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Access AWS Lambda with a service account

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 resources:

Install Gloo Gateway, including settings to annotate the gateway proxy service account with the IRSA
Set up routing to your function by creating Upstream and HTTPRoute resources

Before you begin

Before you begin, review the following considerations:

warning

This guide requires you to enable IAM settings in your EKS cluster, such as the AWS Pod Identity Webhook, before you deploy Gloo Gateway components that are created during installation, such as the Gateway CRD and the gateway proxy service account. You might use this guide with a fresh EKS test cluster to try out Lambda function invocation with Gloo Gateway service accounts.

info

The following steps assume that the AWS account you use to authenticate with Gloo Gateway also contains the Lambda functions that you want to route to. To instead allow Gloo Gateway to route requests to Lambda functions that exist in different accounts, see Configure cross-account Lambda access.

Configure AWS IAM resources

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

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 ACCOUNT_ID=<account_id>

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.

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 gloo-lambda-policy --policy-document file://policy.json

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.

Create the following IAM role. Note that the service account name gloo-proxy-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": {
        "Federated": "arn:aws:iam::${ACCOUNT_ID}:oidc-provider/${OIDC_PROVIDER}"
      },
      "Action": "sts:AssumeRoleWithWebIdentity",
      "Condition": {
        "StringEquals": {
          "${OIDC_PROVIDER}:sub": [
            "system:serviceaccount:gloo-system:gloo-proxy-http"
          ]
        }
      }
    }
  ]
}
EOF

aws iam create-role --role-name gloo-lambda-role --assume-role-policy-document file://role.json

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 gloo-lambda-role --policy-arn=arn:aws:iam::${ACCOUNT_ID}:policy/gloo-lambda-policy

Verify that the policy is attached to the role.

  aws iam list-attached-role-policies --role-name gloo-lambda-role

Example output:

  {
    "AttachedPolicies": [
        {
            "PolicyName": "gloo-lambda-policy",
            "PolicyArn": "arn:aws:iam::111122223333:policy/gloo-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.

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

Verify that all cert-manager pods are running.
```
  kubectl get pods -n cert-manager
  
```

Deploy the Amazon EKS Pod Identity Webhook.

  kubectl apply -f https://raw.githubusercontent.com/solo-io/workshops/refs/heads/master/gloo-gateway/1-18/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/1-18/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/1-18/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/1-18/enterprise/lambda/data/steps/deploy-amazon-pod-identity-webhook/service.yaml

Verify that the webhook deployment completes.

  kubectl rollout status deploy/pod-identity-webhook

Install Gloo Gateway with service account authentication

Install the open source or enterprise edition of Gloo Gateway, including settings to support gateway proxy service account authentication with your AWS account.

Open source

Install the custom resources of the Kubernetes Gateway API.

  kubectl apply -f https://github.com/kubernetes-sigs/gateway-api/releases/download/v1.3.0/standard-install.yaml

Example output:

  customresourcedefinition.apiextensions.k8s.io/gatewayclasses.gateway.networking.k8s.io created
customresourcedefinition.apiextensions.k8s.io/gateways.gateway.networking.k8s.io created
customresourcedefinition.apiextensions.k8s.io/httproutes.gateway.networking.k8s.io created
customresourcedefinition.apiextensions.k8s.io/referencegrants.gateway.networking.k8s.io created
customresourcedefinition.apiextensions.k8s.io/grpcroutes.gateway.networking.k8s.io created

Add the Helm repository for Gloo Gateway Open Source.

  helm repo add gloo https://storage.googleapis.com/solo-public-helm
helm repo update

Install Gloo Gateway. This command creates the gloo-system namespace and installs the Gloo Gateway control plane into it. The following settings also enable Gloo Gateway to use an AWS IRSA and annotate the gloo-proxy-http service account.

  helm install -n gloo-system gloo gloo/gloo \
--create-namespace \
--version 1.20.3 \
-f -<<EOF
gatewayProxies:
  gatewayProxy:
    disabled: true
gloo:
  disableLeaderElection: true
kubeGateway:
  enabled: true
  # Annotate the gateway proxy service account
  gatewayParameters:
    glooGateway:
      serviceAccount:
        extraAnnotations:
          eks.amazonaws.com/role-arn: arn:aws:iam::${ACCOUNT_ID}:role/gloo-lambda-role
# Enable AWS account authentication with IRSA
settings:
  aws:
    enableServiceAccountCredentials: true
    stsCredentialsRegion: ${AWS_LAMBDA_REGION}
EOF

Example output:

  NAME: gloo-gateway
LAST DEPLOYED: Thu Apr 18 11:50:39 2024
NAMESPACE: gloo-system
STATUS: deployed
REVISION: 2
TEST SUITE: None

