Fixes a bug with thumbnail generation.

src/erli_thumbnails.erl

@@ -30,6 +30,7 @@ start() ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
 
 generate_thumbnails() ->
+    error_logger:info_msg("[INFO] Initiating thumbnail collection"),
     gen_server:cast(?SERVER, gen_thumbs).
 
 %%-----------------------------------------------------------
@@ -72,10 +73,10 @@ grab([T|Targets], {Exe, ThumbnailDir} = Ctx) ->
     ThumbnailPath = filename:join([ThumbnailDir,
 				   <<(T#target.id)/bitstring, ".jpeg">>]),
     Cmd = <<Exe/bitstring, " ",  TUrl/bitstring, " ", ThumbnailPath/bitstring>>,
-    case os:cmd(binary_to_list(Cmd)) of
-	0 ->
+    case erli_utils:run(binary_to_list(Cmd)) of
+	{0, _} ->
 	    erli_storage:thumbnail_generated(T);
-	_ ->
+	{_, _ErrorDesc} ->
 	    error_logger:info_msg(
 	      "[ERROR] Generation of a thumbnail for ~s failed~n", [TUrl])
     end,

src/erli_utils.erl

@@ -20,7 +20,8 @@
 	 generate_etag/1,
 	 unix_timestamp/0,
 	 parse_range_header/2,
-	 build_content_range_header/2]).
+	 build_content_range_header/2,
+	 run/1]).
 
 -include("models.hrl").
 -include_lib("webmachine/include/webmachine.hrl").
@@ -32,6 +33,7 @@
 -type file_path() :: string().
 -type maybe_int() :: [] | integer().
 -type etag() :: string().
+-type exit_status() :: non_neg_integer().
 
 %%-----------------------------------------------------------
 %% API Methods
@@ -189,10 +191,30 @@ get_location(Ip) ->
     {ok, Rec} = egeoip:lookup(Ip),
     list_to_binary(egeoip:get(Rec, country_code)).
 
+-spec run(string()) -> {exit_status(), iolist()}.
+run(Cmd) ->
+    Opt = [stream, exit_status, use_stdio, stderr_to_stdout, in, eof],
+    P = open_port({spawn, Cmd}, Opt),
+    get_data(P, []).
+
+
 %%-----------------------------------------------------------
 %% Internal Methods
 %%-----------------------------------------------------------
 
+-spec get_data(port(), iolist()) -> {exit_status(), iolist()}.
+get_data(P, D) ->
+    receive
+	{P, {data, D1}} ->
+	    get_data(P, [D|D1]);
+	{P, eof} ->
+	    port_close(P),
+	    receive
+		{P, {exit_status, N}} ->
+		    {N, lists:reverse(D)}
+	    end
+    end.
+
 -spec parse_range(string(), collection_type()) ->
 			 range() |
 			 {error, invalid_range}.