AWS IAM Get UserName by Access Key Id

aws-iam-get-username-by-access-key.bash

#!/bin/bash

# exit when the command fails
set -o errexit;

# exit when try to use undeclared var
set -o nounset;

accessKeyToSearch=${1?"Usage: bash $0 AccessKeyId"}

for username in $(aws iam list-users --query 'Users[*].UserName' --output text); do
	for accessKeyId in $(aws iam list-access-keys --user-name $username --query 'AccessKeyMetadata[*].AccessKeyId' --output text); do
		if [ "$accessKeyToSearch" = "$accessKeyId" ]; then
			echo $username;
			break;
		fi;
	done;
done;