# Marathon Backend
Træfik can be configured to use Marathon as a backend configuration.
See also [Marathon user guide](/user-guide/marathon).
## Configuration
```toml
################################################################
# Mesos/Marathon configuration backend
################################################################
# Enable Marathon configuration backend.
[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
# Default: "http://127.0.0.1:8080"
#
endpoint = "http://127.0.0.1:8080"
# Enable watch Marathon changes.
#
# Optional
# Default: true
#
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"
# Override template version
# For advanced users :)
#
# Optional
# - "1": previous template version (must be used only with older custom templates, see "filename")
# - "2": current template version (must be used to force template version when "filename" is used)
#
# templateVersion = 2
# Expose Marathon apps by default in Traefik.
#
# Optional
# Default: true
#
# exposedByDefault = false
# Convert Marathon groups to subdomains.
# Default behavior: /foo/bar/myapp => foo-bar-myapp.{defaultDomain}
# with groupsAsSubDomains enabled: /foo/bar/myapp => myapp.bar.foo.{defaultDomain}
#
# Optional
# Default: false
#
# groupsAsSubDomains = true
# Enable compatibility with marathon-lb labels.
#
# Optional
# Default: false
#
# marathonLBCompatibility = true
# Enable filtering using Marathon constraints..
# If enabled, Traefik will read Marathon constraints, as defined in https://mesosphere.github.io/marathon/docs/constraints.html
# Each individual constraint will be treated as a verbatim compounded tag.
# i.e. "rack_id:CLUSTER:rack-1", with all constraint groups concatenated together using ":"
#
# Optional
# Default: false
#
# filterMarathonConstraints = true
# Enable Marathon basic authentication.
#
# Optional
#
# [marathon.basic]
# httpBasicAuthUser = "foo"
# httpBasicPassword = "bar"
# TLS client configuration. https://golang.org/pkg/crypto/tls/#Config
#
# Optional
#
# [marathon.TLS]
# CA = "/etc/ssl/ca.crt"
# Cert = "/etc/ssl/marathon.cert"
# Key = "/etc/ssl/marathon.key"
# insecureSkipVerify = true
# DCOSToken for DCOS environment.
# This will override the Authorization header.
#
# Optional
#
# dcosToken = "xxxxxx"
# Override DialerTimeout.
# Amount of time to allow the Marathon provider to wait to open a TCP connection
# to a Marathon master.
# Can be provided in a format supported by [time.ParseDuration](https://golang.org/pkg/time/#ParseDuration) or as raw
# values (digits).
# If no units are provided, the value is parsed assuming seconds.
#
# Optional
# Default: "60s"
#
# dialerTimeout = "60s"
# Set the TCP Keep Alive interval for the Marathon HTTP Client.
# Can be provided in a format supported by [time.ParseDuration](https://golang.org/pkg/time/#ParseDuration) or as raw
# values (digits).
# If no units are provided, the value is parsed assuming seconds.
#
# Optional
# Default: "10s"
#
# keepAlive = "10s"
# By default, a task's IP address (as returned by the Marathon API) is used as
# backend server if an IP-per-task configuration can be found; otherwise, the
# name of the host running the task is used.
# The latter behavior can be enforced by enabling this switch.
#
# Optional
# Default: false
#
# forceTaskHostname = true
# Applications may define readiness checks which are probed by Marathon during
# deployments periodically and the results exposed via the API.
# Enabling the following parameter causes Traefik to filter out tasks
# whose readiness checks have not succeeded.
# Note that the checks are only valid at deployment times.
# See the Marathon guide for details.
#
# Optional
# Default: false
#
# respectReadinessChecks = true
```
To enable constraints see [backend-specific constraints section](/configuration/commons/#backend-specific).
## Labels: overriding default behavior
Marathon labels may be used to dynamically change the routing and forwarding behavior.
They may be specified on one of two levels: Application or service.
### Application Level
The following labels can be defined on Marathon applications. They adjust the behavior for the entire application.
