Associate an IAM role with a gateway proxy service account, and configure Gloo Gateway to use that service account to access AWS Lambda.

About

Amazon Web Services (AWS) offers the ability to associate an IAM role with a Kubernetes service account, also known as creating an IRSA. Gloo Gateway supports discovering and invoking AWS Lambda functions by using an IRSA. For more information, see the AWS documentation.

In this guide, you follow these steps:

AWS resources:

  • Associate your EKS cluster with an IAM OIDC provider
  • Create an IAM policy that allows interactions with Lambda functions
  • Create an IAM role that associates the IAM policy with the gateway proxy service account (an IRSA)
  • Deploy the Amazon EKS Pod Identity Webhook to your cluster
  • Create a Lambda function for testing

Gloo Gateway resources:

  • Install Gloo Gateway
  • Annotate the gateway proxy service account with the IRSA
  • Set up routing to your function by creating Upstream and HTTPRoute resources

Configure AWS IAM resources

Save your AWS details, and create an IRSA for the gateway proxy pod to use.

  1. Save the region where your Lambda functions exist, the region where your EKS cluster exists, your cluster name, and the ID of the AWS account.

      export AWS_LAMBDA_REGION=<lambda_function_region>
    export AWS_CLUSTER_REGION=<cluster_region>
    export CLUSTER_NAME=<cluster_name>
    export AWS_ACCOUNT_ID=<account_id>
      
  2. Check whether your EKS cluster has an OIDC provider.

      export OIDC_PROVIDER=$(aws eks describe-cluster --name ${CLUSTER_NAME} --region ${AWS_CLUSTER_REGION} --query "cluster.identity.oidc.issuer" --output text | sed -e "s/^https:\/\///")
    echo $OIDC_PROVIDER
      
    • If an OIDC provider in the format oidc.eks.<region>.amazonaws.com/id/<cluster_id> is returned, continue to the next step.
    • If an OIDC provider is not returned, follow the AWS documentation to Create an IAM OIDC provider for your cluster, and then run this command again to save the OIDC provider in an environment variable.
  3. Create an IAM policy to allow access to the following four Lambda actions. Note that the permissions to discover and invoke functions are listed in the same policy. In a more advanced setup, you might separate discovery and invocation permissions into two IAM policies.

      cat >policy.json <<EOF
    {
       "Version": "2012-10-17",
       "Statement": [
           {
               "Effect": "Allow",
               "Action": [
                   "lambda:ListFunctions",
                   "lambda:InvokeFunction",
                   "lambda:GetFunction",
                   "lambda:InvokeAsync"
               ],
               "Resource": "*"
           }
       ]
    }
    EOF
    
    aws iam create-policy --policy-name lambda-policy --policy-document file://policy.json 
      
  4. Use an IAM role to associate the policy with the Kubernetes service account for the HTTP gateway proxy, which assumes this role to invoke Lambda functions. For more information about these steps, see the AWS documentation.

    1. Create the following IAM role. Note that the service account name http in the gloo-system namespace is specified, because in later steps you create an HTTP gateway named http.
        cat >role.json <<EOF
      {
        "Version": "2012-10-17",
        "Statement": [
          {
            "Effect": "Allow",
            "Principal": {
              "Service": "ec2.amazonaws.com"
            },
            "Action": "sts:AssumeRole"
          },
          {
            "Effect": "Allow",
            "Principal": {
              "Federated": "arn:aws:iam::${AWS_ACCOUNT_ID}:oidc-provider/${OIDC_PROVIDER}"
            },
            "Action": "sts:AssumeRoleWithWebIdentity",
            "Condition": {
              "StringEquals": {
                "${OIDC_PROVIDER}:sub": "system:serviceaccount:gloo-system:http"
              }
            }
          }
        ]
      }
      EOF
      
      aws iam create-role --role-name lambda-role --assume-role-policy-document file://role.json
        
    2. Attach the IAM role to the IAM policy. This IAM role for the service account is known as an IRSA.
        aws iam attach-role-policy --role-name lambda-role --policy-arn=arn:aws:iam::${AWS_ACCOUNT_ID}:policy/lambda-policy
        
    3. Verify that the policy is attached to the role.
        aws iam list-attached-role-policies --role-name lambda-role
        
      Example output:
        {
          "AttachedPolicies": [
              {
                  "PolicyName": "lambda-policy",
                  "PolicyArn": "arn:aws:iam::111122223333:policy/lambda-policy"
              }
          ]
      }
        

Deploy the Amazon EKS Pod Identity Webhook

Before you install Gloo Gateway, deploy the Amazon EKS Pod Identity Webhook, which allows pods’ service accounts to use AWS IAM roles. When you create the Gloo Gateway proxy in the next section, this webhook mutates the proxy’s service account so that it can assume your IAM role to invoke Lambda functions.

