certificate and key used
#
# Optional
#
# CertFile = "traefik.crt"
# KeyFile = "traefik.key"
```


## <a id="file"></a> File backend

Like any other reverse proxy, Træfɪk can be configured with a file. You have two choices:

* simply add your configuration at the end of the global configuration file ```traefik.toml``` :

```toml
# traefik.toml
port = ":80"
graceTimeOut = 10
logLevel = "DEBUG"
traefikLogsStdout = true

[file]

# rules
[backends]
  [backends.backend1]
    [backends.backend1.servers.server1]
    url = "http://172.17.0.2:80"
    weight = 10
    [backends.backend1.servers.server2]
    url = "http://172.17.0.3:80"
    weight = 1
  [backends.backend2]
    [backends.backend2.servers.server1]
    url = "http://172.17.0.4:80"
    weight = 1

 [frontends]
   [frontends.frontend1]
   backend = "backend2"
     [frontends.frontend1.routes.test_1]
     rule = "Host"
     value = "test.localhost"
   [frontends.frontend2]
   backend = "backend1"
     [frontends.frontend2.routes.test_2]
     rule = "Path"
     value = "/test"

```

* or put your rules in a separate file, for example ```rules.tml```:

```toml
# traefik.toml
port = ":80"
graceTimeOut = 10
logLevel = "DEBUG"
traefikLogsStdout = true

[file]
filename = "rules.toml"
```

```toml
# rules.toml
[backends]
  [backends.backend1]
    [backends.backend1.servers.server1]
    url = "http://172.17.0.2:80"
    weight = 10
    [backends.backend1.servers.server2]
    url = "http://172.17.0.3:80"
    weight = 1
  [backends.backend2]
    [backends.backend2.servers.server1]
    url = "http://172.17.0.4:80"
    weight = 1

[frontends]
  [frontends.frontend1]
  backend = "backend2"
    [frontends.frontend1.routes.test_1]
    rule = "Host"
    value = "test.localhost"
  [frontends.frontend2]
  backend = "backend1"
    [frontends.frontend2.routes.test_2]
    rule = "Path"
    value = "/test"
```

If you want Træfɪk to watch file changes automatically, just add:

```toml
[file]
watch = true
```

## <a id="api"></a> API backend

Træfik can be configured using a restful api.
To enable it:

```toml
[web]
address = ":8080"
```
* ```/```: provides a simple HTML frontend of Træfik

![HTML frontend](img/web.frontend.png)

* ```/health```: ```GET``` json metrics

```sh
$ curl -s "http://localhost:8080/health" | jq .
{
  "average_response_time_sec": 0,
  "average_response_time": "0",
  "total_response_time_sec": 0,
  "total_response_time": "0",
  "total_count": 0,
  "pid": 12861,
  "uptime": "7m12.80607635s",
  "uptime_sec": 432.80607635,
  "time": "2015-09-22 10:25:16.448023473 +0200 CEST",
  "unixtime": 1442910316,
  "status_code_count": {},
  "total_status_code_count": {},
  "count": 0
}
```

* ```/api```: ```GET``` or ```PUT``` a configuration

```sh
$ curl -s "http://localhost:8082/api" | jq .
{
  "Frontends": {
    "frontend-traefik": {
      "Routes": {
        "route-host-traefik": {
          "Value": "traefik.docker.localhost",
          "Rule": "Host"
        }
      },
      "Backend": "backend-test2"
    },
    "frontend-test": {
      "Routes": {
        "route-host-test": {
          "Value": "test.docker.localhost",
          "Rule": "Host"
        }
      },
      "Backend": "backend-test1"
    }
  },
  "Backends": {
    "backend-test2": {
      "Servers": {
        "server-stoic_brattain": {
          "Weight": 0,
          "Url": "http://172.17.0.8:80"
        },
        "server-jovial_khorana": {
          "Weight": 0,
          "Url": "http://172.17.0.12:80"
        },
        "server-jovial_franklin": {
          "Weight": 0,
          "Url": "http://172.17.0.11:80"
        },
        "server-elegant_panini": {
          "Weight": 0,
          "Url": "http://172.17.0.9:80"
        },
        "server-adoring_elion": {
          "Weight": 0,
          "Url": "http://172.17.0.10:80"
        }
      }
    },
    "backend-test1": {
      "Servers": {
        "server-trusting_wozniak": {
          "Weight": 0,
          "Url": "http://172.17.0.5:80"
        },
        "server-sharp_jang": {
          "Weight": 0,
          "Url": "http://172.17.0.7:80"
        },
        "server-dreamy_feynman": {
          "Weight": 0,
          "Url": "http://172.17.0.6:80"
        }
      }
    }
  }
}