| Label | Description |
|------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `traefik.domain` | Default domain used for frontend rules. |
| `traefik.enable=false` | Disable this container in Træfik |
| `traefik.port=80` | Register this port. Useful when the container exposes multiples ports. |
| `traefik.portIndex=1` | Register port by index in the application's ports array. Useful when the application exposes multiple ports. |
| `traefik.protocol=https` | Override the default `http` protocol |
| `traefik.weight=10` | Assign this weight to the container |
| `traefik.backend=foo` | Give the name `foo` to the generated backend for this container. |
| `traefik.backend.buffering.maxRequestBodyBytes=0` | See [buffering](/configuration/commons/#buffering) section. |
| `traefik.backend.buffering.maxResponseBodyBytes=0` | See [buffering](/configuration/commons/#buffering) section. |
| `traefik.backend.buffering.memRequestBodyBytes=0` | See [buffering](/configuration/commons/#buffering) section. |
| `traefik.backend.buffering.memResponseBodyBytes=0` | See [buffering](/configuration/commons/#buffering) section. |
| `traefik.backend.buffering.retryExpression=EXPR` | See [buffering](/configuration/commons/#buffering) section. |
| `traefik.backend.circuitbreaker.expression=EXPR` | Create a [circuit breaker](/basics/#backends) to be used against the backend |
| `traefik.backend.healthcheck.path=/health` | Enable health check for the backend, hitting the container at `path`. |
| `traefik.backend.healthcheck.port=8080` | Allow to use a different port for the health check. |
| `traefik.backend.healthcheck.interval=1s` | Define the health check interval. (Default: 30s) |
| `traefik.backend.loadbalancer.method=drr` | Override the default `wrr` load balancer algorithm |
| `traefik.backend.loadbalancer.stickiness=true` | Enable backend sticky sessions |
| `traefik.backend.loadbalancer.stickiness.cookieName=NAME` | Manually set the cookie name for sticky sessions |
| `traefik.backend.loadbalancer.sticky=true` | Enable backend sticky sessions (DEPRECATED) |
| `traefik.backend.maxconn.amount=10` | Set a maximum number of connections to the backend.
Must be used in conjunction with the below label to take effect. |
| `traefik.backend.maxconn.extractorfunc=client.ip` | Set the function to be used against the request to determine what to limit maximum connections to the backend by.
Must be used in conjunction with the above label to take effect. |
| `traefik.frontend.auth.basic=EXPR` | Sets basic authentication for that frontend in CSV format: `User:Hash,User:Hash` |
| `traefik.frontend.entryPoints=http,https` | Assign this frontend to entry points `http` and `https`.
Overrides `defaultEntryPoints` |
| `traefik.frontend.errors..backend=NAME` | See [custom error pages](/configuration/commons/#custom-error-pages) section. |
| `traefik.frontend.errors..query=PATH` | See [custom error pages](/configuration/commons/#custom-error-pages) section. |
| `traefik.frontend.errors..status=RANGE` | See [custom error pages](/configuration/commons/#custom-error-pages) section. |
| `traefik.frontend.passHostHeader=true` | Forward client `Host` header to the backend. |
| `traefik.frontend.passTLSCert=true` | Forward TLS Client certificates to the backend. |
| `traefik.frontend.priority=10` | Override default frontend priority |
| `traefik.frontend.rateLimit.extractorFunc=EXP` | See [rate limiting](/configuration/commons/#rate-limiting) section. |
| `traefik.frontend.rateLimit.rateSet..period=6` | See [rate limiting](/configuration/commons/#rate-limiting) section. |
| `traefik.frontend.rateLimit.rateSet..average=6` | See [rate limiting](/configuration/commons/#rate-limiting) section. |
| `traefik.frontend.rateLimit.rateSet..burst=6` | See [rate limiting](/configuration/commons/#rate-limiting) section. |
| `traefik.frontend.redirect.entryPoint=https` | Enables Redirect to another entryPoint for that frontend (e.g. HTTPS) |
| `traefik.frontend.redirect.regex=^http://localhost/(.*)` | Redirect to another URL for that frontend.
Must be set with `traefik.frontend.redirect.replacement`. |
| `traefik.frontend.redirect.replacement=http://mydomain/$1` | Redirect to another URL for that frontend.
Must be set with `traefik.frontend.redirect.regex`. |
| `traefik.frontend.redirect.permanent=true` | Return 301 instead of 302. |
| `traefik.frontend.rule=EXPR` | Override the default frontend rule. Default: `Host:{sub_domain}.{domain}`. |
| `traefik.frontend.whiteList.sourceRange=RANGE` | List of IP-Ranges which are allowed to access.
An unset or empty list allows all Source-IPs to access. If one of the Net-Specifications are invalid, the whole list is invalid and allows all Source-IPs to access. |
| `traefik.frontend.whiteList.useXForwardedFor=true` | Use `X-Forwarded-For` header as valid source of IP for the white list. |
#### Custom Headers
| Label | Description |
|-------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `traefik.frontend.headers.customRequestHeaders=EXPR ` | Provides the container with custom request headers that will be appended to each request forwarded to the container.
Format: HEADER:value||HEADER2:value2 |
| `traefik.frontend.headers.customResponseHeaders=EXPR` | Appends the headers to each response returned by the container, before forwarding the response to the client.
