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Chapter 9. Tutorial: AWS Load Balancer Operator on ROSA
This content is authored by Red Hat experts, but has not yet been tested on every supported configuration.
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
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.
- A multi-AZ ROSA classic cluster
- BYO VPC cluster
- AWS CLI
- OC CLI
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
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.
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}")
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}
Add a tag to your public subnets:
$ aws ec2 create-tags \ --resources ${PUBLIC_SUBNET_IDS} \ --tags Key=kubernetes.io/role/elb,Value='' \ --region ${REGION}
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
Create an AWS IAM policy for the AWS Load Balancer Controller:
NoteThe 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
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
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
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
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
Deploy an instance of the AWS Load Balancer Controller using the operator:
NoteIf 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
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
Create a new project:
$ oc new-project hello-world
Deploy a hello world application:
$ oc new-app -n hello-world --image=docker.io/openshift/hello-openshift
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
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
Curl the AWS ALB Ingress endpoint to verify the hello world application is accessible:
NoteAWS 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!
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
Test the AWS NLB endpoint:
NoteNLB 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
Delete the hello world application namespace (and all the resources in the namespace):
$ oc delete project hello-world
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"
Delete the AWS IAM policy:
$ aws iam delete-policy --policy-arn $POLICY_ARN