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Chapter 9. Tutorial: AWS Load Balancer Operator on ROSA


Important

This content is authored by Red Hat experts, but has not yet been tested on every supported configuration.

Tip

Load Balancers created by the AWS Load Balancer Operator cannot be used for OpenShift Routes, and should only be used for individual services or ingress resources that do not need the full layer 7 capabilities of an OpenShift Route.

The AWS Load Balancer Controller manages AWS Elastic Load Balancers for a Red Hat OpenShift Service on AWS (ROSA) cluster. The controller provisions AWS Application Load Balancers (ALB) when you create Kubernetes Ingress resources and AWS Network Load Balancers (NLB) when implementing Kubernetes Service resources with a type of LoadBalancer.

Compared with the default AWS in-tree load balancer provider, this controller is developed with advanced annotations for both ALBs and NLBs. Some advanced use cases are:

  • Using native Kubernetes Ingress objects with ALBs
  • Integrate ALBs with the AWS Web Application Firewall (WAF) service
  • Specify custom NLB source IP ranges
  • Specify custom NLB internal IP addresses

The AWS Load Balancer Operator is used to used to install, manage and configure an instance of aws-load-balancer-controller in a ROSA cluster.

9.1. Prerequisites

Note

AWS ALBs require a multi-AZ cluster, as well as three public subnets split across three AZs in the same VPC as the cluster. This makes ALBs unsuitable for many PrivateLink clusters. AWS NLBs do not have this restriction.

9.1.1. Environment

  • Prepare the environment variables:

    $ export AWS_PAGER=""
    $ export ROSA_CLUSTER_NAME=$(oc get infrastructure cluster -o=jsonpath="{.status.infrastructureName}"  | sed 's/-[a-z0-9]\{5\}$//')
    $ export REGION=$(oc get infrastructure cluster -o=jsonpath="{.status.platformStatus.aws.region}")
    $ export OIDC_ENDPOINT=$(oc get authentication.config.openshift.io cluster -o jsonpath='{.spec.serviceAccountIssuer}' | sed  's|^https://||')
    $ export AWS_ACCOUNT_ID=$(aws sts get-caller-identity --query Account --output text)
    $ export SCRATCH="/tmp/${ROSA_CLUSTER_NAME}/alb-operator"
    $ mkdir -p ${SCRATCH}
    $ echo "Cluster: ${ROSA_CLUSTER_NAME}, Region: ${REGION}, OIDC Endpoint: ${OIDC_ENDPOINT}, AWS Account ID: ${AWS_ACCOUNT_ID}"

9.1.2. AWS VPC and subnets

Note

This section only applies to clusters that were deployed into existing VPCs. If you did not deploy your cluster into an existing VPC, skip this section and proceed to the installation section below.

  1. Set the below variables to the proper values for your ROSA deployment:

    $ export VPC_ID=<vpc-id>
    $ export PUBLIC_SUBNET_IDS=<public-subnets>
    $ export PRIVATE_SUBNET_IDS=<private-subnets>
    $ export CLUSTER_NAME=$(oc get infrastructure cluster -o=jsonpath="{.status.infrastructureName}")
  2. Add a tag to your cluster’s VPC with the cluster name:

    $ aws ec2 create-tags --resources ${VPC_ID} --tags Key=kubernetes.io/cluster/${CLUSTER_NAME},Value=owned --region ${REGION}
  3. Add a tag to your public subnets:

    $ aws ec2 create-tags \
         --resources ${PUBLIC_SUBNET_IDS} \
         --tags Key=kubernetes.io/role/elb,Value='' \
         --region ${REGION}
  4. Add a tag to your private subnets:

    $ aws ec2 create-tags \
         --resources "${PRIVATE_SUBNET_IDS}" \
         --tags Key=kubernetes.io/role/internal-elb,Value='' \
         --region ${REGION}

9.2. Installation

  1. Create an AWS IAM policy for the AWS Load Balancer Controller:

    Note

    The policy is sourced from the upstream AWS Load Balancer Controller policy plus permission to create tags on subnets. This is required by the operator to function.