Verify that the Gloo Gateway control plane is up and running.

  kubectl get pods -n gloo-system | grep gloo

Example output:

  NAME                                  READY   STATUS    RESTARTS   AGE
gloo-78658959cd-cz6jt                 1/1     Running   0          12s

Enterprise edition

Set your Gloo Gateway license key as an environment variable. If you do not have one, contact an account representative.
```
  export GLOO_GATEWAY_LICENSE_KEY=<license-key>
  
```

Install the custom resources of the Kubernetes Gateway API.

  kubectl apply -f https://github.com/kubernetes-sigs/gateway-api/releases/download/v1.3.0/standard-install.yaml

Example output:

  customresourcedefinition.apiextensions.k8s.io/gatewayclasses.gateway.networking.k8s.io created
customresourcedefinition.apiextensions.k8s.io/gateways.gateway.networking.k8s.io created
customresourcedefinition.apiextensions.k8s.io/httproutes.gateway.networking.k8s.io created
customresourcedefinition.apiextensions.k8s.io/referencegrants.gateway.networking.k8s.io created
customresourcedefinition.apiextensions.k8s.io/grpcroutes.gateway.networking.k8s.io created

Add the Helm repository for Gloo Gateway Enterprise Edition.

  helm repo add glooe https://storage.googleapis.com/gloo-ee-helm
helm repo update

  helm install -n gloo-system gloo glooe/gloo-ee \
--create-namespace \
--version 1.20.3 \
--set-string license_key=$GLOO_GATEWAY_LICENSE_KEY \
-f -<<EOF
gloo:
  gatewayProxies:
    gatewayProxy:
      disabled: true
  kubeGateway:
    enabled: true
    # Annotate the gateway proxy service account
    gatewayParameters:
      glooGateway:
        serviceAccount:
          extraAnnotations:
            eks.amazonaws.com/role-arn: arn:aws:iam::${ACCOUNT_ID}:role/gloo-lambda-role
  gloo:
    disableLeaderElection: true
  # Enable AWS account authentication with IRSA
  settings:
    aws:
      enableServiceAccountCredentials: true
      stsCredentialsRegion: ${AWS_LAMBDA_REGION}
gloo-fed:
  enabled: false
  glooFedApiserver:
    enable: false
grafana:
  defaultInstallationEnabled: false
observability:
  enabled: false
prometheus:
  enabled: false
EOF

Example output:

  NAME: gloo-gateway
LAST DEPLOYED: Thu Apr 18 11:50:39 2024
NAMESPACE: gloo-system
STATUS: deployed
REVISION: 2
TEST SUITE: None

Verify that the Gloo Gateway control plane is up and running.

  kubectl get pods -n gloo-system

Example output:

  NAME                                READY   STATUS      RESTARTS   AGE
extauth-64458459c8-9q9kq            1/1     Running     0          26s
gateway-certgen-qpv5q               0/1     Completed   0          31s
gloo-68846f8459-nbzxp               1/1     Running     0          26s
gloo-resource-rollout-check-xskxt   0/1     Completed   0          25s
gloo-resource-rollout-n9kvf         0/1     Completed   0          26s
rate-limit-5d8f859465-qhgsg         1/1     Running     0          26s
redis-9f4f98445-5fh69               1/1     Running     0          26s

Create a gateway proxy and annotate its service account

Create an HTTP gateway, and verify that its service account is annotated.

Create a Gateway resource and configure an HTTP listener.

  kubectl apply -n gloo-system -f- <<EOF
kind: Gateway
apiVersion: gateway.networking.k8s.io/v1
metadata:
  name: http
spec:
  gatewayClassName: gloo-gateway
  listeners:
  - protocol: HTTP
    port: 8080
    name: http
    allowedRoutes:
      namespaces:
        from: All
EOF

Verify that the gateway is created successfully. You can also review the external address that is assigned to the gateway. Note that depending on your environment it might take a few minutes for the load balancer service to be assigned an external address.

  kubectl get gateway http -n gloo-system

Example output:

  NAME   CLASS          ADDRESS                                                                  PROGRAMMED   AGE
http   gloo-gateway   a3a6c06e2f4154185bf3f8af46abf22e-139567718.us-east-2.elb.amazonaws.com   True         93s

Get the external address of the gateway and save it in an environment variable.

  export INGRESS_GW_ADDRESS=$(kubectl get svc -n gloo-system gloo-proxy-http -o jsonpath="{.status.loadBalancer.ingress[0]['hostname','ip']}")
echo $INGRESS_GW_ADDRESS

  kubectl port-forward deployment/gloo-proxy-http -n gloo-system 8080:8080

Verify that the gloo-proxy-http service account has the eks.amazonaws.com/role-arn: arn:aws:iam::${ACCOUNT_ID}:role/gloo-lambda-role annotation.
```
  kubectl describe serviceaccount gloo-proxy-http -n gloo-system
  
```

Create a Lambda function for testing

Create an AWS Lambda function to test routing.

