opsworks_config_generator.rb

require "rubygems"
require "aws-sdk"
require "pry-nav"

opsworks = Aws::OpsWorks::Client.new(
  region: "us-east-1"
)

TrueInstance = Struct.new(:hostname, :private_ip, :layer, :stack)

true_instances = []

stacks = opsworks.describe_stacks.stacks

stacks.each do |stack|
  layers = opsworks.describe_layers({ stack_id: stack.stack_id }).layers

  layers.each do |layer|
    instances = opsworks.describe_instances({ layer_id: layer.layer_id }).instances

    instances.each do |instance|
      unless instance.private_ip.nil?
        true_instances << TrueInstance.new(instance.hostname, instance.private_ip, layer.name, stack.name)
      end
    end
  end
end

true_instances.sort!{|a, b| a.hostname <=> b.hostname }

File.open("config", "w") do |f|
  true_instances.each do |instance|
    f.write("# Project #{instance.stack}\n")
    f.write("# Layer #{instance.layer}\n")
    f.write("Host #{instance.hostname}\n")
    f.write("\s\sHostName #{instance.private_ip}\n")
    f.write("\s\sPort 22\n")
    f.write("\s\sUser ubuntu\n")
    f.write("\s\sIdentityFile ~/.ssh/opsworks.pem\n")
    f.write("\n")
  end
end