aws-iam-authenticator

The aws-iam-authenticator tool addresses the critical security and operational challenge of securely authenticating users to Kubernetes clusters using AWS IAM credentials. This is particularly important in environments where access control and identity management are stringent.

Technically, the tool leverages the AWS sts:GetCallerIdentity API endpoint to verify the identity of users. It works by generating and pre-signing a request to this endpoint, which is then serialized into a token that can be passed through the Kubernetes authentication system. This process is facilitated by running the aws-iam-authenticator server as a DaemonSet within the Kubernetes cluster, and configuring the API server to communicate with this authenticator.

Operationally, the setup involves creating an IAM role to identify users, configuring the kubeconfig to use the aws-iam-authenticator command, and ensuring the binary is installed and accessible. The kubeconfig can be shared across users, but it is recommended to store it in a trusted location such as AWS S3. Environment variables, such as the AWS profile, can be set within the kubeconfig to ensure the correct profile is used implicitly.

Key operational considerations include ensuring the correct version of the aws-iam-authenticator binary is installed, as version mismatches can lead to issues like the one described in the kops deployment problem where image tags were not found in the registry. Additionally, the tool's configuration must be carefully managed to prevent replay attacks, using unique cluster identifiers and default IAM roles as necessary.

From a technical details perspective, the tool supports various architectures including amd64 and arm64, and it is built using Go, which is a requirement for building the tool from source. The current stable version is 0.6.28, and it is widely supported across different platforms.