Verifying DynamoDB access

Now, with the carts Service Account associated with the authorized IAM role, the carts Pod has permission to access the DynamoDB table. Access the web store again and navigate to the shopping cart.

~$LB_HOSTNAME=$(kubectl -n ui get service ui-nlb -o jsonpath='{.status.loadBalancer.ingress[*].hostname}{"\n"}')

~$echo "http://$LB_HOSTNAME"

http://k8s-ui-uinlb-647e781087-6717c5049aa96bd9.elb.us-west-2.amazonaws.com

The carts Pod is able to reach the DynamoDB service and the shopping cart is now accessible!

After the AWS IAM role is associated with the Service Account, any newly created Pods using that Service Account will be intercepted by the EKS Pod Identity webhook. This webhook runs on the Amazon EKS cluster's control plane and is fully managed by AWS. Take a closer look at the new carts Pod to see the new environment variables:

~$kubectl -n carts exec deployment/carts -- env | grep AWS

AWS_STS_REGIONAL_ENDPOINTS=regional

AWS_DEFAULT_REGION=us-west-2

AWS_REGION=us-west-2

AWS_CONTAINER_CREDENTIALS_FULL_URI=http://169.254.170.23/v1/credentials

AWS_CONTAINER_AUTHORIZATION_TOKEN_FILE=/var/run/secrets/pods.eks.amazonaws.com/serviceaccount/eks-pod-identity-token

Notable points about these environment variables:

• AWS_DEFAULT_REGION - The region is set automatically to the same as our EKS cluster
• AWS_STS_REGIONAL_ENDPOINTS - Regional STS endpoints are configured to avoid putting too much pressure on the global endpoint in us-east-1
• AWS_CONTAINER_CREDENTIALS_FULL_URI - This variable tells AWS SDKs how to obtain credentials using the HTTP credential provider. This means that EKS Pod Identity does not need to inject credentials via something like an AWS_ACCESS_KEY_ID/AWS_SECRET_ACCESS_KEY pair, and instead the SDKs can have temporary credentials vended to them via the EKS Pod Identity mechanism. You can read more about how this functions in the AWS documentation.

You have successfully configured Pod Identity in your application.