count_security_groups.rb

#!/usr/bin/env ruby

require 'json'
require 'aws-sdk-ec2'

ec2 = Aws::EC2::Client.new


res = ec2.describe_security_groups
security_groups = res.security_groups

puts "### Number of Security Groups of the Region"
puts
puts security_groups.size
puts
puts "---"
puts
puts "### Number of Incoming Security Group Rules per Security Group"
puts
puts " Security Group | Number of Rules"
puts "----------|-------:"
security_groups.each do |sg|
  count = 0
  sg.ip_permissions.each do |p|
    count += p.ip_ranges.size
  end
  puts "#{sg.group_id} | #{count}"
end
puts
puts "---"
puts
puts "### Number of Security Groups per ENI"
puts
res = ec2.describe_network_interfaces
network_interfaces = res.network_interfaces
puts "ENI | Number of SGs"
puts "--- | ------------:"
network_interfaces.each do |ni|
  puts "#{ni.network_interface_id} | #{ni.groups.size}"
end