Format: HEADER:value||HEADER2:value2 |
|
#### Security Headers
| Label | Description |
|----------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `traefik.frontend.headers.allowedHosts=EXPR` | Provides a list of allowed hosts that requests will be processed.
Format: `Host1,Host2` |
| `traefik.frontend.headers.hostsProxyHeaders=EXPR ` | Provides a list of headers that the proxied hostname may be stored.
Format: `HEADER1,HEADER2` |
| `traefik.frontend.headers.SSLRedirect=true` | Forces the frontend to redirect to SSL if a non-SSL request is sent. |
| `traefik.frontend.headers.SSLTemporaryRedirect=true` | Forces the frontend to redirect to SSL if a non-SSL request is sent, but by sending a 302 instead of a 301. |
| `traefik.frontend.headers.SSLHost=HOST` | This setting configures the hostname that redirects will be based on. Default is "", which is the same host as the request. |
| `traefik.frontend.headers.SSLProxyHeaders=EXPR` | Header combinations that would signify a proper SSL Request (Such as `X-Forwarded-For:https`).
Format: HEADER:value||HEADER2:value2 |
| `traefik.frontend.headers.STSSeconds=315360000` | Sets the max-age of the STS header. |
| `traefik.frontend.headers.STSIncludeSubdomains=true` | Adds the `IncludeSubdomains` section of the STS header. |
| `traefik.frontend.headers.STSPreload=true` | Adds the preload flag to the STS header. |
| `traefik.frontend.headers.forceSTSHeader=false` | Adds the STS header to non-SSL requests. |
| `traefik.frontend.headers.frameDeny=false` | Adds the `X-Frame-Options` header with the value of `DENY`. |
| `traefik.frontend.headers.customFrameOptionsValue=VALUE` | Overrides the `X-Frame-Options` header with the custom value. |
| `traefik.frontend.headers.contentTypeNosniff=true` | Adds the `X-Content-Type-Options` header with the value `nosniff`. |
| `traefik.frontend.headers.browserXSSFilter=true` | Adds the X-XSS-Protection header with the value `1; mode=block`. |
| `traefik.frontend.headers.customBrowserXSSValue=VALUE` | Set custom value for X-XSS-Protection header. This overrides the BrowserXssFilter option. |
| `traefik.frontend.headers.contentSecurityPolicy=VALUE` | Adds CSP Header with the custom value. |
| `traefik.frontend.headers.publicKey=VALUE` | Adds pinned HTST public key header. |
| `traefik.frontend.headers.referrerPolicy=VALUE` | Adds referrer policy header. |
| `traefik.frontend.headers.isDevelopment=false` | This will cause the `AllowedHosts`, `SSLRedirect`, and `STSSeconds`/`STSIncludeSubdomains` options to be ignored during development.
When deploying to production, be sure to set this to false. |
### Applications with Multiple Ports (segment labels)
Segment labels are used to define routes to an application exposing multiple ports.
A segment is a group of labels that apply to a port exposed by an application.
You can define as many segments as ports exposed in an application.
Segment labels override the default behavior.
| Label | Description |
|---------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------|
| `traefik..domain` | Default domain used for frontend rules. |
| `traefik..portIndex=1` | Create a service binding with frontend/backend using this port index. Overrides `traefik.portIndex`. |
| `traefik..port=PORT` | Overrides `traefik.port`. If several ports need to be exposed, the service labels could be used. |
| `traefik..protocol=http` | Overrides `traefik.protocol`. |
| `traefik..weight=10` | Assign this service weight. Overrides `traefik.weight`. |
| `traefik..frontend.auth.basic=EXPR` | Sets a Basic Auth for that frontend |
| `traefik..frontend.backend=BACKEND` | Assign this service frontend to `BACKEND`. Default is to assign to the service backend. |
| `traefik..frontend.entryPoints=https` | Overrides `traefik.frontend.entrypoints` |
| `traefik..frontend.errors..backend=NAME` | See [custom error pages](/configuration/commons/#custom-error-pages) section. |
| `traefik..frontend.errors..query=PATH` | See [custom error pages](/configuration/commons/#custom-error-pages) section. |
| `traefik..frontend.errors..status=RANGE` | See [custom error pages](/configuration/commons/#custom-error-pages) section. |
| `traefik..frontend.passHostHeader=true` | Overrides `traefik.frontend.passHostHeader`. |
| `traefik..frontend.passTLSCert=true` | Overrides `traefik.frontend.passTLSCert`. |
| `traefik..frontend.priority=10` | Overrides `traefik.frontend.priority`. |
