List all AWS IAM Users of an account

list_aws_iam_users.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'aws-sdk'
require 'highline/import'

def get_aws_account_data(iam)
  begin
    iam = iam.client.get_user
    id, user = iam[:user][:arn].match('^arn:aws:iam::([0-9]{12}):(.*)$').captures
  rescue AWS::IAM::Errors::AccessDenied
      result = $!
      id, user = result.to_s.match('^User: arn:aws:iam::([0-9]{12}):(.*) is not auth.*$').captures
  end
  raise 'incorrect account id' unless id.match(/^[0-9]{12}$/)
  [id, user]
end

access_key_id = ARGV[0].nil? ? ask("AWS Access Key ID: ") : ARGV[0]
secret_access_key = ARGV[1].nil? ? ask("AWS Secret Access Key: ") { |q| q.echo = false } : ARGV[1]

iam = AWS::IAM.new(:access_key_id => access_key_id,
                   :secret_access_key => secret_access_key)

acc = get_aws_account_data(iam)
sum = iam.account_summary

puts "*** Listing #{sum[:users]} users for AWS Acc ID #{acc[0]} (as #{acc[1]})"

iam.users.each do |user|
  puts "\n#{user.path}#{user.name} (#{user.arn})"
  user.access_keys.each do |key|
    puts "- Access Key ID: #{key.id} (#{key.status})"
  end
end