[9.x] Share logging context across channels and stacks (#42276)

* allow context to be shared across channels and stacks

* add ability to flush the shared context

* formatting
"

Co-authored-by: Taylor Otwell <[email protected]>

Author: timacdonald

src/Illuminate/Log/LogManager.php

@@ -51,6 +51,13 @@ class LogManager implements LoggerInterface
      */
     protected $dateFormat = 'Y-m-d H:i:s';
 
+    /**
+     * The context shared across channels and stacks.
+     *
+     * @var array
+     */
+    protected $sharedContext = [];
+
     /**
      * Create a new Log manager instance.
      *
@@ -84,10 +91,10 @@ public function build(array $config)
      */
     public function stack(array $channels, $channel = null)
     {
-        return new Logger(
+        return (new Logger(
             $this->createStackDriver(compact('channels', 'channel')),
             $this->app['events']
-        );
+        ))->withContext($this->sharedContext);
     }
 
     /**
@@ -123,7 +130,7 @@ protected function get($name, ?array $config = null)
     {
         try {
             return $this->channels[$name] ?? with($this->resolve($name, $config), function ($logger) use ($name) {
-                return $this->channels[$name] = $this->tap($name, new Logger($logger, $this->app['events']));
+                return $this->channels[$name] = $this->tap($name, new Logger($logger, $this->app['events']))->withContext($this->sharedContext);
             });
         } catch (Throwable $e) {
             return tap($this->createEmergencyLogger(), function ($logger) use ($e) {
@@ -438,6 +445,45 @@ protected function formatter()
         });
     }
 
+    /**
+     * Share context across channels and stacks.
+     *
+     * @param  array  $context
+     * @return $this
+     */
+    public function shareContext(array $context)
+    {
+        foreach ($this->channels as $channel) {
+            $channel->withContext($context);
+        }
+
+        $this->sharedContext = array_merge($this->sharedContext, $context);
+
+        return $this;
+    }
+
+    /**
+     * The context shared across channels and stacks.
+     *
+     * @return array
+     */
+    public function sharedContext()
+    {
+        return $this->sharedContext;
+    }
+
+    /**
+     * Flush the shared context.
+     *
+     * @return array
+     */
+    public function flushSharedContext()
+    {
+        $this->sharedContext = [];
+
+        return $this;
+    }
+
     /**
      * Get fallback log channel name.
      *

src/Illuminate/Support/Facades/Log.php

@@ -8,6 +8,8 @@
  * @method static \Psr\Log\LoggerInterface build(array $config)
  * @method static \Illuminate\Log\Logger withContext(array $context = [])
  * @method static \Illuminate\Log\Logger withoutContext()
+ * @method static \Illuminate\Log\LogManager shareContext(array $context)
+ * @method static array sharedContext()
  * @method static void alert(string $message, array $context = [])
  * @method static void critical(string $message, array $context = [])
  * @method static void debug(string $message, array $context = [])

tests/Log/LogManagerTest.php

@@ -481,4 +481,95 @@ public function testWrappingHandlerInFingersCrossedWhenActionLevelIsUsed()
         $this->assertInstanceOf(StreamHandler::class, $expectedStreamHandler);
         $this->assertEquals(Monolog::DEBUG, $expectedStreamHandler->getLevel());
     }
+
+    public function testItSharesContextWithAlreadyResolvedChannels()
+    {
+        $manager = new LogManager($this->app);
+        $channel = $manager->channel('single');
+        $context = null;
+
+        $channel->listen(function ($message) use (&$context) {
+            $context = $message->context;
+        });
+        $manager->shareContext([
+            'invocation-id' => 'expected-id',
+        ]);
+        $channel->info('xxxx');
+
+        $this->assertSame(['invocation-id' => 'expected-id'], $context);
+    }
+
+    public function testItSharesContextWithFreshlyResolvedChannels()
+    {
+        $manager = new LogManager($this->app);
+        $context = null;
+
+        $manager->shareContext([
+            'invocation-id' => 'expected-id',
+        ]);
+        $manager->channel('single')->listen(function ($message) use (&$context) {
+            $context = $message->context;
+        });
+        $manager->channel('single')->info('xxxx');
+
+        $this->assertSame(['invocation-id' => 'expected-id'], $context);
+    }
+
+    public function testContextCanBePublicallyAccessedByOtherLoggingSystems()
+    {
+        $manager = new LogManager($this->app);
+        $context = null;
+
+        $manager->shareContext([
+            'invocation-id' => 'expected-id',
+        ]);
+
+        $this->assertSame($manager->sharedContext(), ['invocation-id' => 'expected-id']);
+    }
+
+    public function testItSharesContextWithStacksWhenTheyAreResolved()
+    {
+        $manager = new LogManager($this->app);
+        $context = null;
+
+        $manager->shareContext([
+            'invocation-id' => 'expected-id',
+        ]);
+        $stack = $manager->stack(['single']);
+        $stack->listen(function ($message) use (&$context) {
+            $context = $message->context;
+        });
+        $stack->info('xxxx');
+
+        $this->assertSame(['invocation-id' => 'expected-id'], $context);
+    }
+
+    public function testItMergesSharedContextRatherThanReplacing()
+    {
+        $manager = new LogManager($this->app);
+        $context = null;
+
+        $manager->shareContext([
+            'invocation-id' => 'expected-id',
+        ]);
+        $manager->shareContext([
+            'invocation-start' => 1651800456,
+        ]);
+        $manager->channel('single')->listen(function ($message) use (&$context) {
+            $context = $message->context;
+        });
+        $manager->channel('single')->info('xxxx', [
+            'logged' => 'context',
+        ]);
+
+        $this->assertSame([
+            'invocation-id' => 'expected-id',
+            'invocation-start' => 1651800456,
+            'logged' => 'context',
+        ], $context);
+        $this->assertSame([
+            'invocation-id' => 'expected-id',
+            'invocation-start' => 1651800456,
+        ], $manager->sharedContext());
+    }
 }