53 lines
1.2 KiB
Ruby
53 lines
1.2 KiB
Ruby
# frozen_string_literal: true
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require 'net/dns'
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require 'resolv'
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module Gitlab
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module Database
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module LoadBalancing
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class Resolver
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UnresolvableNameserverError = Class.new(StandardError)
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def initialize(nameserver)
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@nameserver = nameserver
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end
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def resolve
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address = ip_address || ip_address_from_hosts_file ||
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ip_address_from_dns
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unless address
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raise UnresolvableNameserverError,
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"could not resolve #{@nameserver}"
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end
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address
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end
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private
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def ip_address
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IPAddr.new(@nameserver)
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rescue IPAddr::InvalidAddressError
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end
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def ip_address_from_hosts_file
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ip = Resolv::Hosts.new.getaddress(@nameserver)
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IPAddr.new(ip)
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rescue Resolv::ResolvError
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end
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def ip_address_from_dns
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answer = Net::DNS::Resolver.start(@nameserver, Net::DNS::A).answer
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return if answer.empty?
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answer.first.address
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rescue Net::DNS::Resolver::NoResponseError
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raise UnresolvableNameserverError, "no response from DNS server(s)"
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end
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end
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end
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end
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end
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