Introduction: The Evolution of Credential Management in AWS EKS

Kubernetes has become the go-to solution for container orchestration, and Amazon EKS (Elastic Kubernetes Service) is one of the most popular managed Kubernetes services in the cloud. However, managing credentials and access controls within Kubernetes clusters has historically been challenging. Early solutions required attaching IAM (Identity and Access Management) roles directly to nodes, which needed granular control. This process evolved with IAM roles for service accounts, but even that had its limitations.

Enter AWS EKS Pod Identity, a streamlined, AWS-native solution that simplifies credential management for Kubernetes pods. This guide will help you understand and implement EKS Pod Identity to enhance security, automation, and control in your Kubernetes clusters.

The Challenge of IAM Roles for Service Accounts

IAM roles for service accounts (IRSA) addressed some issues in Kubernetes by allowing specific pods to assume roles rather than relying on node-based permissions. While this was an improvement, it still required complex configurations, particularly for managing trust relationships between accounts and ensuring the right roles were mapped to the appropriate pods. Moreover, automation was challenging to implement without sacrificing clarity or control over permissions.

EKS Pod Identity: A Streamlined Solution

AWS EKS Pod Identity offers a more refined approach by directly associating IAM roles with pods using Kubernetes service accounts. This solution eliminates the need for node-specific permissions, offers granular access control, and streamlines the automation of IAM roles. With EKS Pod Identity, administrators can assign precise permissions at the pod level, reducing security risks and simplifying overall credential management.

Implementing EKS Pod Identity: A Hands-On Approach

Now that we understand the problem and the solution let’s dive into the practical steps for implementing EKS Pod Identity in your AWS environment.

1. Creating an EKS Cluster with Pod Identity Agent

The first step is to create an Amazon EKS cluster. This cluster will include the Pod Identity Webhook, which acts as an agent to manage role assumption at the pod level. You can create an EKS cluster using the AWS Management Console, AWS CLI, or infrastructure-as-code tools like eksctl or Terraform.

eksctl create cluster \

  –name my-cluster \

  –region us-west-2 \

  –with-oidc \

  –nodes 3

The –with-oidc flag ensures that an OIDC (OpenID Connect) provider is created, enabling pod identity in the cluster.

2. Defining IAM Roles and Policies

Once the cluster is created, the next step is to define the IAM roles and policies that the pods will assume. You will need to create a role that includes the necessary permissions for your application, such as access to specific AWS services like S3, DynamoDB, or RDS.

aws iam create-role \

  –role-name EKS-Pod-Role \

  –assume-role-policy-document file://trust-policy.json

In the trust-policy.json, define the trusted entities as the OIDC provider associated with the EKS cluster.

3. Configuring EKS Resources

With the IAM role in place, the next step is to configure Kubernetes resources. Create a Kubernetes service account that maps to the IAM role defined earlier. This is done by annotating the service account with the role ARN.

kubectl create serviceaccount my-serviceaccount

kubectl annotate serviceaccount my-serviceaccount \

  eks.amazonaws.com/role-arn=arn:aws:iam::123456789012:role/EKS-Pod-Role

4. Establishing IAM Role Associations

Once the service account is annotated with the correct IAM role, any pod using this service account can automatically assume the permissions granted to the role. This makes it simple to manage access at the pod level, without needing to modify node-level permissions.

Behind the Scenes: How EKS Pod Identity Works

The magic of EKS Pod Identity lies in the integration between Kubernetes service accounts and AWS IAM roles via OIDC. The Pod Identity Webhook intercepts API calls from pods and validates the service account annotations. It then requests temporary credentials from AWS STS (Security Token Service) on behalf of the pod. These credentials are short-lived and scoped specifically to the permissions defined in the IAM role.

Benefits for EKS Administrators

1. Simplified Automation of IAM Roles

EKS Pod Identity simplifies the automation of IAM roles in Kubernetes clusters by eliminating the need for node-level role assignments. Pods automatically inherit the appropriate permissions based on their service account configuration, making it easier to manage complex environments.

2. AWS-Native Process

The EKS Pod Identity solution is fully AWS-native, leveraging AWS IAM, OIDC, and Kubernetes service accounts in a streamlined and secure manner. This tight integration reduces friction between cloud-native tools and enhances operational efficiency.

3. Enhanced Clarity of Pod Permissions

Rather than applying broad permissions to entire nodes, administrators can define fine-grained permissions for each pod. This increases the clarity of which services and resources each pod can access, improving security and minimizing the blast radius in the event of a breach.

4. Granular Control with Trust Relations

IAM role trust policies are flexible and can define the exact permissions required by pods. By using the OIDC provider and the Pod Identity Webhook, trust relationships are dynamically managed, reducing the need for manual intervention.

5. Mapping and Understanding Pod Permissions

Administrators can map IAM roles to Kubernetes service accounts with ease. This allows for easy auditing of pod permissions and a clear understanding of the access levels granted across your Kubernetes cluster.

Conclusion: Embracing the Future of Kubernetes Credential Management

AWS EKS Pod Identity represents a significant leap forward in Kubernetes credential management. It streamlines the process of assigning IAM roles to pods, improves security through granular access control, and enhances clarity around pod permissions. For Kubernetes administrators looking to embrace a more secure, automated, and AWS-native approach, EKS Pod Identity is the future.

References

Amazon EKS Pod Identity: a new way for applications on EKS to obtain IAM credentials

Amazon EKS Pod Identity simplifies IAM permissions for applications on Amazon EKS clusters.