| `traefik..frontend.rateLimit.extractorFunc=EXP` | See [rate limiting](/configuration/commons/#rate-limiting) section. |
| `traefik..frontend.rateLimit.rateSet..period=6` | See [rate limiting](/configuration/commons/#rate-limiting) section. |
| `traefik..frontend.rateLimit.rateSet..average=6` | See [rate limiting](/configuration/commons/#rate-limiting) section. |
| `traefik..frontend.rateLimit.rateSet..burst=6` | See [rate limiting](/configuration/commons/#rate-limiting) section. |
| `traefik..frontend.redirect.entryPoint=https` | Overrides `traefik.frontend.redirect.entryPoint`. |
| `traefik..frontend.redirect.regex=^http://localhost/(.*)` | Overrides `traefik.frontend.redirect.regex`. |
| `traefik..frontend.redirect.replacement=http://mydomain/$1` | Overrides `traefik.frontend.redirect.replacement`. |
| `traefik..frontend.redirect.permanent=true` | Return 301 instead of 302. |
| `traefik..frontend.rule=EXP` | Overrides `traefik.frontend.rule`. Default: `{service_name}.{sub_domain}.{domain}` |
| `traefik..frontend.whitelistSourceRange=RANGE` | Overrides `traefik.frontend.whitelistSourceRange`. |
| `traefik..frontend.whiteList.sourceRange=RANGE` | Overrides `traefik.frontend.whiteList.sourceRange`. |
| `traefik..frontend.whiteList.useXForwardedFor=true` | Use `X-Forwarded-For` header as valid source of IP for the white list. |
#### Custom Headers
| Label | Description |
|----------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `traefik..frontend.headers.customRequestHeaders=EXPR ` | Provides the container with custom request headers that will be appended to each request forwarded to the container.
Format: HEADER:value||HEADER2:value2 |
| `traefik..frontend.headers.customResponseHeaders=EXPR` | Appends the headers to each response returned by the container, before forwarding the response to the client.
Format: HEADER:value||HEADER2:value2 |
#### Security Headers
| Label | Description |
|-------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `traefik..frontend.headers.allowedHosts=EXPR` | Provides a list of allowed hosts that requests will be processed.
Format: `Host1,Host2` |
| `traefik..frontend.headers.hostsProxyHeaders=EXPR ` | Provides a list of headers that the proxied hostname may be stored.
Format: `HEADER1,HEADER2` |
| `traefik..frontend.headers.SSLRedirect=true` | Forces the frontend to redirect to SSL if a non-SSL request is sent. |
| `traefik..frontend.headers.SSLTemporaryRedirect=true` | Forces the frontend to redirect to SSL if a non-SSL request is sent, but by sending a 302 instead of a 301. |
| `traefik..frontend.headers.SSLHost=HOST` | This setting configures the hostname that redirects will be based on. Default is "", which is the same host as the request. |
| `traefik..frontend.headers.SSLProxyHeaders=EXPR` | Header combinations that would signify a proper SSL Request (Such as `X-Forwarded-For:https`).
Format: HEADER:value||HEADER2:value2 |
| `traefik..frontend.headers.STSSeconds=315360000` | Sets the max-age of the STS header. |
| `traefik..frontend.headers.STSIncludeSubdomains=true` | Adds the `IncludeSubdomains` section of the STS header. |
| `traefik..frontend.headers.STSPreload=true` | Adds the preload flag to the STS header. |
| `traefik..frontend.headers.forceSTSHeader=false` | Adds the STS header to non-SSL requests. |
| `traefik..frontend.headers.frameDeny=false` | Adds the `X-Frame-Options` header with the value of `DENY`. |
| `traefik..frontend.headers.customFrameOptionsValue=VALUE` | Overrides the `X-Frame-Options` header with the custom value. |
| `traefik..frontend.headers.contentTypeNosniff=true` | Adds the `X-Content-Type-Options` header with the value `nosniff`. |
| `traefik..frontend.headers.browserXSSFilter=true` | Adds the X-XSS-Protection header with the value `1; mode=block`. |
| `traefik..frontend.headers.customBrowserXSSValue=VALUE` | Set custom value for X-XSS-Protection header. This overrides the BrowserXssFilter option. |
| `traefik..frontend.headers.contentSecurityPolicy=VALUE` | Adds CSP Header with the custom value. |
| `traefik..frontend.headers.publicKey=VALUE` | Adds pinned HTST public key header. |
| `traefik..frontend.headers.referrerPolicy=VALUE` | Adds referrer policy header. |
| `traefik..frontend.headers.isDevelopment=false` | This will cause the `AllowedHosts`, `SSLRedirect`, and `STSSeconds`/`STSIncludeSubdomains` options to be ignored during development.
When deploying to production, be sure to set this to false. |