    $ oc new-project aws-load-balancer-operator
    $ POLICY_ARN=$(aws iam list-policies --query \
         "Policies[?PolicyName=='aws-load-balancer-operator-policy'].{ARN:Arn}" \
         --output text)
    $ if [[ -z "${POLICY_ARN}" ]]; then
        wget -O "${SCRATCH}/load-balancer-operator-policy.json" \
           https://raw.githubusercontent.com/rh-mobb/documentation/main/content/rosa/aws-load-balancer-operator/load-balancer-operator-policy.json
         POLICY_ARN=$(aws --region "$REGION" --query Policy.Arn \
         --output text iam create-policy \
         --policy-name aws-load-balancer-operator-policy \
         --policy-document "file://${SCRATCH}/load-balancer-operator-policy.json")
    fi
    $ echo $POLICY_ARN
  2. Create an AWS IAM trust policy for AWS Load Balancer Operator:

    $ cat <<EOF > "${SCRATCH}/trust-policy.json"
    {
     "Version": "2012-10-17",
     "Statement": [
     {
     "Effect": "Allow",
     "Condition": {
       "StringEquals" : {
         "${OIDC_ENDPOINT}:sub": ["system:serviceaccount:aws-load-balancer-operator:aws-load-balancer-operator-controller-manager", "system:serviceaccount:aws-load-balancer-operator:aws-load-balancer-controller-cluster"]
       }
     },
     "Principal": {
       "Federated": "arn:aws:iam::$AWS_ACCOUNT_ID:oidc-provider/${OIDC_ENDPOINT}"
     },
     "Action": "sts:AssumeRoleWithWebIdentity"
     }
     ]
    }
    EOF
  3. Create an AWS IAM role for the AWS Load Balancer Operator:

    $ ROLE_ARN=$(aws iam create-role --role-name "${ROSA_CLUSTER_NAME}-alb-operator" \
       --assume-role-policy-document "file://${SCRATCH}/trust-policy.json" \
       --query Role.Arn --output text)
    $ echo $ROLE_ARN
    
    $ aws iam attach-role-policy --role-name "${ROSA_CLUSTER_NAME}-alb-operator" \
         --policy-arn $POLICY_ARN
  4. Create a secret for the AWS Load Balancer Operator to assume our newly created AWS IAM role:

    $ cat << EOF | oc apply -f -
    apiVersion: v1
    kind: Secret
    metadata:
      name: aws-load-balancer-operator
      namespace: aws-load-balancer-operator
    stringData:
      credentials: |
        [default]
        role_arn = $ROLE_ARN
        web_identity_token_file = /var/run/secrets/openshift/serviceaccount/token
    EOF
  5. Install the AWS Load Balancer Operator:

    $ cat << EOF | oc apply -f -
    apiVersion: operators.coreos.com/v1
    kind: OperatorGroup
    metadata:
      name: aws-load-balancer-operator
      namespace: aws-load-balancer-operator
    spec:
      upgradeStrategy: Default
    ---
    apiVersion: operators.coreos.com/v1alpha1
    kind: Subscription
    metadata:
      name: aws-load-balancer-operator
      namespace: aws-load-balancer-operator
    spec:
      channel: stable-v1.0
      installPlanApproval: Automatic
      name: aws-load-balancer-operator
      source: redhat-operators
      sourceNamespace: openshift-marketplace
      startingCSV: aws-load-balancer-operator.v1.0.0
    EOF
  6. Deploy an instance of the AWS Load Balancer Controller using the operator:

    Note

    If you get an error here wait a minute and try again, it means the Operator has not completed installing yet.

