Use external configuration for the log to monitor

TODO.md

@@ -1,7 +1,6 @@
 TODO
 =====
 
-  - Allow to enable / disabled logfiles.
+  - gatherer.erl:29 Error on ++.
   - Limit number of emails that can be sent in a period of time.
-  - Store the logfiles in a configuration file.
   - gen_fsm for gatherer?

apps/log_monitor/src/config.erl

@@ -3,8 +3,8 @@
 
 -include_lib("mnesia_tables.hrl").
 
--export([create_group/2, monitor_log/3, unmonitor_log/1]).
+-export([status/0]).
--export([logfiles/0]).
+-export([reload/0]).
 -export([start_link/0, init/1, terminate/2]).
 -export([handle_info/2, handle_cast/2, handle_call/3]).
 -export([code_change/3]).
@@ -17,6 +17,7 @@ start_link() ->
 init([]) ->
     register(config, self()),
     Statuses = ets:new(log_statuses, []),
+    %% TODO: reload?
     mnesia:activity(
       transaction,
       fun() ->
@@ -49,50 +50,22 @@ handle_info(_Msg, State) ->
 handle_cast(_Msg, State) ->
     {noreply, State}.
 
-handle_call({create_group, Name, EmailReceivers}, _From, State) ->
+handle_call({reload}, _From, State = #state{statuses = Statuses}) ->
-    mnesia:activity(
+    {ok, File} = application:get_env(log_monitor, logfiles_config),
-      transaction,
+    {ok, Terms} = file:consult(File),
-      fun() ->
+    MonitoredLogs = proplists:get_value(monitored_logs, Terms),
-              case mnesia:read(log_monitor_group, Name) of
+    Groups = [#log_monitor_group{name = Name, email_receivers = EmailReceivers} || {{group, Name}, {email_receivers, EmailReceivers}, _} <- MonitoredLogs],
-                  [] ->
+    Logfiles = utils:flatten([[#log_monitor_file{file = F, error_regex = ErrorRegex, group = Name} || {{file, F}, {error_regex, ErrorRegex}} <- Logfiles]
-                      mnesia:write(#log_monitor_group{name = Name, email_receivers = EmailReceivers}),
+                || {{group, Name}, {email_receivers, _}, {logfiles, Logfiles}} <- MonitoredLogs]),
+    GroupsPartitions = compare_groups(Groups),
+    manage_deleted_groups(proplists:get_value(deleted, GroupsPartitions)),
+    manage_existing_groups(proplists:get_value(existing, GroupsPartitions)),
+    manage_new_groups(proplists:get_value(new, GroupsPartitions)),
+    LogfilesPartitions = compare_logfiles(Logfiles),
+    manage_deleted_logfiles(proplists:get_value(deleted, LogfilesPartitions), Statuses),
+    manage_existing_logfiles(proplists:get_value(existing, LogfilesPartitions)),
+    manage_new_logfiles(proplists:get_value(new, LogfilesPartitions), Statuses),
     {reply, ok, State};
-                  _ -> {reply, {error, "Duplicate"}, State}
-              end
-      end);
-handle_call({monitor, Group, File, ErrorRegex}, _From, State) ->
-    mnesia:activity(
-      transaction,
-      fun() ->
-              case mnesia:read(log_monitor_group, Group) of
-                  [{log_monitor_group, Group, _}] ->
-                      case mnesia:read(log_monitor_file, File) of
-                          [] ->
-                              mnesia:write(#log_monitor_file{
-                                              file = File,
-                                              error_regex = ErrorRegex,
-                                              group = Group,
-                                              status = enabled}),
-                              logfiles_sup:add_child([File, ErrorRegex]),
-                              {reply, ok, State};
-                          _ -> {reply, {error, "Duplicate"}, State}
-                      end;
-                  [] -> {reply, {error, "Unknown group"}, State}
-              end
-      end);
-handle_call({unmonitor, File}, _From, State = #state{statuses = Statuses}) ->
-    mnesia:activity(
-      transaction,
-      fun() ->
-              case mnesia:read(log_monitor_file, File) of
-                  [{log_monitor_file, File, _, _, _}] ->
-                      mnesia:delete({log_monitor_file, File}),
-                      ets:delete(Statuses, File),
-                      logfiles_sup:remove_child(File),
-                      {reply, ok, State};
-                  _ -> {reply, {error, "File not found"}, State}
-              end
-      end);
 handle_call({get_statuses}, _From, State = #state{statuses = Statuses}) ->
     {reply, ets:tab2list(Statuses), State}.
 
