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require 'spec_helper'
require 'puppet/http'
describe Puppet::HTTP::DNS do
before do
@dns_mock_object = double('dns')
allow(Resolv::DNS).to receive(:new).and_return(@dns_mock_object)
@rr_type = Resolv::DNS::Resource::IN::SRV
@test_srv_domain = "domain.com"
@test_a_hostname = "puppet.domain.com"
@test_port = 1000
# The records we should use.
@test_records = [
# priority, weight, port, target
Resolv::DNS::Resource::IN::SRV.new(0, 20, 8140, "puppet1.domain.com"),
Resolv::DNS::Resource::IN::SRV.new(0, 80, 8140, "puppet2.domain.com"),
Resolv::DNS::Resource::IN::SRV.new(1, 1, 8140, "puppet3.domain.com"),
Resolv::DNS::Resource::IN::SRV.new(4, 1, 8140, "puppet4.domain.com")
]
@test_records.each do |rec|
# Resources do not expose public API for setting the TTL
rec.instance_variable_set(:@ttl, 3600)
end
end
let(:resolver) { described_class.new }
describe 'when the domain is not known' do
before :each do
allow(@dns_mock_object).to receive(:getresources).and_return(@test_records)
end
describe 'because domain is nil' do
it 'does not yield' do
resolver.each_srv_record(nil) do |_,_,_|
raise Exception.new("nil domain caused SRV lookup")
end
end
end
describe 'because domain is an empty string' do
it 'does not yield' do
resolver.each_srv_record('') do |_,_,_|
raise Exception.new("nil domain caused SRV lookup")
end
end
end
end
describe "when resolving a host without SRV records" do
it "should not yield anything" do
# No records returned for a DNS entry without any SRV records
expect(@dns_mock_object).to receive(:getresources).with(
"_x-puppet._tcp.#{@test_a_hostname}",
@rr_type
).and_return([])
resolver.each_srv_record(@test_a_hostname) do |hostname, port, remaining|
raise Exception.new("host with no records passed block")
end
end
end
describe "when resolving a host with SRV records" do
it "should iterate through records in priority order" do
# The order of the records that should be returned,
# an array means unordered (for weight)
order = {
0 => ["puppet1.domain.com", "puppet2.domain.com"],
1 => ["puppet3.domain.com"],
2 => ["puppet4.domain.com"]
}
expect(@dns_mock_object).to receive(:getresources).with(
"_x-puppet._tcp.#{@test_srv_domain}",
@rr_type
).and_return(@test_records)
resolver.each_srv_record(@test_srv_domain) do |hostname, port|
expected_priority = order.keys.min
expect(order[expected_priority]).to include(hostname)
expect(port).not_to be(@test_port)
# Remove the host from our expected hosts
order[expected_priority].delete hostname
# Remove this priority level if we're done with it
order.delete expected_priority if order[expected_priority] == []
end
end
it "should fall back to the :puppet service if no records are found for a more specific service" do
# The order of the records that should be returned,
# an array means unordered (for weight)
order = {
0 => ["puppet1.domain.com", "puppet2.domain.com"],
1 => ["puppet3.domain.com"],
2 => ["puppet4.domain.com"]
}
expect(@dns_mock_object).to receive(:getresources).with(
"_x-puppet-report._tcp.#{@test_srv_domain}",
@rr_type
).and_return([])
expect(@dns_mock_object).to receive(:getresources).with(
"_x-puppet._tcp.#{@test_srv_domain}",
@rr_type
).and_return(@test_records)
resolver.each_srv_record(@test_srv_domain, :report) do |hostname, port|
expected_priority = order.keys.min
expect(order[expected_priority]).to include(hostname)
expect(port).not_to be(@test_port)
# Remove the host from our expected hosts
order[expected_priority].delete hostname
# Remove this priority level if we're done with it
order.delete expected_priority if order[expected_priority] == []
end
end
it "should use SRV records from the specific service if they exist" do
# The order of the records that should be returned,
# an array means unordered (for weight)
order = {
0 => ["puppet1.domain.com", "puppet2.domain.com"],
1 => ["puppet3.domain.com"],
2 => ["puppet4.domain.com"]
}
bad_records = [
# priority, weight, port, hostname
Resolv::DNS::Resource::IN::SRV.new(0, 20, 8140, "puppet1.bad.domain.com"),
Resolv::DNS::Resource::IN::SRV.new(0, 80, 8140, "puppet2.bad.domain.com"),
