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Diffstat (limited to 'spec/net_resolvers_service_spec.lua')
| -rw-r--r-- | spec/net_resolvers_service_spec.lua | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/spec/net_resolvers_service_spec.lua b/spec/net_resolvers_service_spec.lua new file mode 100644 index 00000000..53ce4754 --- /dev/null +++ b/spec/net_resolvers_service_spec.lua @@ -0,0 +1,241 @@ +local set = require "util.set"; + +insulate("net.resolvers.service", function () + local adns = { + resolver = function () + return { + lookup = function (_, cb, qname, qtype, qclass) + if qname == "_xmpp-server._tcp.example.com" + and (qtype or "SRV") == "SRV" + and (qclass or "IN") == "IN" then + cb({ + { -- 60+35+60 + srv = { target = "xmpp0-a.example.com", port = 5228, priority = 0, weight = 60 }; + }; + { + srv = { target = "xmpp0-b.example.com", port = 5216, priority = 0, weight = 35 }; + }; + { + srv = { target = "xmpp0-c.example.com", port = 5200, priority = 0, weight = 0 }; + }; + { + srv = { target = "xmpp0-d.example.com", port = 5256, priority = 0, weight = 120 }; + }; + + { + srv = { target = "xmpp1-a.example.com", port = 5273, priority = 1, weight = 30 }; + }; + { + srv = { target = "xmpp1-b.example.com", port = 5274, priority = 1, weight = 30 }; + }; + + { + srv = { target = "xmpp2.example.com", port = 5275, priority = 2, weight = 0 }; + }; + }); + elseif qname == "_xmpp-server._tcp.single.example.com" + and (qtype or "SRV") == "SRV" + and (qclass or "IN") == "IN" then + cb({ + { + srv = { target = "xmpp0-a.example.com", port = 5269, priority = 0, weight = 0 }; + }; + }); + elseif qname == "_xmpp-server._tcp.half.example.com" + and (qtype or "SRV") == "SRV" + and (qclass or "IN") == "IN" then + cb({ + { + srv = { target = "xmpp0-a.example.com", port = 5269, priority = 0, weight = 0 }; + }; + { + srv = { target = "xmpp0-b.example.com", port = 5270, priority = 0, weight = 1 }; + }; + }); + elseif qtype == "A" then + local l = qname:match("%-(%a)%.example.com$") or "1"; + local d = ("%d"):format(l:byte()) + cb({ + { + a = "127.0.0."..d; + }; + }); + elseif qtype == "AAAA" then + local l = qname:match("%-(%a)%.example.com$") or "1"; + local d = ("%04d"):format(l:byte()) + cb({ + { + aaaa = "fdeb:9619:649e:c7d9::"..d; + }; + }); + else + cb(nil); + end + end; + }; + end; + }; + package.loaded["net.adns"] = mock(adns); + local resolver = require "net.resolvers.service"; + math.randomseed(os.time()); + it("works for 99% of deployments", function () + -- Most deployments only have a single SRV record, let's make + -- sure that works okay + + local expected_targets = set.new({ + -- xmpp0-a + "tcp4 127.0.0.97 5269"; + "tcp6 fdeb:9619:649e:c7d9::0097 5269"; + }); + local received_targets = set.new({}); + + local r = resolver.new("single.example.com", "xmpp-server"); + local done = false; + local function handle_target(...) + if ... == nil then + done = true; + -- No more targets + return; + end + received_targets:add(table.concat({ ... }, " ", 1, 3)); + end + r:next(handle_target); + while not done do + r:next(handle_target); + end + + -- We should have received all expected targets, and no unexpected + -- ones: + assert.truthy(set.xor(received_targets, expected_targets):empty()); + end); + + it("supports A/AAAA fallback", function () + -- Many deployments don't have any SRV records, so we should + -- fall back to A/AAAA records instead when that is the case + + local expected_targets = set.new({ + -- xmpp0-a + "tcp4 127.0.0.97 5269"; + "tcp6 fdeb:9619:649e:c7d9::0097 5269"; + }); + local received_targets = set.new({}); + + local r = resolver.new("xmpp0-a.example.com", "xmpp-server", "tcp", { default_port = 5269 }); + local done = false; + local function handle_target(...) + if ... == nil then + done = true; + -- No more targets + return; + end + received_targets:add(table.concat({ ... }, " ", 1, 3)); + end + r:next(handle_target); + while not done do + r:next(handle_target); + end + + -- We should have received all expected targets, and no unexpected + -- ones: + assert.truthy(set.xor(received_targets, expected_targets):empty()); + end); + + + it("works", function () + local expected_targets = set.new({ + -- xmpp0-a + "tcp4 127.0.0.97 5228"; + "tcp6 fdeb:9619:649e:c7d9::0097 5228"; + "tcp4 127.0.0.97 5273"; + "tcp6 fdeb:9619:649e:c7d9::0097 5273"; + + -- xmpp0-b + "tcp4 127.0.0.98 5274"; + "tcp6 fdeb:9619:649e:c7d9::0098 5274"; + "tcp4 127.0.0.98 5216"; + "tcp6 fdeb:9619:649e:c7d9::0098 5216"; + + -- xmpp0-c + "tcp4 127.0.0.99 5200"; + "tcp6 fdeb:9619:649e:c7d9::0099 5200"; + + -- xmpp0-d + "tcp4 127.0.0.100 5256"; + "tcp6 fdeb:9619:649e:c7d9::0100 5256"; + + -- xmpp2 + "tcp4 127.0.0.49 5275"; + "tcp6 fdeb:9619:649e:c7d9::0049 5275"; + + }); + local received_targets = set.new({}); + + local r = resolver.new("example.com", "xmpp-server"); + local done = false; + local function handle_target(...) + if ... == nil then + done = true; + -- No more targets + return; + end + received_targets:add(table.concat({ ... }, " ", 1, 3)); + end + r:next(handle_target); + while not done do + r:next(handle_target); + end + + -- We should have received all expected targets, and no unexpected + -- ones: + assert.truthy(set.xor(received_targets, expected_targets):empty()); + end); + + it("balances across weights correctly #slow", function () + -- This mimics many repeated connections to 'example.com' (mock + -- records defined above), and records the port number of the + -- first target. Therefore it (should) only return priority + -- 0 records, and the input data is constructed such that the + -- last two digits of the port number represent the percentage + -- of times that record should (on average) be picked first. + + -- To prevent random test failures, we test across a handful + -- of fixed (randomly selected) seeds. + for _, seed in ipairs({ 8401877, 3943829, 7830992 }) do + math.randomseed(seed); + + local results = {}; + local function run() + local run_results = {}; + local r = resolver.new("example.com", "xmpp-server"); + local function record_target(...) + if ... == nil then + -- No more targets + return; + end + run_results = { ... }; + end + r:next(record_target); + return run_results[3]; + end + + for _ = 1, 1000 do + local port = run(); + results[port] = (results[port] or 0) + 1; + end + + local ports = {}; + for port in pairs(results) do + table.insert(ports, port); + end + table.sort(ports); + for _, port in ipairs(ports) do + --print("PORT", port, tostring((results[port]/1000) * 100).."% hits (expected "..tostring(port-5200).."%)"); + local hit_pct = (results[port]/1000) * 100; + local expected_pct = port - 5200; + --print(hit_pct, expected_pct, math.abs(hit_pct - expected_pct)); + assert.is_true(math.abs(hit_pct - expected_pct) < 5); + end + --print("---"); + end + end); +end); |