metrics.php

<?php

// Exports metrics from lg_debug_counters in the Prometheus text format.

require_once('lib/database.class.php');
require_once('config.php');

// value > 0 filters the 'dummy' entry which forces a new revision.
$counters = $database->get_array("SELECT name, UNIX_TIMESTAMP(last_update)*1000 as timestamp, value*mean_duration AS duration FROM lg_debug_counter
	WHERE revision = (SELECT MAX(revision) FROM lg_debug_counter) AND value > 0
	ORDER BY name");

header('Content-Type: text/plain; version=0.0.4');

$type_seen = array();
function print_counter($name, $labels, $duration, $timestamp)
{
	global $type_seen;
	$lstr = '';
	if (count($labels))
	{
		$lstr = '{'. implode(',', array_map(function($k, $v) { return $k.'="'. addcslashes($v, "\"\\\n") .'"'; }, array_keys($labels), $labels)) .'}';
	}
	$metric_name = "league_{$name}_duration_seconds_total";
	if (!in_array($metric_name, $type_seen))
	{
		echo "\n# TYPE $metric_name counter\n";
		$type_seen[] = $metric_name;
	}
	// Don't print timestamps - our metrics are always valid at the time of the scrape.
	//echo "$metric_name$lstr $duration $timestamp\n";
	echo "$metric_name$lstr $duration\n";
}

foreach ($counters as $counter)
{
	$labels = array();
	$name = $counter["name"];
	$name_parts = explode("_", $name, 2);
	switch ($name_parts[0])
	{
	case "site":
		if (count($name_parts) == 2)
		{
			$name = "site";
			list($part, $method) = explode("_", $name_parts[1], 2);
			$labels["part"] = $part;
			$labels["method"] = $method;
		}
		// Skip the "total" counter which can easily be aggregated from the others.
		else continue 2;
		break;
	case "action":
		$name = "backend";
		$labels["action"] = $name_parts[1];
		break;
	}
	print_counter($name, $labels, $counter["duration"], $counter["timestamp"]);
}

global $redis;
if (isset($redis))
{
	$counters = [
		'games_created_total' => [
			'type' => 'counter',
			'desc' => 'total number of games registered with the masterserver',
		],
		'games_ended_total' => [
			'type' => 'counter',
			'desc' => 'total number of games that ended',
		],
		'games_deleted_total' => [
			'type' => 'counter',
			'desc' => 'total number of games that were deleted (excluding those that ended)',
		],
		'games_duration_seconds_total' => [
			'type' => 'counter',
			'desc' => 'total ingame time of all ended games in seconds',
		],
		'sql_errors_total' => [
			'type' => 'counter',
			'desc' => 'total number of entries written to sql_error_log.txt',
		],
		'sql_slow_queries_total' => [
			'type' => 'counter',
			'desc' => 'total number of entries written to sql_slow_log.txt',
		],
	];
	foreach ($counters as $counter => $cfg)
	{
		$counter_name = "league_$counter";
		$counter_value = $redis->get("league:metrics:$counter");
		if (!$counter_value) $counter_value = 0;
		echo "\n# HELP $counter_name $cfg[desc]\n";
		echo "# TYPE $counter_name $cfg[type]\n";
		echo "$counter_name $counter_value\n";
	}
}