aws-whoami

#!/usr/bin/env bash

command_exists() {
  type "${1}" >/dev/null 2>&1
}

ensure_command() {
  if ! command_exists "${1}"; then
    echo "command not found: ${1}"
    exit 1
  fi
}

aws_whoami() {
  local -r identity_blob="$(aws sts get-caller-identity --output=json)"
  local -r account_aliases_blob="$(aws iam list-account-aliases --max-items=1 2>/dev/null || echo '{"AccountAliases":["N/A"]}')"

  local -r account_alias="$(echo "${account_aliases_blob}" | jq -r '.AccountAliases[0]')"
  local -r account_id="$(echo "${identity_blob}" | jq -r '.Account')"
  local -r user_id="$(echo "${identity_blob}" | jq -r '.UserId')"
  local -r arn="$(echo "${identity_blob}" | jq -r '.Arn')"

  echo "Account Alias : ${account_alias}"
  echo "   Account ID : ${account_id}"
  echo "      User ID : ${user_id}"
  echo "          ARN : ${arn}"
}

ensure_command aws
ensure_command jq

aws_whoami