    $ cat << EOF | oc apply -f -
    apiVersion: networking.olm.openshift.io/v1
    kind: AWSLoadBalancerController
    metadata:
      name: cluster
    spec:
      credentials:
        name: aws-load-balancer-operator
    EOF
  7. Check the that the operator and controller pods are both running:

    $ oc -n aws-load-balancer-operator get pods

    You should see the following, if not wait a moment and retry:

    NAME                                                             READY   STATUS    RESTARTS   AGE
    aws-load-balancer-controller-cluster-6ddf658785-pdp5d            1/1     Running   0          99s
    aws-load-balancer-operator-controller-manager-577d9ffcb9-w6zqn   2/2     Running   0          2m4s

9.3. Validating the deployment

  1. Create a new project:

    $ oc new-project hello-world
  2. Deploy a hello world application:

    $ oc new-app -n hello-world --image=docker.io/openshift/hello-openshift
  3. Configure a NodePort service for the AWS ALB to connect to:

    $ cat << EOF | oc apply -f -
    apiVersion: v1
    kind: Service
    metadata:
      name: hello-openshift-nodeport
      namespace: hello-world
    spec:
      ports:
        - port: 80
          targetPort: 8080
          protocol: TCP
      type: NodePort
      selector:
        deployment: hello-openshift
    EOF
  4. Deploy an AWS ALB using the AWS Load Balancer Operator:

    $ cat << EOF | oc apply -f -
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: hello-openshift-alb
      namespace: hello-world
      annotations:
        alb.ingress.kubernetes.io/scheme: internet-facing
    spec:
      ingressClassName: alb
      rules:
        - http:
            paths:
              - path: /
                pathType: Exact
                backend:
                  service:
                    name: hello-openshift-nodeport
                    port:
                      number: 80
    EOF
  5. Curl the AWS ALB Ingress endpoint to verify the hello world application is accessible:

    Note

    AWS ALB provisioning takes a few minutes. If you receive an error that says curl: (6) Could not resolve host, please wait and try again.

    $ INGRESS=$(oc -n hello-world get ingress hello-openshift-alb \
        -o jsonpath='{.status.loadBalancer.ingress[0].hostname}')
    $ curl "http://${INGRESS}"

    Example output

    Hello OpenShift!

  6. Deploy an AWS NLB for your hello world application:

    $ cat << EOF | oc apply -f -
    apiVersion: v1
    kind: Service
    metadata:
      name: hello-openshift-nlb
      namespace: hello-world
      annotations:
        service.beta.kubernetes.io/aws-load-balancer-type: external
        service.beta.kubernetes.io/aws-load-balancer-nlb-target-type: instance
        service.beta.kubernetes.io/aws-load-balancer-scheme: internet-facing
    spec:
      ports:
        - port: 80
          targetPort: 8080
          protocol: TCP
      type: LoadBalancer
      selector:
        deployment: hello-openshift
    EOF
  7. Test the AWS NLB endpoint:

    Note

    NLB provisioning takes a few minutes. If you receive an error that says curl: (6) Could not resolve host, please wait and try again.

    $ NLB=$(oc -n hello-world get service hello-openshift-nlb \
      -o jsonpath='{.status.loadBalancer.ingress[0].hostname}')
    $ curl "http://${NLB}"

    Example output

    Hello OpenShift!

9.4. Cleaning up

  1. Delete the hello world application namespace (and all the resources in the namespace):

    $ oc delete project hello-world
  2. Delete the AWS Load Balancer Operator and the AWS IAM roles:

    $ oc delete subscription aws-load-balancer-operator -n aws-load-balancer-operator
    $ aws iam detach-role-policy \
      --role-name "${ROSA_CLUSTER_NAME}-alb-operator" \
      --policy-arn $POLICY_ARN
    $ aws iam delete-role \
      --role-name "${ROSA_CLUSTER_NAME}-alb-operator"
  3. Delete the AWS IAM policy:

    $ aws iam delete-policy --policy-arn $POLICY_ARN
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