Merge pull request #3 from bensinober/master

Improvements made by bensinober

README.md

@@ -5,10 +5,20 @@ Nagios plugin to check JSON attributes via http(s).
 
 This Plugin is a fork of the existing JSON Plugin from https://github.com/bbuchalter/check_json with the enhancements of using the Nagios::Plugin Perl Module, allowing to use thresholds and performance data collection from various json attributes.
 
-Usage: `check_json -U <URL> -a <attribute> [ -v|--verbose ] [-t <timeout>] [ -c|--critical <threshold> ] [ -w|--warning <threshold> ]`
+Performance data is also enhanced to extract performance data compliant to Nagios and Graphite standards. One attribute is selected for thresholds check, multiple others can be added for extracting performance data. This plugin is aimed at simplifying Nagios, Icinga & Icinga2 polling of JSON status APIs.
+
+Usage: 
+```
+check_json -u|--url <URL> -a|--attribute <attribute> [ -c|--critical <threshold> ] [ -w|--warning <threshold> ] [ -p|--perfvars <fields> ] [ -t|--timeout <timeout> ] [ -d|--divisor <divisor> ] [ -h|--help ]
+```
 
 Example: 
+```
+./check_json.pl --url http://192.168.5.10:9332/local_stats --attribute '{shares}->{dead_shares}' --warning :5 --critical :10 --perfvars '{shares}->{dead_shares},{shares}->{live_shares},{clients}->{clients_connected}'
+```
 
-`check_json.pl -U http://192.168.5.10:9332/local_stats -a '{shares}->{dead}' -w :5 -c :10`
+Result:
+```
+Check JSON status API OK - dead_shares: 2, live_shares: 12, clients_connected: 234 | dead_shares=2;5;10 live_shares=12 clients_connected=234
+```
 
-JSON OK - 2 | value=2;;

check_json.pl

@@ -3,27 +3,32 @@
 use warnings;
 use strict;
 use LWP::UserAgent;
-use JSON 'decode_json';
+use JSON;
 use Nagios::Plugin;
 use Data::Dumper;
 
 my $np = Nagios::Plugin->new(
-    usage => "Usage: %s [ -v|--verbose ] [-U <URL>] [-t <timeout>] "
+    usage => "Usage: %s -u|--url <URL> -a|--attribute <attribute> "
     . "[ -c|--critical <threshold> ] [ -w|--warning <threshold> ] "
-    . "[ -a | --attribute ] <attribute>",
+    . "[ -p|--perfvars <fields> ] "
-    version => '0.1',
+    . "[ -t|--timeout <timeout> ] "
+    . "[ -d|--divisor <divisor> ] "
+    . "[ -h|--help ] ",
+    version => '0.2',
     blurb   => 'Nagios plugin to check JSON attributes via http(s)',
     extra   => "\nExample: \n"
-    . "check_json.pl -U http://192.168.5.10:9332/local_stats -a '{shares}->{dead}' -w :5 -c :10",
+    . "check_json.pl --url http://192.168.5.10:9332/local_stats --attribute '{shares}->{dead}' "
+    . "--warning :5 --critical :10 --perfvars '{shares}->{dead},{shares}->{live}'",
     url     => 'https://github.com/c-kr/check_json',
     plugin  => 'check_json',
     timeout => 15,
+    shortname => "Check JSON status API",
 );
 
