Module: Bosh::Director::DnsHelper

Included in:
Api::Controllers::BaseController, Config, Bosh::Director::DeploymentPlan::Assembler, Bosh::Director::DeploymentPlan::DynamicNetwork, Bosh::Director::DeploymentPlan::Instance, Bosh::Director::DeploymentPlan::Job, Bosh::Director::DeploymentPlan::ManualNetwork, Bosh::Director::DeploymentPlan::Network, Bosh::Director::DeploymentPlan::NetworkSubnet, Bosh::Director::DeploymentPlan::Planner, InstanceDeleter, InstanceUpdater, Jobs::DeleteDeployment
Defined in:
lib/bosh/director/dns_helper.rb

Constant Summary collapse

SOA =

primary_ns contact serial refresh retry expire minimum

"localhost hostmaster@localhost 0 10800 604800 30"
TTL_5M = 
300
TTL_4H = 
3600 * 4

Instance Method Summary collapse

Instance Method Details

#add_default_dns_server(servers) ⇒ Object

add default dns server to an array of dns servers



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# File 'lib/bosh/director/dns_helper.rb', line 65

def add_default_dns_server(servers)
  return servers unless Config.dns_enabled?

  default_server = default_dns_server
  if default_server && default_server != "127.0.0.1"
    (servers ||= []) << default_server
    servers.uniq!
  end

  servers
end

#canonical(string) ⇒ Object 



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# File 'lib/bosh/director/dns_helper.rb', line 23

def canonical(string)
  # a-z, 0-9, -, case insensitive, and must start with a letter
  string = string.downcase.gsub(/_/, "-").gsub(/[^a-z0-9-]/, "")
  if string =~ /^(\d|-)/
    raise DnsInvalidCanonicalName,
          "Invalid DNS canonical name `#{string}', must begin with a letter"
  end
  if string =~ /-$/
    raise DnsInvalidCanonicalName,
          "Invalid DNS canonical name `#{string}', can't end with a hyphen"
  end
  string
end

#default_dns_server ⇒ Object

returns the default DNS server



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# File 'lib/bosh/director/dns_helper.rb', line 60

def default_dns_server
  Config.dns["server"] if Config.dns
end

#delete_dns_records(record_pattern, domain_id = nil) ⇒ Object

deletes all DNS records matching the pattern

Parameters:

  • record_pattern (String) —

    SQL pattern

  • domain_id (Integer) (defaults to: nil) —

    domain record id



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# File 'lib/bosh/director/dns_helper.rb', line 145

def delete_dns_records(record_pattern, domain_id=nil)
  records = Models::Dns::Record.filter(:name.like(record_pattern))
  if domain_id
    records = records.filter(:domain_id => domain_id)
  end

  # delete A records and collect all IPs for later
  ips = []
  records.each do |record|
    ips << record.content
    @logger.info("Deleting DNS record: #{record.name}")
    record.destroy
  end

  # delete PTR records from IP list
  ips.each do |ip|
    records = Models::Dns::Record.filter(:name.like(reverse_host(ip)))
    records.each do |record|
      @logger.info("Deleting reverse DNS record: #{record.name}")
      record.destroy
    end
  end

  # see if any of the reverse domains are empty and should be deleted
  ips.each do |ip|
    reverse = reverse_domain(ip)
    rdomain = Models::Dns::Domain.filter(:name => reverse,
                                         :type => "NATIVE")
    rdomain.each do |domain|
      delete_empty_domain(domain)
    end
  end
end

#delete_empty_domain(domain) ⇒ Object

if the count is 2, it means we only have the NS & SOA record and the domain is “empty” and can be deleted



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# File 'lib/bosh/director/dns_helper.rb', line 181

def delete_empty_domain(domain)
  if domain.records.size == 2
    @logger.info("Deleting empty reverse domain #{domain.name}")
    domain.destroy # cascaded - all records are removed
  end
end

