From 435f13b3b584f5e7d1605e80978ea8ec7f57b889 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Carlos=20Ch=C3=A1vez?= <jcchavezs@gmail.com>
Date: Sat, 20 Jun 2020 12:06:35 +0200
Subject: [PATCH] chore: uses HTTP instrumentation from Zipkin PHP.

---
 backend.php   | 15 +++++++++++++--
 composer.json |  9 +++++----
 frontend.php  | 30 +++++++++++-------------------
 3 files changed, 29 insertions(+), 25 deletions(-)

diff --git a/backend.php b/backend.php
index 216d23b..9027d09 100644
--- a/backend.php
+++ b/backend.php
@@ -1,6 +1,7 @@
 <?php
 
 use Zipkin\Propagation\Map;
+use Zipkin\Propagation\TraceContext;
 
 require_once __DIR__ . '/vendor/autoload.php';
 require_once __DIR__ . '/functions.php';
@@ -9,6 +10,8 @@
 
 $request = \Symfony\Component\HttpFoundation\Request::createFromGlobals();
 
+usleep(1000 * mt_rand(1, 3));
+
 $carrier = array_map(function ($header) {
     return $header[0];
 }, $request->headers->all());
@@ -19,20 +22,28 @@
 
 /* Get users from DB */
 $tracer = $tracing->getTracer();
-$span = $tracer->nextSpan($extractedContext);
+
+$span = $extractedContext instanceof TraceContext
+    ? $tracer->joinSpan($extractedContext)
+    : $tracer->nextSpan($extractedContext);
+
 $span->start();
 $span->setKind(Zipkin\Kind\SERVER);
 $span->setName('parse_request');
+usleep(1000 * mt_rand(1, 3));
 
 $childSpan = $tracer->newChild($span->getContext());
 $childSpan->start();
 $childSpan->setKind(Zipkin\Kind\CLIENT);
 $childSpan->setName('user:get_list:mysql_query');
+$childSpan->tag("sql.query", "SELECT * FROM users LIMIT 10");
 
-usleep(50000);
+usleep(30000);
 
 $childSpan->finish();
 
+usleep(1000 * mt_rand(1, 3));
+
 $span->finish();
 
 /* Sends the trace to zipkin once the response is served */
diff --git a/composer.json b/composer.json
index 2ad7242..39be3ec 100644
--- a/composer.json
+++ b/composer.json
@@ -2,9 +2,10 @@
     "name": "openzipkin/zipkin-php-example",
     "require": {
         "monolog/monolog": "^1.23",
-        "guzzlehttp/guzzle": "^6.3",
-        "openzipkin/zipkin": "^1.2.2",
-        "symfony/http-foundation": "3.4.x-dev"
+        "guzzlehttp/guzzle": "7.0.0-RC.1",
+        "openzipkin/zipkin": "dev-http_tracing",
+        "symfony/http-foundation": "3.4.x-dev",
+        "psr/http-client": "^1.0"
     },
     "minimum-stability": "stable",
     "authors": [
@@ -18,4 +19,4 @@
         "run-backend": "php -S 'localhost:9000' backend.php",
         "run-zipkin": "docker run -p 9411:9411 -d openzipkin/zipkin"
     }
-}
+}
\ No newline at end of file
diff --git a/frontend.php b/frontend.php
index b59a053..c92a4cd 100644
--- a/frontend.php
+++ b/frontend.php
@@ -2,8 +2,8 @@
 
 use GuzzleHttp\Client;
 use Zipkin\Propagation\DefaultSamplingFlags;
-use Zipkin\Propagation\Map;
 use Zipkin\Timestamp;
+use Zipkin\Instrumentation\Http\Client\Client as ZipkinClient;
 
 require_once __DIR__ . '/vendor/autoload.php';
 require_once __DIR__ . '/functions.php';
@@ -21,30 +21,22 @@
 $span->setName('parse_request');
 $span->setKind(Zipkin\Kind\SERVER);
 
-usleep(100 * mt_rand(1, 3));
-
-/* Creates the span for getting the users list */
-$childSpan = $tracer->newChild($span->getContext());
-$childSpan->start();
-$childSpan->setKind(Zipkin\Kind\CLIENT);
-$childSpan->setName('users:get_list');
+// We need to open a scope so the http client can retrieve the current
+// context from it.
+$scopeCloser = $tracer->openScope($span);
 
-$headers = [];
+usleep(100 * mt_rand(1, 3));
 
-/* Injects the context into the wire */
-$injector = $tracing->getPropagation()->getInjector(new Map());
-$injector($childSpan->getContext(), $headers);
+$httpClient = new ZipkinClient(new Client, $tracing);
+$request = new \GuzzleHttp\Psr7\Request('POST', 'localhost:9000');
+$response = $httpClient->sendRequest($request);
 
-/* HTTP Request to the backend */
-$httpClient = new Client();
-$request = new \GuzzleHttp\Psr7\Request('POST', 'localhost:9000', $headers);
-$childSpan->annotate('request_started', Timestamp\now());
-$response = $httpClient->send($request);
-$childSpan->annotate('request_finished', Timestamp\now());
+echo $response->getBody();
 
-$childSpan->finish();
+usleep(100 * mt_rand(1, 3));
 
 $span->finish();
+$scopeCloser();
 
 /* Sends the trace to zipkin once the response is served */