ansible-eyc-inventory

#!/usr/bin/env ruby

require 'json'

Instance = Struct.new(:hostname, :amazon_id, :role)

def environment
  basename = File.basename(__FILE__)

  unless basename.include?('@')
    warn <<-EOF
Choose an EYC's environment as follows:

$ ln -s #{basename} #{__FILE__}@production
    EOF

    exit 1
  end

  basename.split('@', 2).last
end

def instances(environment)
  stdout = `ey servers --environment #{environment} --simple`

  exit 1 unless $?.success?

  stdout.lines.map {|line|
    Instance.new(*line.chomp.split)
  }
end

def hostvars(instances)
  instances.each_with_object({}) {|instance, memo|
    memo[instance.hostname] = {
      ansible_ssh_user: 'deploy',
      amazon_id:        instance.amazon_id
    }
  }
end

instances = instances(environment)

json = instances.group_by(&:role).each_with_object({}) {|(role, is), memo|
  memo[role] = {
    hosts: is.map(&:hostname)
  }
}.merge(
  _meta: {
    hostvars: hostvars(instances)
  }
)

puts JSON.pretty_generate(json)