Module: Fum::DNS

Included in:
Commands::Launch, Commands::List, Commands::Repair, Commands::Status, StageAnalyzer
Defined in:
lib/fum/dns.rb

Overview

Mixin for common DNS methods

Instance Method Summary collapse

Instance Method Details

#dns ⇒ Object 



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# File 'lib/fum/dns.rb', line 8

def dns
  Fog::DNS[:AWS]
end

#dns_names_equal(a, b) ⇒ Object

Returns true if the specified dns names equal, ignoring any trailing “.”



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# File 'lib/fum/dns.rb', line 130

def dns_names_equal(a, b)
  ensure_trailing_dot(a) == ensure_trailing_dot(b)
end

#ensure_trailing_dot(name) ⇒ Object

Appends a trailing . to the given name if it doesn’t have one



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# File 'lib/fum/dns.rb', line 124

def ensure_trailing_dot(name)
  name = "#{name}." unless name.nil? || name.end_with?(".")
  name
end

#find_records(zone, name) ⇒ Object 



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# File 'lib/fum/dns.rb', line 112

def find_records(zone, name)
  existing_records = zone.records.all({:name => name})

  matching = []
  types = ['A', 'AAAA', 'CNAME']
  existing_records.each { |record|
    matching << record if record.name == name && types.include?(record.type)
  }
  matching
end

#update_zone(zone_decl, hosted_zone_name_id, dns_name, env_cname, options) ⇒ Object 



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# File 'lib/fum/dns.rb', line 29

def update_zone(zone_decl, hosted_zone_name_id, dns_name, env_cname, options)
  dns = Fog::DNS[:aws]

  zone = dns.zones.all({:domain => zone_decl.name}).shift
  die "Could not find zone #{zone_decl.name} in account." unless zone

  puts "Updating records in zone #{zone.domain}"
  create_list = []
  modify_list = []

  zone_decl.records.each { |record|
    fqdn = "#{record[:name]}.#{zone_decl.name}."

    create_opts = {
        :name => fqdn,
        :type => record[:type]
    }

    case record[:type]
      when 'CNAME'
        create_opts[:value] = case record[:target]
                                when :elb
                                  ensure_trailing_dot(dns_name)
                                when :env
                                  ensure_trailing_dot(env_cname)
                              end
      when 'A'
        create_opts[:alias_target] = {
            :hosted_zone_id => hosted_zone_name_id,
            :dns_name => dns_name
        }
      else
        raise RuntimeError, "Unknown type #{record[:type]}"
    end

    existing = find_records(zone, fqdn)

    if existing.length > 1
      # We do not currently handle this case, which would occur if AAAA records exist or weighted/latency records used.
      puts "Cannot update record #{fqdn} in zone #{zone} because more than one A, AAAA, or CNAME record already exists."
    end

    if existing.length == 0
      create_list << create_opts
    else
      modify_list << {
          :record => existing.shift,
          :create_opts => create_opts
      }
    end

  }

  # We do not currently do this atomically, but one record at a time.  Should probably move to atomic at some
  # point.

  new_records = []

  create_list.each { |create_options|
    puts "Creating #{create_options[:type]} record with name #{create_options[:name]} in zone #{zone.domain}"
    unless options[:noop]
      new_records << zone.records.create(create_options)
    end
  }

  modify_list.each { |record|
    puts "Updating #{record[:create_opts][:type]} record with name #{record[:create_opts][:name]} in zone #{zone.domain}"
    unless options[:noop]
      record[:record].modify(record[:create_opts])
      new_records << record[:record]
    end
  }

  puts "Waiting for DNS records to sync in zone #{zone.domain}..."
  # Wait for records to be ready.
  new_records.each { |record|
    record.wait_for { record.ready? }
  }
  puts "Updated records are now in sync in zone #{zone.domain}"

end

#update_zones(stage_decl, env, options) ⇒ Object 



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# File 'lib/fum/dns.rb', line 12

def update_zones(stage_decl, env, options)
  zones = stage_decl.zones

  hosted_zone_name_id = nil
  dns_name = nil

  unless options[:noop]
    lb = env.load_balancer

    hosted_zone_name_id = lb.hosted_zone_name_id
    dns_name = lb.dns_name
  end

  zones.each { |zone| update_zone(zone, hosted_zone_name_id, dns_name, env.cname, options) }

end