@@ -102,14 +75,115 @@ terminate(_Reason, _State) ->
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
 
-create_group(Name, EmailReceivers) ->
+status() ->
-    gen_server:call(config, {create_group, Name, EmailReceivers}).
-
-monitor_log(Group, File, ErrorRegex) ->
-    gen_server:call(config, {monitor, Group, File, ErrorRegex}).
-
-unmonitor_log(File) ->
-    gen_server:call(config, {unmonitor, File}).
-
-logfiles() ->
     gen_server:call(config, {get_statuses}).
+
+reload() ->
+    gen_server:call(config, {reload}).
+
+compare_groups(Groups) ->
+    Old = list_groups(),
+    Deleted = lists:filter(fun(Name) -> not lists:any(fun(#log_monitor_group{name = N, email_receivers = _}) -> N == Name end, Groups) end, Old),
+    Existing = lists:filter(fun(#log_monitor_group{name = Name, email_receivers = _}) -> lists:member(Name, Old) end, Groups),
+    New = lists:filter(fun(#log_monitor_group{name = Name, email_receivers = _}) -> not lists:member(Name, Old) end, Groups),
+    [
+     {deleted, Deleted},
+     {existing, Existing},
+     {new, New}
+    ].
+
+manage_deleted_groups(Groups) ->
+    mnesia:activity(
+      transaction,
+      fun() ->
+              lists:foldl(fun(Name, _Acc) ->
+                                  mnesia:delete({log_monitor_group, Name})
+                          end, [], Groups)
+      end).
+
+manage_existing_groups(Groups) ->
+    mnesia:activity(
+      transaction,
+      fun() ->
+              lists:foldl(fun(Group, _Acc) ->
+                                  mnesia:write(Group)
+                          end, [], Groups)
+      end).
+
+manage_new_groups(Groups) ->
+    mnesia:activity(
+      transaction,
+      fun() ->
+              lists:foldl(fun(Group, _Acc) ->
+                                  mnesia:write(Group)
+                          end, [], Groups)
+      end).
+
+list_groups() ->
+    mnesia:activity(
+      transaction,
+      fun() ->
+              mnesia:foldl(
+                fun(#log_monitor_group{name = Name, email_receivers = _}, Acc) ->
+                        [Name | Acc]
+                end, [], log_monitor_group)
+      end).
+
+compare_logfiles(Logfiles) ->
+    Old= list_logfiles(),
+    Deleted = lists:filter(fun(File) -> not lists:any(fun(#log_monitor_file{file = F, error_regex = _, group = _}) -> F == File end, Logfiles) end, Old),
+    Existing = lists:filter(fun(#log_monitor_file{file = File, error_regex = _, group = _}) -> lists:member(File, Old) end, Logfiles),
+    New = lists:filter(fun(#log_monitor_file{file = File, error_regex = _, group = _}) -> not lists:member(File, Old) end, Logfiles),
+    [
+     {deleted, Deleted},
+     {existing, Existing},
+     {new, New}
+    ].
+
+manage_deleted_logfiles(Logfiles, Statuses) ->
+    mnesia:activity(
+      transaction,
+      fun() ->
+              lists:foldl(fun(File, _Acc) ->
+                                  logfiles_sup:remove_child(File),
+                                  mnesia:delete({log_monitor_file, File}),
+                                  ets:delete(Statuses, File)
+                          end, [], Logfiles)
+      end).
+
+manage_existing_logfiles(Logfiles) ->
+    mnesia:activity(
+      transaction,
+      fun() ->
+              lists:foldl(fun(Logfile = #log_monitor_file{file = File, error_regex = ErrorRegex, group = _}, _Acc) ->
+                                  mnesia:write(Logfile),
+                                  case mnesia:read(log_monitor_file, File) of
+                                      [#log_monitor_file{file = File, error_regex = ErrorRegex, group = _}] -> ok;
+                                      _ ->
+                                          %% The error regex has changed
+                                          logfiles_sup:remove_child(File),
+                                          logfiles_sup:add_child([File, ErrorRegex])
+                                  end
+                          end, [], Logfiles)
+      end).
+
+manage_new_logfiles(Logfiles, Statuses) ->
+    mnesia:activity(
+      transaction,
+      fun() ->
+              lists:foldl(fun(Logfile = #log_monitor_file{file = File, error_regex = ErrorRegex, group = _}, _Acc) ->
+                                  mnesia:write(Logfile),
+                                  ets:insert(Statuses, {File, inactive}),
+                                  logfiles_sup:add_child([File, ErrorRegex])
+                          end, [], Logfiles)
+      end).
+
+list_logfiles() ->
+    mnesia:activity(
+      transaction,
+      fun() ->
+              mnesia:foldl(
+                fun(#log_monitor_file{file = File, error_regex = _, group = _}, Acc) ->
+                        [File | Acc]
+                end, [], log_monitor_file)
+      end).

