When deployed into Kubernetes, Traefik will read the environment variables `KUBERNETES_SERVICE_HOST` and `KUBERNETES_SERVICE_PORT` to construct the endpoint.
The access token will be looked up in `/var/run/secrets/kubernetes.io/serviceaccount/token` and the SSL CA certificate in `/var/run/secrets/kubernetes.io/serviceaccount/ca.crt`.
Both are provided mounted automatically when deployed inside Kubernetes.
Specifically, it may be set to the URL used by `kubectl proxy` to connect to a Kubernetes cluster using the granted autentication and authorization of the associated kubeconfig.
### TLS communication between Traefik and backend pods
Traefik automatically requests endpoint information based on the service provided in the ingress spec.
Although traefik will connect directly to the endpoints (pods), it still checks the service port to see if TLS communication is required.
If the service port defined in the ingress spec is 443, then the backend communication protocol is assumed to be TLS, and will connect via TLS automatically.
Please note that by enabling TLS communication between traefik and your pods, you will have to have trusted certificates that have the proper trust chain and IP subject name.
| `traefik.ingress.kubernetes.io/rate-limit: <YML>` | (2) See [rate limiting](/configuration/commons/#rate-limiting) section. |
| `traefik.ingress.kubernetes.io/redirect-entry-point: https` | Enables Redirect to another entryPoint for that frontend (e.g. HTTPS). |
| `traefik.ingress.kubernetes.io/redirect-permanent: "true"` | Return 301 instead of 302. |
| `traefik.ingress.kubernetes.io/redirect-regex: ^http://localhost/(.*)` | Redirect to another URL for that frontend. Must be set with `traefik.ingress.kubernetes.io/redirect-replacement`. |
| `traefik.ingress.kubernetes.io/redirect-replacement: http://mydomain/$1` | Redirect to another URL for that frontend. Must be set with `traefik.ingress.kubernetes.io/redirect-regex`. |
| `traefik.ingress.kubernetes.io/rewrite-target: /users` | Replaces each matched Ingress path with the specified one, and adds the old path to the `X-Replaced-Path` header. |
Service weights enable to split traffic across multiple backing services in a fine-grained manner.
Example:
```yaml
service_backend1: 12.50%
service_backend2: 12.50%
service_backend3: 75 # Same as 75%, the percentage sign is optional
```
A single service backend definition may be omitted; in this case, Traefik auto-completes that service backend to 100% automatically.
Conveniently, users need not bother to compute the percentage remainder for a main service backend.
For instance, in the example above `service_backend3` does not need to be specified to be assigned 75%.
!!! note
For each service weight given, the Ingress specification must include a backend item with the corresponding `serviceName` and (if given) matching path.
Currently, 3 decimal places for the weight are supported.
An attempt to exceed the precision should be avoided as it may lead to percentage computation flaws and, in consequence, Ingress parsing errors.
For each path definition, this annotation will fail if:
- the sum of backend weights exceeds 100% or
- the sum of backend weights is less than 100% without one or more omitted backends
Please note that `traefik.ingress.kubernetes.io/redirect-regex` and `traefik.ingress.kubernetes.io/redirect-replacement` do not have to be set if `traefik.ingress.kubernetes.io/redirect-entry-point` is defined for the redirection (they will not be used in this case).
| `traefik.ingress.kubernetes.io/max-conn-amount: 10` | Set a maximum number of connections to the backend.<br>Must be used in conjunction with the below label to take effect. |
| `traefik.ingress.kubernetes.io/max-conn-extractor-func: client.ip` | Set the function to be used against the request to determine what to limit maximum connections to the backend by.<br>Must be used in conjunction with the above label to take effect. |
| `traefik.ingress.kubernetes.io/session-cookie-name: <NAME>` | Manually set the cookie name for sticky sessions. |
!!! note
`traefik.ingress.kubernetes.io/` and `ingress.kubernetes.io/` are supported prefixes.
