Unify the more resilient hostname check, refactor out this code into a new module.

4 files changed, 82 insertions, 50 deletions

diff --git a/src/rabbit.erl b/src/rabbit.erl
index 293864ea..5ada38d2 100644
--- a/src/rabbit.erl
+++ b/src/rabbit.erl
@@ -22,7 +22,7 @@
          status/0, is_running/0, is_running/1, environment/0,
          rotate_logs/1, force_event_refresh/0]).
 
--export([start/2, stop/1, diagnostics/1]).
+-export([start/2, stop/1]).
 
 -export([log_location/1]). %% for testing
 
@@ -236,7 +236,6 @@
 			{'required',[any(),...]}}} |
 		      {'ok',pid()}).
 -spec(stop/1 :: (_) -> 'ok').
--spec(diagnostics/1 :: ([node()]) -> string()).
 
 -endif.
 
@@ -510,7 +509,7 @@ boot_step_error({error, {timeout_waiting_for_tables, _}}, _Stacktrace) ->
             Ns -> {format("Timeout contacting cluster nodes: ~p.~n",
                           [Ns]), Ns}
         end,
-    boot_error(Err ++ diagnostics(Nodes) ++ "~n~n", []);
+    boot_error(Err ++ rabbit_nodes:diagnostics(Nodes) ++ "~n~n", []);
 
 boot_step_error(Reason, Stacktrace) ->
     boot_error("Error description:~n   ~p~n~n"
@@ -524,37 +523,6 @@ boot_error(Format, Args) ->
     timer:sleep(1000),
     exit({?MODULE, failure_during_boot}).
 
-
-diagnostics(Nodes) ->
-    Hosts = lists:usort([element(2, rabbit_misc:nodeparts(Node)) ||
-                            Node <- Nodes]),
-    NodeDiags = [{"~nDIAGNOSTICS~n===========~n~n"
-                  "nodes to contact: ~p~n~n"
-                  "hosts, their running nodes and ports:", [Nodes]}] ++
-        [diagnostics_host(Host) || Host <- Hosts] ++
-        diagnostics0(),
-    lists:flatten([io_lib:format(F ++ "~n", A) || NodeDiag <- NodeDiags,
-                                                  {F, A}   <- [NodeDiag]]).
-
-diagnostics0() ->
-    [{"~ncurrent node details:~n- node name: ~w", [node()]},
-     case init:get_argument(home) of
-         {ok, [[Home]]} -> {"- home dir: ~s", [Home]};
-         Other          -> {"- no home dir: ~p", [Other]}
-     end,
-     {"- cookie hash: ~s", [rabbit_misc:cookie_hash()]}].
-
-diagnostics_host(Host) ->
-    case net_adm:names(Host) of
-        {error, EpmdReason} ->
-            {"- unable to connect to epmd on ~s: ~w",
-             [Host, EpmdReason]};
-        {ok, NamePorts} ->
-            {"- ~s: ~p",
-             [Host, [{list_to_atom(Name), Port} ||
-                        {Name, Port} <- NamePorts]]}
-    end.
-
 format(F, A) -> lists:flatten(io_lib:format(F, A)).
 
 %%---------------------------------------------------------------------------
diff --git a/src/rabbit_control.erl b/src/rabbit_control.erl
index b31661b3..48d319c8 100644
--- a/src/rabbit_control.erl
+++ b/src/rabbit_control.erl
@@ -142,7 +142,7 @@ print_report0(Node, {Module, InfoFun, KeysFun}, VHostArg) ->
 print_error(Format, Args) -> fmt_stderr("Error: " ++ Format, Args).
 
 print_badrpc_diagnostics(Node) ->
-    fmt_stderr(rabbit:diagnostics([Node]), []).
+    fmt_stderr(rabbit_nodes:diagnostics([Node]), []).
 
