Make already_started error explicit in start_vhost. Export start_vhost/2

Already started status can be used by CLI tools and should
be returned from `start_vhost` function.
`start_vhost/2` is used in the management API

1 files changed, 22 insertions, 17 deletions

diff --git a/src/rabbit_vhost_sup_sup.erl b/src/rabbit_vhost_sup_sup.erl
index 93c26d4e0f..19d7cf61b7 100644
--- a/src/rabbit_vhost_sup_sup.erl
+++ b/src/rabbit_vhost_sup_sup.erl
@@ -23,15 +23,16 @@
 -export([init/1]).
 
 -export([start_link/0, start/0]).
--export([init_vhost/1, get_vhost_sup/1, get_vhost_sup/2, save_vhost_sup/3]).
--export([delete_on_all_nodes/1]).
--export([start_on_all_nodes/1]).
-
--export([save_vhost_process/2]).
+-export([init_vhost/1,
+         start_vhost/1, start_vhost/2,
+         get_vhost_sup/1, get_vhost_sup/2,
+         save_vhost_sup/3,
+         save_vhost_process/2]).
+-export([delete_on_all_nodes/1, start_on_all_nodes/1]).
 -export([is_vhost_alive/1]).
 
 %% Internal
--export([stop_and_delete_vhost/1, start_vhost/1]).
+-export([stop_and_delete_vhost/1]).
 
 -record(vhost_sup, {vhost, vhost_sup_pid, wrapper_pid, vhost_process_pid}).
 
@@ -61,7 +62,12 @@ init([]) ->
 start_on_all_nodes(VHost) ->
     NodesStart = [ {Node, start_vhost(VHost, Node)}
                    || Node <- rabbit_nodes:all_running() ],
-    Failures = lists:filter(fun({_, {ok, _}}) -> false; (_) -> true end, NodesStart),
+    Failures = lists:filter(fun
+                               ({_, {ok, _}}) -> false;
+                               ({_, {error, {already_started, _}}}) -> false;
+                               (_) -> true
+                            end,
+                            NodesStart),
     case Failures of
         []     -> ok;
         Errors -> {error, {failed_to_start_vhost_on_nodes, Errors}}
@@ -112,6 +118,11 @@ stop_and_delete_vhost(VHost, Node) ->
 init_vhost(VHost) ->
     case start_vhost(VHost) of
         {ok, _} -> ok;
+        {error, {already_started, _}} ->
+            rabbit_log:warning(
+                "Attempting to start an already started vhost '~s'.",
+                [VHost]),
+            ok;
         {error, {no_such_vhost, VHost}} ->
             {error, {no_such_vhost, VHost}};
         {error, Reason} ->
@@ -163,22 +174,16 @@ get_vhost_sup(VHost) ->
 -spec start_vhost(rabbit_types:vhost(), node()) -> {ok, pid()} | {error, term()}.
 start_vhost(VHost, Node) ->
     case rabbit_misc:rpc_call(Node, rabbit_vhost_sup_sup, start_vhost, [VHost]) of
-        {ok, Pid} when is_pid(Pid) ->
-            {ok, Pid};
-        {badrpc, RpcErr} ->
-            {error, RpcErr}
+        {ok, Pid}        -> {ok, Pid};
+        {error, Err}     -> {error, Err};
+        {badrpc, RpcErr} -> {error, RpcErr}
     end.
 
 -spec start_vhost(rabbit_types:vhost()) -> {ok, pid()} | {error, term()}.
 start_vhost(VHost) ->
     case rabbit_vhost:exists(VHost) of
         false -> {error, {no_such_vhost, VHost}};
-        true  ->
-            case supervisor2:start_child(?MODULE, [VHost]) of
-                {ok, Pid}                       -> {ok, Pid};
-                {error, {already_started, Pid}} -> {ok, Pid};
-                {error, Err}                    -> {error, Err}
-            end
+        true  -> supervisor2:start_child(?MODULE, [VHost])
     end.
 
 -spec is_vhost_alive(rabbit_types:vhost()) -> boolean().