  # add valid command line options and build them into your usage/help documentation.
 $np->add_arg(
-    spec => 'URL|U=s',
+    spec => 'url|u=s',
-    help => '-U, --URL http://192.168.5.10:9332/local_stats',
+    help => '-u, --url (eg. http://192.168.5.10:9332/local_stats}',
     required => 1,
 );
 $np->add_arg(
@@ -32,8 +37,8 @@ $np->add_arg(
     required => 1,
 );
 $np->add_arg(
-    spec => 'divisor|D=i',
+    spec => 'divisor|d=i',
-    help => '-D, --divisor 1000000',
+    help => '-d, --divisor 1000000',
 );
 $np->add_arg(
     spec => 'warning|w=s',
@@ -47,21 +52,27 @@ $np->add_arg(
     . 'http://nagiosplug.sourceforge.net/developer-guidelines.html#THRESHOLDFORMAT '
     . 'for the threshold format. ',
 );
+$np->add_arg(
+    spec => 'perfvars|p=s',
+    help => '-p, --perfvars . CSV list of fields from JSON response to include in perfdata '
+    . '{shares}->{dead},{shares}->{live}',
+);
 
-# Parse @ARGV and process standard arguments (e.g. usage, help, version)
+## Parse @ARGV and process standard arguments (e.g. usage, help, version)
 $np->getopts;
-
+if ($np->opts->verbose) { (print Dumper ($np))};
 
 ## GET URL
 my $ua = LWP::UserAgent->new;
 
-$ua->agent('check_json/0.1');
+$ua->agent('check_json/0.2');
 $ua->default_header('Accept' => 'application/json');
 $ua->protocols_allowed( [ 'http', 'https'] );
 $ua->parse_head(0);
 $ua->timeout($np->opts->timeout);
+if ($np->opts->verbose) { (print Dumper ($ua))};
 
-my $response = ($ua->get($np->opts->URL));
+my $response = ($ua->get($np->opts->url));
 
 if ($response->is_success) {
     if (!($response->header("content-type") =~ 'application/json')) {
@@ -71,32 +82,60 @@ if ($response->is_success) {
     $np->nagios_exit(CRITICAL, "Connection failed: ".$response->status_line);
 }
 
+## Parse JSON
 my $json_response = decode_json($response->content);
 if ($np->opts->verbose) { (print Dumper ($json_response))};
 
-my $value;
+my $check_value;
-my $exec = '$value = $json_response->'.$np->opts->attribute;
+my $check_value_str = '$check_value = $json_response->'.$np->opts->attribute;
-if ($np->opts->verbose) {print "EXEC is: $exec \n"};
-eval $exec;
 
-if (!defined $value) {
+if ($np->opts->verbose) { (print Dumper ($check_value_str))};
+eval $check_value_str;
+
+if (!defined $check_value) {
     $np->nagios_exit(UNKNOWN, "No value received");
 }
 
 if (defined $np->opts->divisor) {
-    $value = $value/$np->opts->divisor;
+    $check_value = $check_value/$np->opts->divisor;
 }
 
-my $result = $np->check_threshold($value);
+my $result = $np->check_threshold($check_value);
 
+my @statusmsg;
+
+# routine to add perfdata from JSON response based on a loop of keys given in perfvals (csv)
+if ($np->opts->perfvars) {
+    foreach my $key (split(',', $np->opts->perfvars)) {
+        # use last element of key as label
+        my $label = (split('->', $key))[-1];
+        # make label ascii compatible
+        $label =~ s/[^a-zA-Z0-9_-]//g  ;
+        my $perf_value;
+        $perf_value = eval '$json_response->'.$key;
+        if ($np->opts->verbose) { print Dumper ("JSON key: ".$label.", JSON val: " . $perf_value) };
+        if ( defined($perf_value) ) {
+            # add threshold if attribute option matches key
+            if ($key eq $np->opts->attribute) {
+                push(@statusmsg, "$label: $check_value");
                 $np->add_perfdata(
-    label => 'value',
+                    label => lc $label,
-    value => $value,
+                    value => $check_value,
                     threshold => $np->threshold(),
                 );
+            } else {
+                push(@statusmsg, "$label: $perf_value");
+                $np->add_perfdata(
+                    label => lc $label,
+                    value => $perf_value,
+                );            
+            }
+        }
+    }
+}
 
 $np->nagios_exit(
     return_code => $result,
-    message     => $value,
+    message     => join(', ', @statusmsg),
 );