Disable l4lb mesos poller on new dc/os clusters

AVENTER-UG · andreaspeters · Feb 11, 2021 · Aug 12, 2019 · Aug 13, 2019 · Aug 15, 2019
commit eb0552fbd4455db0b22093a13cf956b341fbb788
diff --git a/apps/dcos_l4lb/src/dcos_l4lb_mesos_poller.erl b/apps/dcos_l4lb/src/dcos_l4lb_mesos_poller.erl
@@ -5,6 +5,7 @@
 
 -include("dcos_l4lb.hrl").
 -include_lib("kernel/include/logger.hrl").
+-include_lib("stdlib/include/ms_transform.hrl").
 
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").
@@ -25,7 +26,8 @@
 
 -record(state, {
     backoff :: backoff:backoff(),
-    timer_ref = make_ref() :: reference()
+    timer_ref = make_ref() :: reference(),
+    wait_ref :: reference() | undefined
 }).
 
 -type task() :: dcos_net_mesos_listener:task().
@@ -56,7 +58,7 @@ init([]) ->
     PollMaxInterval = dcos_l4lb_config:agent_poll_max_interval(),
     Backoff0 = backoff:init(PollInterval, PollMaxInterval, self(), poll),
     Backoff = backoff:type(Backoff0, jitter),
-    {ok, #state{backoff = Backoff}, {continue, poll}}.
+    {ok, #state{backoff = Backoff}, {continue, wait}}.
 
 handle_call(Request, _From, State) ->
     ?LOG_WARNING("Unexpected request: ~p", [Request]),
@@ -66,12 +68,27 @@ handle_cast(Request, State) ->
     ?LOG_WARNING("Unexpected request: ~p", [Request]),
     {noreply, State}.
 
+handle_info({lashup_kv_event, WRef, ?VIPS_KEY2}, State) ->
+    ok = lashup_kv:flush(WRef, ?VIPS_KEY2),
+    case lashup_kv:raw_value(?VIPS_KEY2) of
+        false ->
+            % ?VIPS_KEY2 doesn't exist
+            {noreply, State};
+        _Value ->
+            ok = lashup_kv:unsubscribe(WRef),
+            {noreply, State#state{wait_ref = undefined}, {continue, poll}}
+    end;
 handle_info({timeout, TRef, poll}, #state{timer_ref = TRef} = State) ->
     {noreply, State, {continue, poll}};
 handle_info(Info, State) ->
     ?LOG_WARNING("Unexpected info: ~p", [Info]),
     {noreply, State}.
 
+handle_continue(wait, State) ->
+    % Wait for ?VIPS_KEY2 and start polling only if it exists.
+    MatchSpec = ets:fun2ms(fun ({?VIPS_KEY2}) -> true end),
+    {ok, WRef} = lashup_kv:subscribe(MatchSpec),
+    {noreply, State#state{wait_ref=WRef}};
 handle_continue(poll, #state{backoff = Backoff0} = State) ->
     {Backoff, TimerRef} = handle_poll(Backoff0),
     {noreply, State#state{backoff = Backoff, timer_ref = TimerRef}, hibernate};

diff --git a/apps/dcos_l4lb/test/dcos_l4lb_mesos_poller_SUITE.erl b/apps/dcos_l4lb/test/dcos_l4lb_mesos_poller_SUITE.erl
@@ -57,6 +57,7 @@ node_ip() ->
 
 ensure_l4lb_started() ->
     {ok, _} = application:ensure_all_started(dcos_l4lb),
+    {ok, _} = lashup_kv:request_op(?VIPS_KEY2, {update, []}),
     meck:wait(dcos_net_mesos_listener, poll, '_', 5000),
     meck:wait(dcos_l4lb_mgr, local_port_mappings, '_', 100),
     timer:sleep(100).