dkx/google-tracer

This package is abandoned and no longer maintained. No replacement package was suggested.

Wrapper for Google Trace library

1.0.0 2020-01-19 16:04 UTC

Requires

• php: >=7.3
• google/cloud-trace: ^0.16
• psr/http-message: ^1.0
• psr/http-server-middleware: ^1.0
• psr/simple-cache: ^1.0
• ramsey/uuid: ^3.9

Requires (Dev)

• mockery/mockery: ^1.3
• phpstan/extension-installer: >=1.0
• phpstan/phpstan: >=0.11
• phpstan/phpstan-phpunit: >=0.11
• phpstan/phpstan-strict-rules: >=0.11
• phpunit/phpunit: >=8.0

MIT

• David Kudera

README

Wrapper for Google Trace library

Only for psr7 applications

Installation

$ composer require dkx/google-tracer

Basic usage

<?php

use DKX\GoogleTracer\Exporter\GoogleTraceExporter;
use DKX\GoogleTracer\Sampler\AlwaysSampler;
use DKX\GoogleTracer\Tracer;
use Google\Cloud\Trace\TraceClient;

$projectName = 'my-app/production';
$projectVersion = '0.0.1';

$traceClient = new TraceClient();
$exporter = new GoogleTraceExporter($traceClient);
$sampler = new AlwaysSampler();
$tracer = new Tracer($exporter, $sampler, $projectName, $projectVersion);

$trace = $tracer->start();
$request = getCurrentHttpRequestSomehow();

try {
    $response = getCurrentHttpResponseSomehow($request);
    $tracer->finishSuccessfully($trace, $request, $response);
} catch(\Throwable $e) {
    $tracer->finishWithError($trace, $request, $e);
}

Create sub-spans

<?php

use DKX\GoogleTracer\Span;

$trace->span('controller', function (Span $span): void {
    $users = $span->span('users.load', function (Span $span): array {
        $users = $span->span('users.load.fromCache', function (Span $span): ?array {
            return tryToLoadUsersFromCache();        
        });
        
        if ($users === null) {
            $users = $span->span('users.load.fromDatabase', function (Span $span): array {
                return loadUsersFromDatabase();
            });

            $span->span('users.load.saveCache', function (Span $span) use ($users): void {
                saveUsersToCache($users);
            });
        }

        return $users;
    });

    var_dump($users);
});

PSR15 middleware

<?php

use DKX\GoogleTracer\Psr15\TracerControllerSpanMiddleware;

$middleware = new TracerControllerSpanMiddleware($trace);

This will automatically register a controller span into $trace (can be replaced with span). Created span is added into http request's attributes.

<?php

use DKX\GoogleTracer\Psr15\TracerControllerSpanMiddleware;

/** @var \DKX\GoogleTracer\Span $span */
$span = $request->getAttribute(TracerControllerSpanMiddleware::CONTROLLER_SPAN);
$span->span('inside-of-controller', function (): void {
    // todo: watched span in a controller
});

Or you can use dynamic middleware which will load parent trace or span from http request attribute:

<?php

use DKX\GoogleTracer\Psr15\TracerControllerSpanDynamicMiddleware;

$request = getCurrentHttpRequestSomehow();
$request->withAttribute('controllerSpanParent', $trace);

$middleware = new TracerControllerSpanDynamicMiddleware('controllerSpanParent');

Exporters

• DKX\GoogleTracer\Exporter\GoogleTraceExporter: save trace data into Google Cloud Trace
• DKX\GoogleTracer\Exporter\VoidExporter: "do nothing" exporter

Samplers

• DKX\GoogleTracer\Sampler\AlwaysSampler: save traces for all requests
• DKX\GoogleTracer\Sampler\NeverSampler: don't save any traces
• DKX\GoogleTracer\Sampler\ProbabilitySampler($rate): save traces based on probability rate (0 <> 1)
• DKX\GoogleTracer\Sampler\QpsSampler($cache, $cacheKey, $rate): save traces based on queries per second rate (0 <> 1)