gitlab-org--gitlab-foss/spec/lib/gitlab/database/load_balancing/resolver_spec.rb

80 lines
2.6 KiB
Ruby

# frozen_string_literal: true
require 'spec_helper'
RSpec.describe Gitlab::Database::LoadBalancing::Resolver do
describe '#resolve' do
let(:ip_addr) { IPAddr.new('127.0.0.2') }
context 'when nameserver is an IP' do
it 'returns an IPAddr object' do
service = described_class.new('127.0.0.2')
expect(service.resolve).to eq(ip_addr)
end
end
context 'when nameserver is not an IP' do
subject { described_class.new('localhost').resolve }
it 'looks the nameserver up in the hosts file' do
allow_next_instance_of(Resolv::Hosts) do |instance|
allow(instance).to receive(:getaddress).with('localhost').and_return('127.0.0.2')
end
expect(subject).to eq(ip_addr)
end
context 'when nameserver is not in the hosts file' do
it 'looks the nameserver up in DNS' do
resource = double(:resource, address: ip_addr)
packet = double(:packet, answer: [resource])
allow_next_instance_of(Resolv::Hosts) do |instance|
allow(instance).to receive(:getaddress).with('localhost').and_raise(Resolv::ResolvError)
end
allow(Net::DNS::Resolver).to receive(:start)
.with('localhost', Net::DNS::A)
.and_return(packet)
expect(subject).to eq(ip_addr)
end
context 'when nameserver is not in DNS' do
it 'raises an exception' do
allow_next_instance_of(Resolv::Hosts) do |instance|
allow(instance).to receive(:getaddress).with('localhost').and_raise(Resolv::ResolvError)
end
allow(Net::DNS::Resolver).to receive(:start)
.with('localhost', Net::DNS::A)
.and_return(double(:packet, answer: []))
expect { subject }.to raise_exception(
described_class::UnresolvableNameserverError,
'could not resolve localhost'
)
end
end
context 'when DNS does not respond' do
it 'raises an exception' do
allow_next_instance_of(Resolv::Hosts) do |instance|
allow(instance).to receive(:getaddress).with('localhost').and_raise(Resolv::ResolvError)
end
allow(Net::DNS::Resolver).to receive(:start)
.with('localhost', Net::DNS::A)
.and_raise(Net::DNS::Resolver::NoResponseError)
expect { subject }.to raise_exception(
described_class::UnresolvableNameserverError,
'no response from DNS server(s)'
)
end
end
end
end
end
end