add vnstat cgi

all/files/vnstat-metrics.cgi

@@ -0,0 +1,118 @@
+#!/usr/bin/perl -w
+
+# vnstat-metrics.cgi -- Prometheus compatible metrics endpoint output from vnStat data
+# copyright (c) 2022 Teemu Toivola <tst at iki dot fi>
+# released under the GNU General Public License
+
+use strict;
+use JSON::PP;
+
+# location of vnstat binary
+my $vnstat_cmd = '/usr/bin/vnstat';
+
+
+################
+
+
+sub get_interface_alias
+{
+	my ($interface) = @_;
+	my $interface_alias = $interface->{'alias'};
+	if (length($interface_alias) == 0) {
+		$interface_alias = $interface->{'name'};
+	}
+	return $interface_alias;
+}
+
+sub print_totals
+{
+	my ($data) = @_;
+
+	print "\n# HELP vnstat_interface_total_received_bytes All time total received (rx) bytes\n";
+	print "# TYPE vnstat_interface_total_received_bytes counter\n";
+
+	foreach my $interface ( @{ $data->{'interfaces'} } ) {
+		my $interface_alias = get_interface_alias($interface);
+		print "vnstat_interface_total_received_bytes{interface=\"$interface->{'name'}\",alias=\"$interface_alias\"} $interface->{'traffic'}{'total'}{'rx'} $interface->{'updated'}{'timestamp'}000\n";
+	}
+
+	print "\n# HELP vnstat_interface_total_transmitted_bytes All time total transmitted (tx) bytes\n";
+	print "# TYPE vnstat_interface_total_transmitted_bytes counter\n";
+
+	foreach my $interface ( @{ $data->{'interfaces'} } ) {
+		my $interface_alias = get_interface_alias($interface);
+		print "vnstat_interface_total_transmitted_bytes{interface=\"$interface->{'name'}\",alias=\"$interface_alias\"} $interface->{'traffic'}{'total'}{'tx'} $interface->{'updated'}{'timestamp'}000\n";
+	}
+}
+
+sub print_data_resolution
+{
+	my ($resolution, $data) = @_;
+	my $output_count = 0;
+
+	print "\n# HELP vnstat_interface_".$resolution."_received_bytes Received (rx) bytes for current $resolution\n";
+	print "# TYPE vnstat_interface_".$resolution."_received_bytes gauge\n";
+
+	$output_count = 0;
+	foreach my $interface ( @{ $data->{'interfaces'} } ) {
+		my $interface_alias = get_interface_alias($interface);
+		if (defined $interface->{'traffic'}{$resolution}) {
+			print "vnstat_interface_".$resolution."_received_bytes{interface=\"$interface->{'name'}\",alias=\"$interface_alias\"} $interface->{'traffic'}{$resolution}[0]{'rx'} $interface->{'updated'}{'timestamp'}000\n";
+			$output_count++;
+		}
+	}
+	if ($output_count == 0) {
+		print "# no data\n";
+	}
+
+	print "\n# HELP vnstat_interface_".$resolution."_transmitted_bytes Transmitted (tx) bytes for current $resolution\n";
+	print "# TYPE vnstat_interface_".$resolution."_transmitted_bytes gauge\n";
+
+	$output_count = 0;
+	foreach my $interface ( @{ $data->{'interfaces'} } ) {
+		my $interface_alias = get_interface_alias($interface);
+		if (defined $interface->{'traffic'}{$resolution}) {
+			print "vnstat_interface_".$resolution."_transmitted_bytes{interface=\"$interface->{'name'}\",alias=\"$interface_alias\"} $interface->{'traffic'}{$resolution}[0]{'tx'} $interface->{'updated'}{'timestamp'}000\n";
+			$output_count++;
+		}
+	}
+	if ($output_count == 0) {
+		print "# no data\n";
+	}
+}
+
+my @data_resolutions = ('fiveminute', 'hour', 'day', 'month', 'year');
+
+print "Content-Type: text/plain\n\n";
+
+my $json_data = `$vnstat_cmd --json s 1`;
+
+my $data = "";
+eval { $data = decode_json($json_data) };
+if ($@) {
+	print "# Error: Invalid command output: $json_data\n";
+	exit 1;
+}
+
+if (not defined $data->{'vnstatversion'}) {
+	print "# Error: Expected content from command output missing\n";
+	exit 1;
+}
+
+if (not defined $data->{'interfaces'}[0]) {
+	print "# Error: No interfaces found in command output\n";
+	exit 1;
+}
+
+if (not defined $data->{'interfaces'}[0]{'created'}{'timestamp'}) {
+	print "# Error: Incompatible vnStat version used\n";
+	exit 1;
+}
+
+print "# vnStat version: ".$data->{'vnstatversion'}."\n";
+
+print_totals($data);
+
+foreach my $data_resolution ( @data_resolutions ) {
+	print_data_resolution($data_resolution, $data);
+}

all/playbook.yaml

@@ -44,6 +44,7 @@
           - apt-file
           - fail2ban
           - tree
+          - perl
           # Monitoring
           - htop
           - gdu
@@ -202,6 +203,20 @@
         validate: "/usr/sbin/sshd -T -f %s"
       notify:
         - Restart sshd
+    - name: Create www directory if doesn't exist already
+      ansible.builtin.file:
+        path: /var/lib/caddy/www
+        state: directory
+        mode: '0755'
+        owner: caddy
+        group: caddy
+    - name: "Instal VNStat Metrics CGI Script to WWW"
+      ansible.builtin.copy:
+        src: ./files/vnstat-metrics.cgi
+        dest: /var/lib/caddy/www/vnstat-metrics.cgi
+        mode: preserve
+        owner: caddy
+        group: caddy
     - name: "Remove useless passphrase line (runs after borgmatic role)"
       ansible.builtin.lineinfile:
         dest: "/etc/borgmatic/config.yaml"

privfrontends/templates/Caddyfile.j2

@@ -1,5 +1,6 @@
 {
 	order rate_limit before basicauth
+	order cgi before respond
 }
 
 (tor) {
@@ -296,3 +297,7 @@ lace.{{ server_prefix }}.projectsegfau.lt lace.projectsegfau.lt l.psf.lt l.{{ se
 	reverse_proxy :9029
 	import torloc lace
 }
+
+:8093 {
+	cgi /vnstat /var/lib/caddy/www/vnstat-metrics.cgi
+}