apps/log_monitor/src/log_monitor.app.src

@@ -7,7 +7,9 @@
    [kernel,
     stdlib,
     gen_smtp,
-    mnesia
+    mnesia,
+    %% Observer
+    observer, wx, runtime_tools
    ]},
   {env,[]},
   {modules, []},

apps/log_monitor/src/mailer.erl

@@ -90,7 +90,7 @@ send_email(File, Text) ->
               Connection
              )
     catch
-        _Throw ->
+        error:_ ->
             ok
     end.
 
@@ -107,10 +107,11 @@ receivers(File) ->
       transaction,
       fun() ->
               case mnesia:read(log_monitor_file, File) of
-                  [{log_monitor_file, File, _, _, Group}] ->
+                  [{log_monitor_file, File, _, Group}] ->
                       case mnesia:read(log_monitor_group, Group) of
                           [{log_monitor_group, Group, EmailReceivers}] ->
-                              EmailReceivers
+                              EmailReceivers;
+                          _ -> throw(file_group_not_found)
                       end;
                   _ -> throw(file_not_found)
               end

apps/log_monitor/src/mnesia_tables.hrl

@@ -3,7 +3,7 @@
 
 %% Mnesia tables
 -record(log_monitor_group, {name, email_receivers=[]}).
--record(log_monitor_file, {file, error_regex, status, group}).
+-record(log_monitor_file, {file, error_regex, group}).
 -record(log_monitor_error, {id, file, text}).
 
 -endif.

apps/log_monitor/src/utils.erl

@@ -0,0 +1,10 @@
+-module(utils).
+
+-export([flatten/1]).
+
+flatten(X) -> flatten(X,[]).
+
+flatten([],Acc)  -> Acc;
+flatten([[]|T],Acc)  -> flatten(T, Acc);
+flatten([[_|_]=H|T],Acc) -> flatten(T, flatten(H,Acc));
+flatten([H|T],Acc) -> flatten(T,Acc++[H]) .

config/log_monitor.config

@@ -16,7 +16,8 @@
             {password, ""}]
           }
         ]
-      }
+      },
+      {logfiles_config, "/home/fsalvini/gitRepos/log_monitor/config/logfiles.config"}
     ]
   },
   %% Directory where the application data is stored.

config/logfiles.config

@@ -0,0 +1,12 @@
+{monitored_logs, [
+    {
+        {group, "Test"},
+        {email_receivers, ["user@example.com"]},
+        {logfiles, [
+            {
+                {file, "/tmp/lines.log"},
+                {error_regex, "ERROR"}
+            }
+        ]}
+    }
+]}.

config/rebar.lock

@@ -0,0 +1 @@
+[].