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ALB Ingress Controller Configuration

This document covers configuration of the ALB ingress controller

AWS API Access

To perform operations, the controller must have required IAM role capabilities for accessing and provisioning ALB resources. There are many ways to achieve this, such as loading AWS_ACCESS_KEY_ID/AWS_SECRET_ACCESS_KEY as environment variables or using kube2iam.

A sample IAM policy, with the minimum permissions to run the controller, can be found in alb-iam-policy.json.

Setting Ingress Resource Scope

You can limit the ingresses ALB ingress controller controls by combining following two approaches:

Limiting ingress class

Setting the --ingress-class argument constrains the controller's scope to ingresses with matching kubernetes.io/ingress.class annotation. This is especially helpful when running multiple ingress controllers in the same cluster. See Using Multiple Ingress Controllers for more details.

An example of the container spec portion of the controller, only listening for resources with the class "alb", would be as follows.

spec:
  containers:
  - args:
    - --ingress-class=alb

Now, only ingress resources with the appropriate annotation are picked up, as seen below.

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: echoserver
  namespace: echoserver
  annotations:
    kubernetes.io/ingress.class: "alb"
spec:
    ...

Limiting Namespaces

Setting the --watch-namespace argument constrains the controller's scope to a single namespace. Ingress events outside of the namespace specified are not be seen by the controller.

An example of the container spec, for a controller watching only the default namespace, is as follows.

spec:
  containers:
  - args:
    - --watch-namespace=default

Currently, you can set only 1 namespace to watch in this flag. See this Kubernetes issue for more details.

Limiting External Namespaces

Setting the --restrict-scheme boolean flag to true will enable the ALB controller to check the configmap named alb-ingress-controller-internet-facing-ingresses for a list of approved ingresses before provisioning ALBs with an internet-facing scheme. Here is an example of that ConfigMap:

apiVersion: v1
data:
 mynamespace: my-ingress-name, my-ingress-name-2
 myothernamespace: my-other-ingress-name
kind: ConfigMap
metadata:
  name: alb-ingress-controller-internet-facing-ingresses

This ConfigMap is kept in default if unspecified, and can be overridden via the --restrict-scheme-namespace flag.

Resource Tags

Setting the --default-tags argument adds arbitrary tags to ALBs and target groups managed by the ingress controller.

spec:
  containers:
  - args:
    - /server
    - --default-tags=mykey=myvalue,otherkey=othervalue

Subnet Auto Discovery

You can tag AWS subnets to allow ingress controller auto discover subnets used for ALBs.

  • kubernetes.io/cluster/${cluster-name} must be set to owned or shared

  • kubernetes.io/role/internal-elb must be set to 1 or `` for internal LoadBalancers

  • kubernetes.io/role/elb must be set to 1 or `` for internet-facing LoadBalancers

An example of a subnet with the correct tags for the cluster joshcalico is as follows: subnet-tags