49 lines
1.4 KiB
Ruby
49 lines
1.4 KiB
Ruby
# frozen_string_literal: true
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require 'net/dns'
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module Gitlab
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module Database
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module LoadBalancing
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# Hostnames returned in SRV records cannot sometimes be resolved by a local
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# resolver, however, there's a possibility that their A/AAAA records are
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# returned as part of the SRV query in the additional section, so we try
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# to extract the IPs from there first, failing back to querying the
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# hostnames A/AAAA records one by one, using the same resolver that
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# queried the SRV record.
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class SrvResolver
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include Gitlab::Utils::StrongMemoize
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attr_reader :resolver, :additional
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def initialize(resolver, additional)
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@resolver = resolver
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@additional = additional
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end
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def address_for(host)
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addresses_from_additional[host] || resolve_host(host)
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end
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private
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def addresses_from_additional
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strong_memoize(:addresses_from_additional) do
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additional.each_with_object({}) do |rr, h|
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h[rr.name] = rr.address if rr.is_a?(Net::DNS::RR::A) || rr.is_a?(Net::DNS::RR::AAAA)
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end
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end
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end
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def resolve_host(host)
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record = resolver.search(host, Net::DNS::ANY).answer.find do |rr|
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rr.is_a?(Net::DNS::RR::A) || rr.is_a?(Net::DNS::RR::AAAA)
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end
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record&.address
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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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