Resolv::DNS::Resource::IN::SRV.new(1, 1, 8140, "puppet3.bad.domain.com"),
Resolv::DNS::Resource::IN::SRV.new(4, 1, 8140, "puppet4.bad.domain.com")
]
expect(@dns_mock_object).to receive(:getresources).with(
"_x-puppet-report._tcp.#{@test_srv_domain}",
@rr_type
).and_return(@test_records)
allow(@dns_mock_object).to receive(:getresources).with(
"_x-puppet._tcp.#{@test_srv_domain}",
@rr_type
).and_return(bad_records)
resolver.each_srv_record(@test_srv_domain, :report) do |hostname, port|
expected_priority = order.keys.min
expect(order[expected_priority]).to include(hostname)
expect(port).not_to be(@test_port)
# Remove the host from our expected hosts
order[expected_priority].delete hostname
# Remove this priority level if we're done with it
order.delete expected_priority if order[expected_priority] == []
end
end
end
describe "when finding weighted servers" do
it "should return nil when no records were found" do
expect(resolver.find_weighted_server([])).to eq(nil)
end
it "should return the first record when one record is passed" do
result = resolver.find_weighted_server([@test_records.first])
expect(result).to eq(@test_records.first)
end
{
"all have weights" => [1, 3, 2, 4],
"some have weights" => [2, 0, 1, 0],
"none have weights" => [0, 0, 0, 0],
}.each do |name, weights|
it "should return correct results when #{name}" do
records = []
count = 0
weights.each do |w|
count += 1
# priority, weight, port, server
records << Resolv::DNS::Resource::IN::SRV.new(0, w, 1, count.to_s)
end
seen = Hash.new(0)
total_weight = records.inject(0) do |sum, record|
sum + resolver.weight(record)
end
total_weight.times do |n|
expect(Kernel).to receive(:rand).once.with(total_weight).and_return(n)
server = resolver.find_weighted_server(records)
seen[server] += 1
end
expect(seen.length).to eq(records.length)
records.each do |record|
expect(seen[record]).to eq(resolver.weight(record))
end
end
end
end
describe "caching records" do
it "should query DNS when no cache entry exists, then retrieve the cached value" do
expect(@dns_mock_object).to receive(:getresources).with(
"_x-puppet._tcp.#{@test_srv_domain}",
@rr_type
).and_return(@test_records).once
fetched_servers = []
resolver.each_srv_record(@test_srv_domain) do |server, port|
fetched_servers << server
end
cached_servers = []
expect(resolver).to receive(:expired?).and_return(false)
resolver.each_srv_record(@test_srv_domain) do |server, port|
cached_servers << server
end
expect(fetched_servers).to match_array(cached_servers)
end
context "TTLs" do
before(:each) do
# The TTL of an SRV record cannot be set via any public API
ttl_record1 = Resolv::DNS::Resource::IN::SRV.new(0, 20, 8140, "puppet1.domain.com")
ttl_record1.instance_variable_set(:@ttl, 10)
ttl_record2 = Resolv::DNS::Resource::IN::SRV.new(0, 20, 8140, "puppet2.domain.com")
ttl_record2.instance_variable_set(:@ttl, 20)
records = [ttl_record1, ttl_record2]
expect(@dns_mock_object).to receive(:getresources).with(
"_x-puppet._tcp.#{@test_srv_domain}",
@rr_type
).and_return(records)
end
it "should save the shortest TTL among records for a service" do
resolver.each_srv_record(@test_srv_domain) { |server, port| }
expect(resolver.ttl(:puppet)).to eq(10)
end
it "should fetch records again if the TTL has expired" do
# Fetch from DNS
resolver.each_srv_record(@test_srv_domain) do |server, port|
expect(server).to match(/puppet.*domain\.com/)
end
expect(resolver).to receive(:expired?).with(:puppet).and_return(false)
# Load from cache
resolver.each_srv_record(@test_srv_domain) do |server, port|
expect(server).to match(/puppet.*domain\.com/)
end
new_record = Resolv::DNS::Resource::IN::SRV.new(0, 20, 8140, "new.domain.com")
new_record.instance_variable_set(:@ttl, 10)
expect(@dns_mock_object).to receive(:getresources).with(
"_x-puppet._tcp.#{@test_srv_domain}",
@rr_type
).and_return([new_record])
expect(resolver).to receive(:expired?).with(:puppet).and_return(true)
# Refresh from DNS
resolver.each_srv_record(@test_srv_domain) do |server, port|
expect(server).to eq("new.domain.com")
end
end
end
end
end
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