mod_posix: Move everything to util.startup
This allows greater control over the order of events.
Notably, the internal ordering between daemonization, initialization of
libunbound and setup of signal handling is sensitive.
libunbound starts a separate thread for processing DNS requests.
If this thread is started before signal handling has been set up, it
will not inherit the signal handlers and instead behave as it would have
before signal handlers were set up, i.e. cause the whole process to
immediately exit.
libunbound is usually initialized on the first DNS request, usually
triggered by an outgoing s2s connection attempt.
If daemonization happens before signals have been set up, signals may
not be processed at all.
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);