  1. In your EKS cluster, install cert-manager, which is a prerequisite for the webhook.

      wget https://github.com/cert-manager/cert-manager/releases/download/v1.12.4/cert-manager.yaml
    kubectl apply -f cert-manager.yaml
      
  2. Verify that all cert-manager pods are running.

      kubectl get pods -n cert-manager
      
  3. Deploy the Amazon EKS Pod Identity Webhook.

      kubectl apply -f https://raw.githubusercontent.com/solo-io/workshops/refs/heads/master/gloo-gateway/1-19/enterprise/lambda/data/steps/deploy-amazon-pod-identity-webhook/auth.yaml
    kubectl apply -f https://raw.githubusercontent.com/solo-io/workshops/refs/heads/master/gloo-gateway/1-19/enterprise/lambda/data/steps/deploy-amazon-pod-identity-webhook/deployment-base.yaml
    kubectl apply -f https://raw.githubusercontent.com/solo-io/workshops/refs/heads/master/gloo-gateway/1-19/enterprise/lambda/data/steps/deploy-amazon-pod-identity-webhook/mutatingwebhook.yaml
    kubectl apply -f https://raw.githubusercontent.com/solo-io/workshops/refs/heads/master/gloo-gateway/1-19/enterprise/lambda/data/steps/deploy-amazon-pod-identity-webhook/service.yaml
      
  4. Verify that the webhook deployment completes.

      kubectl rollout status deploy/pod-identity-webhook
      

Install Gloo Gateway

Be sure that you deployed the Amazon EKS Pod Identity Webhook to your cluster first before you continue to install Gloo Gateway.

  1. Set your Gloo Gateway license key as an environment variable. If you do not have one, contact an account representative.

    If you want to use the capabilities of agentgateway enterprise, you need an additional agentgateway enterprise license.

      export GLOO_GATEWAY_LICENSE_KEY=<gloo-gateway-license-key> 
    export AGENTGATEWAY_LICENSE_KEY=<agentgateway-license-key> 
      

  2. Deploy the Kubernetes Gateway API CRDs.

      kubectl apply -f https://github.com/kubernetes-sigs/gateway-api/releases/download/v1.4.0/standard-install.yaml
      
  3. Deploy the Gloo Gateway CRDs by using Helm. The following command uses the latest stable release, 2.0.2. For active development, update the version to 2.1.0-main.

      helm upgrade -i gloo-gateway-crds oci://us-docker.pkg.dev/solo-public/gloo-gateway/charts/gloo-gateway-crds \
      --create-namespace \
      --namespace gloo-system \
      --version 2.0.2 
      
  4. Install Gloo Gateway by using Helm. Choose between the Envoy-based kgateway proxy or the AI-first agentgateway proxy. You can also enable both gateway proxy types. Note that you need a separate license for each gateway proxy type that you want to enable. For more information, see Gateway proxies.

  5. Make sure that the gloo-gateway control plane is running.

      kubectl get pods -n gloo-system
      

    Example output:

      NAME                            READY   STATUS    RESTARTS   AGE
    gloo-gateway-5495d98459-46dpk   1/1     Running   0          19s
      

Annotate the gateway proxy service account

  1. Create a GatewayParameters resource to specify the eks.amazonaws.com/role-arn IRSA annotation for the gateway proxy service account.

      kubectl apply -f- <<EOF
    apiVersion: gateway.kgateway.dev/v1alpha1
    kind: GatewayParameters
    metadata:
      name: http-lambda
      namespace: gloo-system
    spec:
      kube:
        serviceAccount:
          extraAnnotations:
            eks.amazonaws.com/role-arn: arn:aws:iam::${AWS_ACCOUNT_ID}:role/lambda-role
    EOF
      
  2. Create the following http Gateway resource, which includes a reference to the http-lambda GatewayParameters.

      kubectl apply -f- <<EOF
    kind: Gateway
    apiVersion: gateway.networking.k8s.io/v1
    metadata:
      name: http
      namespace: gloo-system
      annotations:
    spec:
      gatewayClassName: gloo-gateway-v2
      infrastructure:
        parametersRef:
          name: http-lambda
          group: gateway.kgateway.dev
          kind: GatewayParameters        
      listeners:
      - protocol: HTTP
        port: 8080
        name: http
        allowedRoutes:
          namespaces:
            from: All
    EOF
      
  3. Check the status of the gateway to make sure that your configuration is accepted. Note that in the output, a NoConflicts status of False indicates that the gateway is accepted and does not conflict with other gateway configuration.

      kubectl get gateway http -n gloo-system -o yaml
      
  4. Verify that the http service account has the eks.amazonaws.com/role-arn: arn:aws:iam::${AWS_ACCOUNT_ID}:role/lambda-role annotation.

      kubectl describe serviceaccount http -n gloo-system
      

Create a Lambda function

Create an AWS Lambda function to test Gloo Gateway routing.

