one liner: generate prefix list array from aws ip range json

ip_ranges2prefix_list.rb

# https://docs.aws.amazon.com/ja_jp/general/latest/gr/aws-ip-ranges.html#aws-ip-egress-control

# requirements
# - curl
# - jq

require 'json'
require 'yaml'

REGION='ap-northeast-1'

iprange_strings = `curl https://ip-ranges.amazonaws.com/ip-ranges.json | jq -r '[.prefixes[] | select(.service=="AMAZON" and .region=="#{REGION}").ip_prefix] - [.prefixes[] | select(.service=="EC2").ip_prefix] | .[]'`
ipranges = iprange_strings.split("\n")

result = ipranges.map do |cidr|
  puts cidr
  { "Cidr" => cidr }
end

puts "json version"
puts result.to_json

puts "yaml version"
puts result.to_yaml