| `ingress.kubernetes.io/custom-request-headers: EXPR` | Provides the container with custom request headers that will be appended to each request forwarded to the container. Format: <code>HEADER:value||HEADER2:value2</code> |
| `ingress.kubernetes.io/custom-response-headers: EXPR` | Appends the headers to each response returned by the container, before forwarding the response to the client. Format: <code>HEADER:value||HEADER2:value2</code> |
| `ingress.kubernetes.io/browser-xss-filter: "true"` | Adds the X-XSS-Protection header with the value `1; mode=block`. |
| `ingress.kubernetes.io/content-security-policy: VALUE` | Adds CSP Header with the custom value. |
| `ingress.kubernetes.io/content-type-nosniff: "true"` | Adds the `X-Content-Type-Options` header with the value `nosniff`. |
| `ingress.kubernetes.io/custom-browser-xss-value: VALUE` | Set custom value for X-XSS-Protection header. This overrides the BrowserXssFilter option. |
| `ingress.kubernetes.io/custom-frame-options-value: VALUE` | Overrides the `X-Frame-Options` header with the custom value. |
| `ingress.kubernetes.io/force-hsts: "false"` | Adds the STS header to non-SSL requests. |
| `ingress.kubernetes.io/frame-deny: "false"` | Adds the `X-Frame-Options` header with the value of `DENY`. |
| `ingress.kubernetes.io/is-development: "false"` | This will cause the `AllowedHosts`, `SSLRedirect`, and `STSSeconds`/`STSIncludeSubdomains` options to be ignored during development.<br>When deploying to production, be sure to set this to false. |
| `ingress.kubernetes.io/proxy-headers: EXPR` | Provides a list of headers that the proxied hostname may be stored. Format: `HEADER1,HEADER2` |
| `ingress.kubernetes.io/ssl-redirect: "true"` | Forces the frontend to redirect to SSL if a non-SSL request is sent. |
| `ingress.kubernetes.io/ssl-temporary-redirect: "true"` | Forces the frontend to redirect to SSL if a non-SSL request is sent, but by sending a 302 instead of a 301. |
| `ingress.kubernetes.io/ssl-host: HOST` | This setting configures the hostname that redirects will be based on. Default is "", which is the same host as the request. |
| `ingress.kubernetes.io/ssl-force-host: "true"` | If `SSLForceHost` is `true` and `SSLHost` is set, requests will be forced to use `SSLHost` even the ones that are already using SSL. Default is false. |
| `ingress.kubernetes.io/ssl-proxy-headers: EXPR` | Header combinations that would signify a proper SSL Request (Such as `X-Forwarded-For:https`). Format: <code>HEADER:value||HEADER2:value2</code> |
| `ingress.kubernetes.io/auth-type: basic` | x | x | x | Contains the authentication type: `basic`, `digest`, `forward`. |
| `ingress.kubernetes.io/auth-secret: mysecret` | x | x | | Name of Secret containing the username and password with access to the paths defined in the Ingress object. |
| `ingress.kubernetes.io/auth-header-field: X-WebAuth-User` | x | x | | Pass Authenticated user to application via headers. |
| `ingress.kubernetes.io/auth-url: https://example.com` | | | x | [The URL of the authentication server](configuration/entrypoints/#forward-authentication). |
Ingresses can be created that look like the following:
```yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: cheese
spec:
backend:
serviceName: stilton
servicePort: 80
```
This ingress follows the [Global Default Backend](https://kubernetes.io/docs/concepts/services-networking/ingress/#the-ingress-resource) property of ingresses.
This will allow users to create a "default backend" that will match all unmatched requests.
!!! note
Due to Træfik's use of priorities, you may have to set this ingress priority lower than other ingresses in your environment, to avoid this global ingress from satisfying requests that _could_ match other ingresses.
To do this, use the `traefik.ingress.kubernetes.io/priority` annotation (as seen in [General Annotations](/configuration/backends/kubernetes/#general-annotations)) on your ingresses accordingly.