Log in to the AWS console and navigate to the Lambda page.
Click the Create Function button.
Name the function echo and click Create function.

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;
};

Click Deploy.

Set up routing to your function

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

Create an Upstream resource that references the AWS region, IAM role, and echo function that you created. Note that you can specify multiple functions as a list in the spec.aws.lambdaFunctions array.

  kubectl apply -f - <<EOF
apiVersion: gloo.solo.io/v1
kind: Upstream
metadata:
  name: lambda
  namespace: gloo-system
spec:
  aws: 
    region: ${AWS_LAMBDA_REGION}
    roleArn: arn:aws:iam::${ACCOUNT_ID}:role/gloo-lambda-role
    lambdaFunctions:
    - lambdaFunctionName: echo
      logicalName: echo
EOF

Create an HTTPRoute resource that references the lambda Upstream.
- In the rules.matches section, specify a request matcher for your Lambda function, such as the PathPrefix match to /echo in the following example.
- In the backendRefs.filters.extensionRef.name field, specify your Lambda function name. This extensionRef tells Gloo Gateway which function in the Upstream to reference, because multiple functions can be listed in the spec.aws.lambdaFunctions array of the Upstream. To route to another function that you listed in the same Upstream, you can either add another rule entry in this same HTTPRoute that references the same Upstream with a different extensionRef for the function name, or create a new HTTPRoute to define the routing rule.
notifications
You cannot currently attach a prefixRewrite policy to a Lambda Upstream.
```
  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: gloo.solo.io
      kind: Upstream
      filters:
        - type: ExtensionRef
          extensionRef:
            group: "gloo.solo.io"
            kind: Parameter
            name: echo
EOF
  
```
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.
Cloud Provider LoadBalancer Port-forward for local testing
```
  curl $INGRESS_GW_ADDRESS:8080/echo -d '{"key1":"value1", "key2":"value2"}' -X POST
  
```
```
  curl localhost:8080/echo -d '{"key1":"value1", "key2":"value2"}' -X POST
  
```
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 optionally remove the resources that you set up as part of this guide.

Resources for the `echo` function

Delete the lambda HTTPRoute and lambda Upstream.

  kubectl delete HTTPRoute lambda -n gloo-system
kubectl delete Upstream lambda -n gloo-system

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:

Upgrade your Gloo Gateway Helm installation to remove the added settings and annotation.
1. Get the Helm values for your current installation, and save them in a file.
```
  helm get values gloo -n gloo-system -o yaml > gloo-gateway.yaml
open gloo-gateway.yaml
  
```
2. Delete the following settings, and save the file. For Enterprise edition, these settings are in the gloo section.
  - kubeGateway.gatewayParameters.glooGateway.serviceAccount.extraAnnotations
  - settings.aws.enableServiceAccountCredentials
  - settings.aws.stsCredentialsRegion
3. Upgrade the Helm release. Replace the example Gloo Gateway version with the version that you run.
  - Open source:
```
  helm upgrade -n gloo-system gloo gloo/gloo \
  -f gloo-gateway.yaml \
  --version=1.20.3
  
```
  - Enterprise edition:
```
  helm upgrade -n gloo-system gloo glooe/gloo-ee \
  -f gloo-gateway.yaml \
  --version=1.20.3
  
```

Delete the pod identity webhook.

  kubectl delete deploy pod-identity-webhook

Remove cert-manager.

  kubectl delete -f cert-manager.yaml -n cert-manager
kubectl delete ns cert-manager

Delete the AWS IAM resources that you created.

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

Access AWS Lambda with a service account

About link

Before you begin link

Configure AWS IAM resources link

Deploy the Amazon EKS Pod Identity Webhook link

Install Gloo Gateway with service account authentication link

Open source link

Enterprise edition link

Create a gateway proxy and annotate its service account link

Create a Lambda function for testing link

Set up routing to your function link

Cleanup link

Resources for the echo function link

IRSA authorization (optional) link

About

Before you begin

Configure AWS IAM resources

Deploy the Amazon EKS Pod Identity Webhook

Install Gloo Gateway with service account authentication

Open source

Enterprise edition

Create a gateway proxy and annotate its service account

Create a Lambda function for testing

Set up routing to your function

Cleanup

Resources for the `echo` function

IRSA authorization (optional)