  1. Log in to the AWS console and navigate to the Lambda page.

  2. Click the Create Function button.

  3. Name the function echo and click Create function.

  4. Replace the default contents of index.mjs with the following Node.js function, which returns a response body that contains exactly what was sent to the function in the request body.

      export const handler = async(event) => {
        const response = {
            statusCode: 200,
            body: `Response from AWS Lambda. Here's the request you just sent me: ${JSON.stringify(event)}`
        };
        return response;
    };
      
  5. Click Deploy.

Set up routing to your function

Create Backend and HTTPRoute resources to route requests to the Lambda function.

  1. Create a Backend resource that references the AWS region, ID of the account that contains the IAM role, and echo function that you created.

      kubectl apply -f - <<EOF
    apiVersion: gateway.kgateway.dev/v1alpha1
    kind: Backend
    metadata:
      name: lambda
      namespace: gloo-system
    spec:
      type: AWS
      aws:
        region: ${AWS_LAMBDA_REGION}
        accountId: "${AWS_ACCOUNT_ID}"
        lambda:
          functionName: echo
    EOF
      
  2. Create an HTTPRoute resource that references the lambda Backend.

      kubectl apply -f - <<EOF
    apiVersion: gateway.networking.k8s.io/v1
    kind: HTTPRoute
    metadata:
      name: lambda
      namespace: gloo-system
    spec:
      parentRefs:
        - name: http
          namespace: gloo-system
      rules:
      - matches:
        - path:
            type: PathPrefix
            value: /echo
        backendRefs:
        - name: lambda
          namespace: gloo-system
          group: gateway.kgateway.dev
          kind: Backend
    EOF
      
  3. Get the external address of the gateway and save it in an environment variable.

  4. Confirm that Gloo Gateway correctly routes requests to Lambda by sending a curl request to the echo function. Note that the first request might take a few seconds to process, because the AWS Security Token Service (STS) credential request must be performed first. However, after the credentials are cached, subsequent requests are processed more quickly.

    Example response:

      {"statusCode":200,"body":"Response from AWS Lambda. Here's the request you just sent me: {\"key1\":\"value1\",\"key2\":\"value2\"}"}% 
      

At this point, Gloo Gateway is routing directly to the echo Lambda function using an IRSA!

Cleanup

You can remove the resources that you created in this guide.

Resources for the echo function

  1. Delete the lambda HTTPRoute and lambda Backend.

      kubectl delete HTTPRoute lambda -n gloo-system
    kubectl delete Backend lambda -n gloo-system
      
  2. Use the AWS Lambda console to delete the echo test function.

IRSA authorization (optional)

If you no longer need to access Lambda functions from Gloo Gateway:

  1. Delete the GatewayParameters resources.

      kubectl delete GatewayParameters http-lambda -n gloo-system
      
  2. Remove the reference to the http-lambda GatewayParameters from the http Gateway.

      kubectl apply -f- <<EOF
    kind: Gateway
    apiVersion: gateway.networking.k8s.io/v1
    metadata:
      name: http
      namespace: gloo-system
    spec:
      gatewayClassName: gloo-gateway-v2
      listeners:
      - protocol: HTTP
        port: 8080
        name: http
        allowedRoutes:
          namespaces:
            from: All
    EOF
      
  3. Delete the pod identity webhook.

      kubectl delete deploy pod-identity-webhook
      
  4. Remove cert-manager.

      kubectl delete -f cert-manager.yaml -n cert-manager
    kubectl delete ns cert-manager
      
  5. Delete the AWS IAM resources that you created.

      aws iam detach-role-policy --role-name lambda-role --policy-arn=arn:aws:iam::${AWS_ACCOUNT_ID}:policy/lambda-policy
    aws iam delete-role --role-name lambda-role
    aws iam delete-policy --policy-arn=arn:aws:iam::${AWS_ACCOUNT_ID}:policy/lambda-policy