# Rancher Backend
Træfik can be configured to use Rancher as a backend configuration.
## Global Configuration
```toml
################################################################
# Rancher configuration backend
################################################################
# Enable Rancher configuration backend.
[rancher]
# Default domain used.
# Can be overridden by setting the "traefik.domain" label on an service.
#
# Required
#
domain = "rancher.localhost"
# Enable watch Rancher changes.
#
# Optional
# Default: true
#
watch = true
# Polling interval (in seconds).
#
# Optional
# Default: 15
#
refreshSeconds = 15
# Expose Rancher services by default in Traefik.
#
# Optional
# Default: true
#
exposedByDefault = false
# Filter services with unhealthy states and inactive states.
#
# Optional
# Default: false
#
enableServiceHealthFilter = true
```
To enable constraints see [backend-specific constraints section](/configuration/commons/#backend-specific).
## Rancher Metadata Service
```toml
# Enable Rancher metadata service configuration backend instead of the API
# configuration backend.
#
# Optional
# Default: false
#
[rancher.metadata]
# Poll the Rancher metadata service for changes every `rancher.RefreshSeconds`.
# NOTE: this is less accurate than the default long polling technique which
# will provide near instantaneous updates to Traefik
#
# Optional
# Default: false
#
intervalPoll = true
# Prefix used for accessing the Rancher metadata service.
#
# Optional
# Default: "/latest"
#
prefix = "/2016-07-29"
```
## Rancher API
```toml
# Enable Rancher API configuration backend.
#
# Optional
# Default: true
#
[rancher.api]
# Endpoint to use when connecting to the Rancher API.
#
# Required
endpoint = "http://rancherserver.example.com/v1"
# AccessKey to use when connecting to the Rancher API.
#
# Required
accessKey = "XXXXXXXXXXXXXXXXXXXX"
# SecretKey to use when connecting to the Rancher API.
#
# Required
secretKey = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
```
!!! note
If Traefik needs access to the Rancher API, you need to set the `endpoint`, `accesskey` and `secretkey` parameters.
To enable Traefik to fetch information about the Environment it's deployed in only, you need to create an `Environment API Key`.
This can be found within the API Key advanced options.
Add these labels to traefik docker deployment to autogenerated these values:
```
io.rancher.container.agent.role: environment
io.rancher.container.create_agent: true
```
## Labels: overriding default behaviour
Labels can be used on task containers to override default behaviour:
| Label | Description |
|------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `traefik.enable=false` | Disable this container in Træfik |
| `traefik.port=80` | Register this port. Useful when the container exposes multiples 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. |
| `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.loadbalancer.swarm=true` | Use Swarm's inbuilt load balancer (only relevant under Swarm Mode). |
| `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:{service_name}.{stack_name}.{domain}`. |
| `traefik.frontend.whitelistSourceRange=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. |
### 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.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. |