 stop() ->
     ok.
diff --git a/src/rabbit_nodes.erl b/src/rabbit_nodes.erl
new file mode 100644
index 00000000..6cfa5fa9
--- /dev/null
+++ b/src/rabbit_nodes.erl
@@ -0,0 +1,77 @@
+%% The contents of this file are subject to the Mozilla Public License
+%% Version 1.1 (the "License"); you may not use this file except in
+%% compliance with the License. You may obtain a copy of the License
+%% at http://www.mozilla.org/MPL/
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and
+%% limitations under the License.
+%%
+%% The Original Code is RabbitMQ.
+%%
+%% The Initial Developer of the Original Code is VMware, Inc.
+%% Copyright (c) 2007-2011 VMware, Inc.  All rights reserved.
+%%
+
+-module(rabbit_nodes).
+
+-export([names/1, diagnostics/1]).
+
+-define(EPMD_TIMEOUT, 30000).
+
+%%----------------------------------------------------------------------------
+%% Specs
+%%----------------------------------------------------------------------------
+
+-ifdef(use_specs).
+
+-spec(names/1 :: (string()) -> rabbit_types:ok_or_error2(
+                                 [{string(), integer()}], term())).
+-spec(diagnostics/1 :: ([node()]) -> string()).
+
+-endif.
+
+%%----------------------------------------------------------------------------
+
+names(Hostname) ->
+    Self = self(),
+    process_flag(trap_exit, true),
+    Pid = spawn_link(fun () -> Self ! {names, net_adm:names(Hostname)} end),
+    timer:exit_after(?EPMD_TIMEOUT, Pid, timeout),
+    Res = receive
+              {names, Names}        -> Names;
+              {'EXIT', Pid, Reason} -> {error, Reason}
+          end,
+    process_flag(trap_exit, false),
+    Res.
+
+diagnostics(Nodes) ->
+    Hosts = lists:usort([element(2, rabbit_misc:nodeparts(Node)) ||
+                            Node <- Nodes]),
+    NodeDiags = [{"~nDIAGNOSTICS~n===========~n~n"
+                  "nodes to contact: ~p~n~n"
+                  "hosts, their running nodes and ports:", [Nodes]}] ++
+        [diagnostics_host(Host) || Host <- Hosts] ++
+        diagnostics0(),
+    lists:flatten([io_lib:format(F ++ "~n", A) || NodeDiag <- NodeDiags,
+                                                  {F, A}   <- [NodeDiag]]).
+
+diagnostics0() ->
+    [{"~ncurrent node details:~n- node name: ~w", [node()]},
+     case init:get_argument(home) of
+         {ok, [[Home]]} -> {"- home dir: ~s", [Home]};
+         Other          -> {"- no home dir: ~p", [Other]}
+     end,
+     {"- cookie hash: ~s", [rabbit_misc:cookie_hash()]}].
+
+diagnostics_host(Host) ->
+    case names(Host) of
+        {error, EpmdReason} ->
+            {"- unable to connect to epmd on ~s: ~w",
+             [Host, EpmdReason]};
+        {ok, NamePorts} ->
+            {"- ~s: ~p",
+             [Host, [{list_to_atom(Name), Port} ||
+                        {Name, Port} <- NamePorts]]}
+    end.
diff --git a/src/rabbit_prelaunch.erl b/src/rabbit_prelaunch.erl
index 5fc67662..2dc1b156 100644
--- a/src/rabbit_prelaunch.erl
+++ b/src/rabbit_prelaunch.erl
@@ -22,7 +22,6 @@
 
 -define(BaseApps, [rabbit]).
 -define(ERROR_CODE, 1).
--define(EPMD_TIMEOUT, 30000).
 
 %%----------------------------------------------------------------------------
 %% Specs
@@ -246,13 +245,13 @@ duplicate_node_check([]) ->
 duplicate_node_check(NodeStr) ->
     Node = rabbit_misc:makenode(NodeStr),
     {NodeName, NodeHost} = rabbit_misc:nodeparts(Node),
-    case names(NodeHost) of
+    case rabbit_nodes:names(NodeHost) of
         {ok, NamePorts}  ->
             case proplists:is_defined(NodeName, NamePorts) of
                 true -> io:format("node with name ~p "
                                   "already running on ~p~n",
                                   [NodeName, NodeHost]),
-                        io:format(rabbit:diagnostics([Node]) ++ "~n"),
+                        io:format(rabbit_nodes:diagnostics([Node]) ++ "~n"),
                         terminate(?ERROR_CODE);
                 false -> ok
             end;
@@ -278,15 +277,3 @@ terminate(Status) ->
                       after infinity -> ok
                       end
     end.
-
-names(Hostname) ->
-    Self = self(),
-    process_flag(trap_exit, true),
-    Pid = spawn_link(fun () -> Self ! {names, net_adm:names(Hostname)} end),
-    timer:exit_after(?EPMD_TIMEOUT, Pid, timeout),
-    Res = receive
-              {names, Names}        -> Names;
-              {'EXIT', Pid, Reason} -> {error, Reason}
-          end,
-    process_flag(trap_exit, false),
-    Res.