```

* ```/api/backends```: ```GET``` backends
* ```/api/backends/{backend}```: ```GET``` a backend
* ```/api/backends/{backend}/servers```: ```GET``` servers in a backend
* ```/api/backends/{backend}/servers/{server}```: ```GET``` a server in a backend
* ```/api/frontends```: ```GET``` frontends
* ```/api/frontends/{frontend}```: ```GET``` a frontend


## <a id="docker"></a> Docker backend

Træfɪk can be configured to use Docker as a backend configuration:

```toml
################################################################
# Docker configuration backend
################################################################

# Enable Docker configuration backend
#
# Optional
#
[docker]

# Docker server endpoint. Can be a tcp or a unix socket endpoint.
#
# Required
#
endpoint = "unix:///var/run/docker.sock"

# Default domain used.
# Can be overridden by setting the "traefik.domain" label on a container.
#
# Required
#
domain = "docker.localhost"

# Enable watch docker changes
#
# Optional
#
watch = true

# Override default configuration template. For advanced users :)
#
# Optional
#
# filename = "docker.tmpl"
```

Labels can be used on containers to override default behaviour:

* ```traefik.backend=foo```: assign the container to ```foo``` backend
* ```traefik.port=80```: register this port. Useful when the container exposes multiples ports.
* ```traefik.weight=10```: assign this weight to the container
* ```traefik.enable=false```: disable this container in Træfɪk

## <a id="marathon"></a> Marathon backend

Træfɪk can be configured to use Marathon as a backend configuration:


```toml
################################################################
# Mesos/Marathon configuration backend
################################################################

# Enable Marathon configuration backend
#
# Optional
#
[marathon]

# Marathon server endpoint.
# You can also specify multiple endpoint for Marathon:
# endpoint := "http://10.241.1.71:8080,10.241.1.72:8080,10.241.1.73:8080"
#
# Required
#
endpoint = "http://127.0.0.1:8080"

# Network interface used to call Marathon web services
# Optional
# Default: "eth0"
#
# networkInterface = "eth0"

# Enable watch Marathon changes
#
# Optional
#
watch = true

# Default domain used.
# Can be overridden by setting the "traefik.domain" label on an application.
#
# Required
#
domain = "marathon.localhost"

# Override default configuration template. For advanced users :)
#
# Optional
#
# filename = "marathon.tmpl"
```

Labels can be used on containers to override default behaviour:

* ```traefik.backend=foo```: assign the application to ```foo``` backend
* ```traefik.port=80```: register this port. Useful when the application exposes multiples ports.
* ```traefik.weight=10```: assign this weight to the application
* ```traefik.enable=false```: disable this application in Træfɪk

## <a id="consul"></a> Consul backend

Træfɪk can be configured to use Consul as a backend configuration:

```toml
################################################################
# Consul KV configuration backend
################################################################

# Enable Consul KV configuration backend
#
# Optional
#
[consul]

# Consul server endpoint
#
# Required
#
endpoint = "http://127.0.0.1:8500"

# Enable watch Consul changes
#
# Optional
#
watch = true

# Prefix used for KV store.
#
# Optional
#
prefix = "traefik"

# Override default configuration template. For advanced users :)
#
# Optional
#
# filename = "consul.tmpl"
```