Convert a BOSH manifest using Static IP networks into using DHCP "dynamic" networking + DNS hostnames - extracted from bosh-workspace

manifest_use_dns.rb

#!/usr/bin/env ruby


manifest = ARGV[0]
domain_name = ARGV[1] || "microbosh"

def err(msg)
  $stderr.puts(msg)
  exit 1
end

unless manifest && File.exist?(manifest)
  err "USAGE: manifest_use_dns.rb path/to/manifest.rb microbosh"
end

require "yaml"
class DnsHelper
  def self.transform(generated_manifest, domain_name)
    @manifest = YAML.load(IO.read(generated_manifest))
    @domain_name = domain_name
    @manual_networks = []
    @dns = {}

    transform_networks

    if @manual_networks.empty?
      err "Missing manual network: Only type manual can be transformed to dynamic"
    end

    transform_jobs
    transform_properties
    transform_job_properties

    IO.write(generated_manifest, @manifest.to_yaml)
  end

  private

  def self.transform_networks
    @manifest["networks"].map! do |network|
      if network["type"] == "manual"
        @manual_networks << network["name"]
        { "name" => network["name"], "type" => "dynamic", "cloud_properties" => {} }
      else
        network
      end
    end
  end

  def self.transform_jobs
    @manifest["jobs"].map! do |job|
      job["networks"].map! do |network|
        if @manual_networks.include?(network["name"]) && network["static_ips"]
          network["static_ips"].each_with_index do |ip, index|
            @dns[ip] = job_to_dns(job, index, network["name"])
          end
          network.delete("static_ips")
        end
        network
      end
      job
    end
  end

  def self.transform_properties
    @manifest["properties"] = replace_ips(@manifest["properties"])
  end

  def self.transform_job_properties
    @manifest["jobs"].map! do |job|
      job["properties"] = replace_ips(job["properties"]) if job["properties"]
      job
    end
  end

  def self.job_to_dns(job, index, network_name)
    job_name = job["name"].gsub('_', '-')
    [index, job_name, network_name, @manifest["name"], @domain_name].join(".")
  end

  def self.replace_ips(properties)
    properties_yaml = properties.to_yaml
    @dns.each { |ip, domain| properties_yaml.gsub!(ip, domain) }
    YAML.load properties_yaml
  end
end

DnsHelper.transform(manifest, domain_name)