Merge pull request #12 from Clearfacts/CLEARFACTS-8492

[CLEARFACTS-8492] correlation id

README.md

@@ -11,20 +11,16 @@ For more information see [cf-docs](https://github.com/Clearfacts/cf-docs/blob/66
 
 ### Installation
 
-- Make sure you have composer installed globally and have php 7.3 or 7.4
+- Make sure you have composer installed globally and have php 7.4 or higher
 - Clone the project from github
 - `cd <folder-name>`
 - `make init`
 - register the processor 
 
 ```
 Datalog\Processor\SessionRequestProcessor:
-
-        arguments:
-
-            - '@session'
-
-        tags:
-
-            - { name: monolog.processor, method: processRecord }
+    arguments:
+        - '@session'
+    tags:
+        - { name: monolog.processor, method: processRecord }
 ```

src/Correlation/Correlation.php

@@ -0,0 +1,60 @@
+<?php
+declare(strict_types=1);
+
+namespace Datalog\Correlation;
+
+use Symfony\Component\HttpFoundation\RequestStack;
+
+class Correlation
+{
+    private ?RequestStack $requestStack;
+    private static ?string $correlationId = null;
+
+    public function __construct(?RequestStack $requestStack = null)
+    {
+        $this->requestStack = $requestStack;
+    }
+
+    public function init(): void
+    {
+        if (!self::$correlationId) {
+            self::$correlationId = $this->getIdFromRequestStack()
+                ?? $this->getIdFromGlobals()
+                ?? uniqid('cf', true);
+        }
+    }
+
+    public static function setId(?string $correlationId): void
+    {
+        self::$correlationId = $correlationId;
+    }
+
+    public static function getId(): ?string
+    {
+        return self::$correlationId;
+    }
+
+    public function getIdFromRequestStack(): ?string
+    {
+        if (!$this->requestStack) {
+            return null;
+        }
+
+        $request = $this->requestStack->getMainRequest();
+
+        if (!$request) {
+            return null;
+        }
+
+        return $request->headers->get('X-Correlation-ID');
+    }
+
+    public function getIdFromGlobals(): ?string
+    {
+        return $_SERVER['HTTP_X_CORRELATION_ID']
+            ?? $_SERVER['X_CORRELATION_ID']
+            ?? $_SERVER['CORRELATION_ID']
+            ?? $_ENV['CORRELATION_ID']
+            ?? null;
+    }
+}

src/Processor/CorrelationProcessor.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Datalog\Processor;
+
+use Datalog\Correlation\Correlation;
+use Monolog\Processor\ProcessorInterface;
+
+class CorrelationProcessor implements ProcessorInterface
+{
+    private Correlation $correlation;
+
+    public function __construct(Correlation $correlation)
+    {
+        $this->correlation = $correlation;
+    }
+
+    public function __invoke(array $record): array
+    {
+        $this->correlation->init();
+
+        $record['extra']['correlation_id'] = $this->correlation::getId();
+
+        return $record;
+    }
+}

tests/Correlation/CorrelationTest.php

@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Datalog\Correlation;
+
+use Datalog\Correlation\Correlation;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\RequestStack;
+use Tests\Datalog\TestCase;
+
+class CorrelationTest extends TestCase
+{
+    private Correlation $correlation;
+    private RequestStack $requestStack;
+
+    protected function setUp(): void
+    {
+        $this->requestStack = new RequestStack();
+        $this->correlation = new Correlation($this->requestStack);
+        $this->correlation::setId(null);
+    }
+
+    public function testInit(): void
+    {
+        $this->assertEmpty($this->correlation::getId());
+
+        $this->correlation->init();
+
+        $this->assertNotEmpty($this->correlation::getId());
+
+        $firstId = $this->correlation::getId();
+        $this->correlation->init();
+
+        $this->assertSame($firstId, $this->correlation::getId());
+    }
+
+    public function testInitPrefersRequestStack(): void
+    {
+        $_SERVER['HTTP_X_CORRELATION_ID'] = 'test server';
+        $request = new Request();
+        $request->headers->set('X-Correlation-ID', 'test request');
+        $this->requestStack->push($request);
+
+        $this->correlation->init();
+
+        $this->assertSame('test request', $this->correlation::getId());
+    }
+
+    public function testInitFallsBackToGlobals(): void
+    {
+        $_SERVER['HTTP_X_CORRELATION_ID'] = 'test server';
+        $request = new Request();
+        $this->requestStack->push($request);
+
+        $this->correlation->init();
+
+        $this->assertSame('test server', $this->correlation::getId());
+    }
+}