___
# Documentation
* [Basics](#basics)
* [Global configuration](#global)
* [File backend](#file)
* [API backend](#api)
* [Docker backend](#docker)
* [Mesos/Marathon backend](#marathon)
* [Consul backend](#consul)
## 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.
## 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"
```
## 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
```
## API backend
Træfik can be configured using a restful api.
To enable it:
```toml
[web]
address = ":8080"
```
* ```/```: provides a simple HTML frontend of Træfik
* ```/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
## 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
## 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
## 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"
```