Module to detect postgres master/slave (tid14728)

git-svn-id: https://labs.omniti.com/resmon/trunk@433 8c0face9-b7db-6ec6-c4b3-d5f7145c7d55

lib/Core/PostgresMaster.pm

+package Core::PostgresMaster;
+
+use strict;
+use warnings;
+
+use base 'Resmon::Module';
+
+use Resmon::ExtComm qw(run_command cache_command);
+
+=pod
+
+=head1 NAME
+
+Core::PostgresMaster - a sample/template resmon module
+
+=head1 SYNOPSIS
+
+ Core::PostgresMaster {
+     postgres_state: pgdata => /data/postgres/pgdata
+ }
+
+=head1 DESCRIPTION
+
+This module detects whether a postgres database is master or slave by looking
+for the presence or absence of a recovery.conf file in the pgdata directory.
+
+=head1 CONFIGURATION
+
+=over
+
+=item check_name
+
+The check name is descriptive only in this check. It is not used for anything.
+Some checks use the check_name as part of the configuration, such as
+free space checks that specify the filesystem to use.
+
+=item pgdata
+
+The path to the pgdata directory.
+
+=back
+
+=head1 METRICS
+
+=over
+
+=item state
+
+The state of the database as a string - master or slave.
+
+=back
+
+=cut
+
+sub handler {
+    my $self = shift;
+    unless (exists($self->{config}->{pgdata})) {
+        return {
+            "error" => ["Pgdata path is undefined", "s"]
+        }
+    };
+    my $state;
+    if (-e "$self->{config}->{pgdata}/recovery.conf") {
+        $state = "slave";
+    } else {
+        $state = "master";
+    };
+    return {
+        "state" => [$state, "s"],
+    };
+};
+
+1;