From: Peter Lemenkov <lemenkov@gmail.com>

Date: Thu, 19 May 2016 16:04:56 +0300

Subject: [PATCH] Remove excessive sd_notify code

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>

diff --git a/src/rabbit.erl b/src/rabbit.erl

index 2b043178a..81ddc4e45 100644

--- a/src/rabbit.erl

+++ b/src/rabbit.erl

@@ -349,123 +349,9 @@ broker_start() ->

     Plugins = rabbit_plugins:setup(),

     ToBeLoaded = Plugins ++ ?APPS,

     start_apps(ToBeLoaded),

-    maybe_sd_notify(),

     ok = rabbit_lager:broker_is_started(),

     ok = log_broker_started(rabbit_plugins:strictly_plugins(rabbit_plugins:active())).

-%% Try to send systemd ready notification if it makes sense in the

-%% current environment. standard_error is used intentionally in all

-%% logging statements, so all this messages will end in systemd

-%% journal.

-maybe_sd_notify() ->

-    case sd_notify_ready() of

-        false ->

-            io:format(standard_error, "systemd READY notification failed, beware of timeouts~n", []);

-        _ ->

-            ok

-    end.

-

-sd_notify_ready() ->

-    case {os:type(), os:getenv("NOTIFY_SOCKET")} of

-        {{win32, _}, _} ->

-            true;

-        {_, [_|_]} -> %% Non-empty NOTIFY_SOCKET, give it a try

-            sd_notify_legacy() orelse sd_notify_socat();

-        _ ->

-            true

-    end.

-

-sd_notify_data() ->

-    "READY=1\nSTATUS=Initialized\nMAINPID=" ++ os:getpid() ++ "\n".

-

-sd_notify_legacy() ->

-    case code:load_file(sd_notify) of

-        {module, sd_notify} ->

-            SDNotify = sd_notify,

-            SDNotify:sd_notify(0, sd_notify_data()),

-            true;

-        {error, _} ->

-            false

-    end.

-

-%% socat(1) is the most portable way the sd_notify could be

-%% implemented in erlang, without introducing some NIF. Currently the

-%% following issues prevent us from implementing it in a more

-%% reasonable way:

-%% - systemd-notify(1) is unstable for non-root users

-%% - erlang doesn't support unix domain sockets.

-%%

-%% Some details on how we ended with such a solution:

-%%   https://github.com/rabbitmq/rabbitmq-server/issues/664

-sd_notify_socat() ->

-    case sd_current_unit() of

-        {ok, Unit} ->

-            io:format(standard_error, "systemd unit for activation check: \"~s\"~n", [Unit]),

-            sd_notify_socat(Unit);

-        _ ->

-            false

-    end.

-

-socat_socket_arg("@" ++ AbstractUnixSocket) ->

-    "abstract-sendto:" ++ AbstractUnixSocket;

-socat_socket_arg(UnixSocket) ->

-    "unix-sendto:" ++ UnixSocket.

-

-sd_open_port() ->

-    open_port(

-      {spawn_executable, os:find_executable("socat")},

-      [{args, [socat_socket_arg(os:getenv("NOTIFY_SOCKET")), "STDIO"]},

-       use_stdio, out]).

-

-sd_notify_socat(Unit) ->

-    try sd_open_port() of

-        Port ->

-            Port ! {self(), {command, sd_notify_data()}},

-            Result = sd_wait_activation(Port, Unit),

-            port_close(Port),

-            Result

-    catch

-        Class:Reason ->

-            io:format(standard_error, "Failed to start socat ~p:~p~n", [Class, Reason]),

-            false

-    end.

-

-sd_current_unit() ->

-    CmdOut = os:cmd("ps -o unit= -p " ++ os:getpid()),

-    case catch re:run(CmdOut, "([-.@0-9a-zA-Z]+)", [unicode, {capture, all_but_first, list}]) of

-        {'EXIT', _} ->

-            error;

-        {match, [Unit]} ->

-            {ok, Unit};

-        _ ->

-            error

-    end.

-

-sd_wait_activation(Port, Unit) ->

-    case os:find_executable("systemctl") of

-        false ->

-            io:format(standard_error, "'systemctl' unavailable, falling back to sleep~n", []),

-            timer:sleep(5000),

-            true;

-        _ ->

-            sd_wait_activation(Port, Unit, 10)

-    end.

-

-sd_wait_activation(_, _, 0) ->

-    io:format(standard_error, "Service still in 'activating' state, bailing out~n", []),

-    false;

-sd_wait_activation(Port, Unit, AttemptsLeft) ->

-    case os:cmd("systemctl show --property=ActiveState -- '" ++ Unit ++ "'") of

-        "ActiveState=activating\n" ->

-            timer:sleep(1000),

-            sd_wait_activation(Port, Unit, AttemptsLeft - 1);

-        "ActiveState=" ++ _ ->

-            true;

-        _ = Err->

-            io:format(standard_error, "Unexpected status from systemd ~p~n", [Err]),

-            false

-    end.

-

 start_it(StartFun) ->

     Marker = spawn_link(fun() -> receive stop -> ok end end),

     case catch register(rabbit_boot, Marker) of