#dns_domain_name ⇒ Object

returns the DNS domain name



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# File 'lib/bosh/director/dns_helper.rb', line 78

def dns_domain_name
  Config.dns_domain_name
end

#dns_ns_record ⇒ Object

returns the DNS name server record



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# File 'lib/bosh/director/dns_helper.rb', line 83

def dns_ns_record
  "ns.#{dns_domain_name}"
end

#dns_servers(network, spec, add_default_dns = true) ⇒ Object

build a list of dns servers to use



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# File 'lib/bosh/director/dns_helper.rb', line 38

def dns_servers(network, spec, add_default_dns = true)
  servers = nil
  dns_property = safe_property(spec, "dns",
                               :class => Array, :optional => true)
  if dns_property
    servers = []
    dns_property.each do |dns|
      dns = NetAddr::CIDR.create(dns)
      unless dns.size == 1
        invalid_dns(network, "must be a single IP")
      end

      servers << dns.ip
    end
  end

  return servers unless add_default_dns

  add_default_dns_server(servers)
end

#invalid_dns(network, reason) ⇒ Object

Parameters:

  • network (String) —

    name

  • reason (String)

Raises:

  • NetworkInvalidDns



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# File 'lib/bosh/director/dns_helper.rb', line 191

def invalid_dns(network, reason)
  raise NetworkInvalidDns,
        "Invalid DNS for network `#{network}': #{reason}"
end

#reverse_domain(ip) ⇒ String

Returns reverse dns domain name for an IP.

Parameters:

  • ip (String) —

    IP address

Returns:

  • (String) —

    reverse dns domain name for an IP



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# File 'lib/bosh/director/dns_helper.rb', line 13

def reverse_domain(ip)
  reverse(ip, 2)
end

#reverse_host(ip) ⇒ String

Returns reverse dns name for an IP used for a PTR record.

Parameters:

  • ip (String) —

    IP address

Returns:

  • (String) —

    reverse dns name for an IP used for a PTR record



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# File 'lib/bosh/director/dns_helper.rb', line 19

def reverse_host(ip)
  reverse(ip, 3)
end

#update_dns_a_record(domain, name, ip_address) ⇒ Object

create/update DNS A record



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# File 'lib/bosh/director/dns_helper.rb', line 88

def update_dns_a_record(domain, name, ip_address)
  record = Models::Dns::Record.find(:domain_id => domain.id,
                                    :name => name)
  if record.nil?
    record = Models::Dns::Record.new(:domain_id => domain.id,
                                     :name => name, :type => "A",
                                     :ttl => TTL_5M)
  end
  record.content = ip_address
  record.change_date = Time.now.to_i
  record.save
end

#update_dns_ptr_record(name, ip_address) ⇒ Object

create/update DNS PTR records (for reverse lookups)



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# File 'lib/bosh/director/dns_helper.rb', line 102

def update_dns_ptr_record(name, ip_address)
  reverse_domain = reverse_domain(ip_address)
  reverse_host = reverse_host(ip_address)

  rdomain = Models::Dns::Domain.safe_find_or_create(:name => reverse_domain,
                                                    :type => "NATIVE")
  Models::Dns::Record.find_or_create(:domain_id => rdomain.id,
                                     :name => reverse_domain,
                                     :type =>'SOA', :content => SOA,
                                     :ttl => TTL_4H)

  Models::Dns::Record.find_or_create(:domain_id => rdomain.id,
                                     :name => reverse_domain,
                                     :type =>'NS', :ttl => TTL_4H,
                                     :content => dns_ns_record)

  record = Models::Dns::Record.find(:content => name, :type =>'PTR')

  # delete the record if the IP address changed
  if record && record.name != reverse_host
    id = record.domain_id
    record.destroy
    record = nil

    # delete the domain if the domain id changed and it's empty
    if id != rdomain.id
      delete_empty_domain(Models::Dns::Domain[id])
    end
  end

  unless record
    record = Models::Dns::Record.new(:domain_id => rdomain.id,
                                     :name => reverse_host,
                                     :type =>'PTR', :ttl => TTL_5M)
  end
  record.content = name
  record.change_date = Time.now.to_i
  record.save
end