Support wildcard modules (fixes #7)

This is done using a wildcard_handler method in addition to the normal handler
method. The wildcard_handler method is called if * is in the config file as
the check name, and the handler module is called for normal checks. By
default, both methods will die with "Not implemented", meaning modules can
implement one or both of the methods, depending on whether they support normal
checks, wildcard checks, or some combination of both.

git-svn-id: https://labs.omniti.com/resmon/branches/resmon2@386 8c0face9-b7db-6ec6-c4b3-d5f7145c7d55

lib/Resmon/Module.pm

@@ -12,9 +12,11 @@ sub new {
 }
 
 sub handler {
-    return {
-        'error_message' => ["Monitor not implemented", "s"]
-    }
+    die "Monitor not implemented.\n";
+}
+
+sub wildcard_handler {
+    die "Monitor not implemented.\n";
 }
 
 sub cache_metrics {

resmon

@@ -90,40 +90,51 @@ $status->serve_http_on($config->{interface}, $config->{port},
 while(1) {
     while(my($module_name, $mod_configs) = each %{$config->{Module}}) {
         while(my($check_name, $monitor_obj) = each %$mod_configs) {
-            my $check_metric = {};
+            my $check_metrics = {};
             my $starttime = [gettimeofday];
             # Get old status if it hasn't expired
-            $check_metric = $monitor_obj->get_cached_metrics();
+            $check_metrics = $monitor_obj->get_cached_metrics();
             # Otherwise, run the check
-            if (!$check_metric) {
+            if (!$check_metrics) {
                 my $timeout = $monitor_obj->{'check_timeout'} ||
                     $config->{'timeout'};
                 alarm($timeout);
+                my $handler;
                 eval {
                     local $SIG{ALRM} = sub { die "alarm\n" };
-                    $check_metric = $monitor_obj->handler();
+                    if ($check_name eq "*") {
+                        $check_metrics = $monitor_obj->wildcard_handler;
+                    } else {
+                        $check_metrics = {
+                            $check_name => $monitor_obj->handler
+                        };
+                    }
                 };
                 alarm 0;
                 # Store the last metrics for use by fresh_status_msg later
-                $monitor_obj->cache_metrics($check_metric);
+                $monitor_obj->cache_metrics($check_metrics);
             };
             my $checkproblem = $@;
-            my $results = {
-                last_runtime_seconds => sprintf("%.6f",
-                    tv_interval($starttime)),
-                metric => $check_metric
-            };
             if($checkproblem) {
                 chomp $checkproblem;
-                $results->{metric} = { "error" => ["$checkproblem", "s"]};
                 if ($checkproblem eq "alarm") {
-                    $results->{metric} = { "error" => ["Check timeout", "s"]};
+                    $checkproblem = "Check timeout";
                 }
+                $check_metrics = {
+                    $check_name => {"error" => ["$checkproblem", "s"]}
+                };
                 Resmon::ExtComm::clean_up;
             }
-            $status->store($module_name,$monitor_obj->{'check_name'}, $results);
-            $status->write($module_name,$monitor_obj->{'check_name'},
-                $results->{'metric'}, $debug);
+            foreach my $name (keys %$check_metrics) {
+                my $results = {
+                    last_runtime_seconds => sprintf("%.6f",
+                        tv_interval($starttime)),
+                    metric => $check_metrics->{$name}
+                };
+                $status->store($module_name,$name, $results);
+                $status->write($module_name,$name, $results->{'metric'},
+                    $debug);
+            }
         }
     }
     $status->close();