Annotations for Application Gateway Ingress Controller

• 11/4/2019
• 3 minutes to read
• • C
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Introductions

The Kubernetes Ingress resource can be annotated with arbitrary key/value pairs. AGIC relies on annotations to program Application Gateway features, which are not configurable via the Ingress YAML. Ingress annotations are applied to all HTTP setting, backend pools, and listeners derived from an ingress resource.

List of supported annotations

For an Ingress resource to be observed by AGIC, it must be annotated with kubernetes.io/ingress.class: azure/application-gateway. Only then AGIC will work with the Ingress resource in question.

Backend Path Prefix

This annotation allows the backend path specified in an ingress resource to be rewritten with prefix specified in this annotation. This allows users to expose services whose endpoints are different than endpoint names used to expose a service in an ingress resource.

Usage

appgw.ingress.kubernetes.io/backend-path-prefix: <path prefix>

Example

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: go-server-ingress-bkprefix
  namespace: test-ag
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
    appgw.ingress.kubernetes.io/backend-path-prefix: "/test/"
spec:
  rules:
  - http:
      paths:
      - path: /hello/
        backend:
          serviceName: go-server-service
          servicePort: 80

In the example above, we have defined an ingress resource named go-server-ingress-bkprefix with an annotation appgw.ingress.kubernetes.io/backend-path-prefix: "/test/" . The annotation tells application gateway to create an HTTP setting, which will have a path prefix override for the path /hello to /test/.

TLS Redirect

Application Gateway can be configured to automatically redirect HTTP URLs to their HTTPS counterparts. When this annotation is present and TLS is properly configured, Kubernetes Ingress controller will create a routing rule with a redirection configuration and apply the changes to your Application Gateway. The redirect created will be HTTP 301 Moved Permanently.

Usage

appgw.ingress.kubernetes.io/ssl-redirect: "true"

Example

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: go-server-ingress-redirect
  namespace: test-ag
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
    appgw.ingress.kubernetes.io/ssl-redirect: "true"
spec:
  tls:
   - hosts:
     - www.contoso.com
     secretName: testsecret-tls
  rules:
  - host: www.contoso.com
    http:
      paths:
      - backend:
          serviceName: websocket-repeater
          servicePort: 80

Connection Draining

connection-draining: This annotation allows users to specify whether to enable connection draining. connection-draining-timeout: This annotation allows users to specify a timeout after which Application Gateway will terminate the requests to the draining backend endpoint.

Usage

appgw.ingress.kubernetes.io/connection-draining: "true"
appgw.ingress.kubernetes.io/connection-draining-timeout: "60"

Example

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: go-server-ingress-drain
  namespace: test-ag
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
    appgw.ingress.kubernetes.io/connection-draining: "true"
    appgw.ingress.kubernetes.io/connection-draining-timeout: "60"
spec:
  rules:
  - http:
      paths:
      - path: /hello/
        backend:
          serviceName: go-server-service
          servicePort: 80

Cookie Based Affinity

This annotation allows to specify whether to enable cookie based affinity.

Usage

appgw.ingress.kubernetes.io/cookie-based-affinity: "true"

Example

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: go-server-ingress-affinity
  namespace: test-ag
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
    appgw.ingress.kubernetes.io/cookie-based-affinity: "true"
spec:
  rules:
  - http:
      paths:
      - path: /hello/
        backend:
          serviceName: go-server-service
          servicePort: 80

Request Timeout

This annotation allows to specify the request timeout in seconds after which Application Gateway will fail the request if response is not received.

Usage

appgw.ingress.kubernetes.io/request-timeout: "20"

Example

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: go-server-ingress-timeout
  namespace: test-ag
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
    appgw.ingress.kubernetes.io/request-timeout: "20"
spec:
  rules:
  - http:
      paths:
      - path: /hello/
        backend:
          serviceName: go-server-service
          servicePort: 80

Use Private IP

This annotation allows us to specify whether to expose this endpoint on Private IP of Application Gateway.

Usage

appgw.ingress.kubernetes.io/use-private-ip: "true"

Example

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: go-server-ingress-timeout
  namespace: test-ag
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
    appgw.ingress.kubernetes.io/use-private-ip: "true"
spec:
  rules:
  - http:
      paths:
      - path: /hello/
        backend:
          serviceName: go-server-service
          servicePort: 80

Backend Protocol

This annotation allows us to specify the protocol that Application Gateway should use while talking to the Pods. Supported Protocols: http, https

Usage

appgw.ingress.kubernetes.io/backend-protocol: "https"

Example

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: go-server-ingress-timeout
  namespace: test-ag
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
    appgw.ingress.kubernetes.io/backend-protocol: "https"
spec:
  rules:
  - http:
      paths:
      - path: /hello/
        backend:
          serviceName: go-server-service
          servicePort: 443