Merge pull request #3560 from esl/mu-local-iq-response-without-mnesia

Don't use mnesia for IQ response tracking

The code I am touching here is a bit old and a bit hairy.
I honestly didn't read that one and it took sometime to understand why we use mnesia there to begin with.

So, TLDR:

    the code I am touching allows to route an IQ from the SERVER to the CLIENT (the opposite way they usually go).
    it is used in mod_ping.
    though, the last thing I want is to replicate data, that is used by mod_ping in a big cluster (because of how often it is written).
    in the real life, that iq_response would never do RPC calls (at least for mod_ping, because the process sending IQ and receiving IQ is a c2s process). We still need to test it though :(

Proposed changes include:

    This change removes replication for IQ response tracking (useful in the big clusters, that use mod_ping)
    We use IQ IDs to locate the metadata for the IQ instead

big_tests/default.spec

@@ -91,6 +91,7 @@
 {suites, "tests", mam_send_message_SUITE}.
 {suites, "tests", dynamic_domains_SUITE}.
 {suites, "tests", auth_methods_for_c2s_SUITE}.
+{suites, "tests", local_iq_SUITE}.
 
 {config, ["test.config"]}.
 {logdir, "ct_report"}.

big_tests/dynamic_domains.spec

@@ -135,6 +135,7 @@
 
 {suites, "tests", domain_removal_SUITE}.
 {suites, "tests", auth_methods_for_c2s_SUITE}.
+{suites, "tests", local_iq_SUITE}.
 
 {config, ["dynamic_domains.config", "test.config"]}.
 

big_tests/tests/local_iq_SUITE.erl

@@ -0,0 +1,102 @@
+-module(local_iq_SUITE).
+
+-include_lib("common_test/include/ct.hrl").
+-include_lib("eunit/include/eunit.hrl").
+-include_lib("exml/include/exml.hrl").
+
+-compile([export_all, nowarn_export_all]).
+-import(distributed_helper, [mim/0, mim2/0, require_rpc_nodes/1, rpc/4, subhost_pattern/1]).
+-import(domain_helper, [host_type/0, secondary_host_type/0]).
+
+suite() ->
+    require_rpc_nodes([mim, mim2]).
+
+all() ->
+    [{group, iq_group}].
+
+groups() ->
+    [{iq_group, [], cases()}].
+
+cases() ->
+    [process_iq_works_across_multiple_nodes,
+     process_iq_timeout].
+
+%%--------------------------------------------------------------------
+%% Init & teardown
+%%--------------------------------------------------------------------
+
+init_per_suite(Config) ->
+    distributed_helper:add_node_to_cluster(mim2(), Config),
+    mongoose_helper:inject_module(mim(), ?MODULE, reload),
+    mongoose_helper:inject_module(mim2(), ?MODULE, reload),
+    escalus:init_per_suite(Config).
+
+end_per_suite(Config) ->
+    escalus:end_per_suite(Config).
+
+init_per_group(iq_group, Config) ->
+    Config.
+
+end_per_group(iq_group, Config) ->
+    escalus_fresh:clean(),
+    Config.
+
+init_per_testcase(Testcase, Config) ->
+    escalus:init_per_testcase(Testcase, Config).
+
+end_per_testcase(Testcase, Config) ->
+    escalus:end_per_testcase(Testcase, Config).
+
+%%--------------------------------------------------------------------
+%% Tests
+%%--------------------------------------------------------------------
+
+process_iq_works_across_multiple_nodes(Config) ->
+    %% Alice connects to node1
+    F = fun(Alice) ->
+          route_iq(Alice, undefined),
+          Stanza = escalus:wait_for_stanza(Alice),
+          escalus:assert(is_iq_get, [], Stanza),
+          escalus_client:send(Alice, escalus_stanza:iq_result(Stanza)),
+          receive
+              {result, _CbFrom, _CbTo, _CbAcc, _CbIQ} -> ok
+          after 5000 -> ct:fail(timeout_waiting_for_result)
+          end
+        end,
+    escalus:fresh_story(Config, [{alice, 1}], F).
+
+process_iq_timeout(Config) ->
+    F = fun(Alice) ->
+          route_iq(Alice, 1),
+          Stanza = escalus:wait_for_stanza(Alice),
+          escalus:assert(is_iq_get, [], Stanza),
+          receive
+              {result, _CbFrom, _CbTo, _CbAcc, CbIQ} -> timeout = CbIQ
+          after 5000 -> ct:fail(timeout_waiting_for_result)
+          end
+        end,
+    escalus:fresh_story(Config, [{alice, 1}], F).
+
+%%--------------------------------------------------------------------
+%% Helpers
+%%--------------------------------------------------------------------
+
+route_iq(Alice, Timeout) ->
+    Jid = escalus_client:full_jid(Alice),
+    Server = escalus_client:server(Alice),
+    To = jid:from_binary(Jid),
+    From = jid:from_binary(Server),
+    Query = #xmlel{name = <<"query">>,
+                   attrs = [{<<"xmlns">>, <<"cooltestns">>}]},
+    Xml = #xmlel{name = <<"iq">>,
+                 attrs = [{<<"type">>, <<"get">>},
+                          {<<"from">>, Server}, {<<"to">>, Jid}],
+                 children = [Query]},
+    Acc = rpc(mim(), mongoose_acc, new,
+              [#{location => #{}, lserver => Server, element => Xml}]),
+    IQ = rpc(mim(), jlib, iq_query_info, [Xml]),
+    Self = self(),
+    Callback = fun(CbFrom, CbTo, CbAcc, CbIQ) ->
+                       Self ! {result, CbFrom, CbTo, CbAcc, CbIQ}, CbAcc end,
+    Args = [From, To, Acc, IQ, Callback, Timeout],
+    rpc(mim2(), ejabberd_local, route_iq, Args).