Feat: Add Redis watcher (#293)

src/Instrumentation/Laravel/src/Hooks/Illuminate/Foundation/Application.php

@@ -13,6 +13,7 @@
 use OpenTelemetry\Contrib\Instrumentation\Laravel\Watchers\ExceptionWatcher;
 use OpenTelemetry\Contrib\Instrumentation\Laravel\Watchers\LogWatcher;
 use OpenTelemetry\Contrib\Instrumentation\Laravel\Watchers\QueryWatcher;
+use OpenTelemetry\Contrib\Instrumentation\Laravel\Watchers\RedisCommand\RedisCommandWatcher;
 use OpenTelemetry\Contrib\Instrumentation\Laravel\Watchers\Watcher;
 use function OpenTelemetry\Instrumentation\hook;
 use Throwable;
@@ -32,6 +33,7 @@ public function instrument(): void
                 $this->registerWatchers($application, new ExceptionWatcher());
                 $this->registerWatchers($application, new LogWatcher($this->instrumentation));
                 $this->registerWatchers($application, new QueryWatcher($this->instrumentation));
+                $this->registerWatchers($application, new RedisCommandWatcher($this->instrumentation));
             },
         );
     }

src/Instrumentation/Laravel/src/Watchers/RedisCommand/RedisCommandWatcher.php

@@ -0,0 +1,105 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Instrumentation\Laravel\Watchers\RedisCommand;
+
+use Illuminate\Contracts\Foundation\Application;
+use Illuminate\Redis\Connections\Connection;
+use Illuminate\Redis\Connections\PhpRedisConnection;
+use Illuminate\Redis\Connections\PredisConnection;
+use Illuminate\Redis\Events\CommandExecuted;
+use OpenTelemetry\API\Instrumentation\CachedInstrumentation;
+use OpenTelemetry\API\Trace\SpanKind;
+use OpenTelemetry\Contrib\Instrumentation\Laravel\Watchers\Watcher;
+use OpenTelemetry\SemConv\TraceAttributes;
+use OpenTelemetry\SemConv\TraceAttributeValues;
+use Throwable;
+
+/**
+ * Watch the Redis Command event
+ *
+ * Call facade `Redis::enableEvents()` before using this watcher
+ */
+class RedisCommandWatcher extends Watcher
+{
+    public function __construct(
+        private CachedInstrumentation $instrumentation,
+    ) {
+    }
+
+    /** @psalm-suppress UndefinedInterfaceMethod */
+    public function register(Application $app): void
+    {
+        /** @phan-suppress-next-line PhanTypeArraySuspicious */
+        $app['events']->listen(CommandExecuted::class, [$this, 'recordRedisCommand']);
+    }
+
+    /**
+     * Record a Redis command.
+     */
+    /** @psalm-suppress UndefinedThisPropertyFetch */
+    public function recordRedisCommand(CommandExecuted $event): void
+    {
+        $nowInNs = (int) (microtime(true) * 1E9);
+
+        $operationName = strtoupper($event->command);
+
+        /** @psalm-suppress ArgumentTypeCoercion */
+        $span = $this->instrumentation->tracer()
+            ->spanBuilder($operationName)
+            ->setSpanKind(SpanKind::KIND_CLIENT)
+            ->setStartTimestamp($this->calculateQueryStartTime($nowInNs, $event->time))
+            ->startSpan();
+
+        // See https://opentelemetry.io/docs/specs/semconv/database/redis/
+        $attributes = [
+            TraceAttributes::DB_SYSTEM => TraceAttributeValues::DB_SYSTEM_REDIS,
+            TraceAttributes::DB_NAME => $this->fetchDbIndex($event->connection),
+            TraceAttributes::DB_OPERATION => $operationName,
+            TraceAttributes::DB_STATEMENT => Serializer::serializeCommand($event->command, $event->parameters),
+            TraceAttributes::SERVER_ADDRESS => $this->fetchDbHost($event->connection),
+        ];
+
+        /** @psalm-suppress PossiblyInvalidArgument */
+        $span->setAttributes($attributes);
+        $span->end($nowInNs);
+    }
+
+    private function calculateQueryStartTime(int $nowInNs, float $queryTimeMs): int
+    {
+        return (int) ($nowInNs - ($queryTimeMs * 1E6));
+    }
+
+    private function fetchDbIndex(Connection $connection): ?int
+    {
+        try {
+            if ($connection instanceof PhpRedisConnection) {
+                return $connection->client()->getDbNum();
+            } elseif ($connection instanceof PredisConnection) {
+                /** @psalm-suppress PossiblyUndefinedMethod */
+                return $connection->client()->getConnection()->getParameters()->database;
+            }
+
+            return null;
+        } catch (Throwable $e) {
+            return null;
+        }
+    }
+
+    private function fetchDbHost(Connection $connection): ?string
+    {
+        try {
+            if ($connection instanceof PhpRedisConnection) {
+                return $connection->client()->getHost();
+            } elseif ($connection instanceof PredisConnection) {
+                /** @psalm-suppress PossiblyUndefinedMethod */
+                return $connection->client()->getConnection()->getParameters()->host;
+            }
+
+            return null;
+        } catch (Throwable $e) {
+            return null;
+        }
+    }
+}

src/Instrumentation/Laravel/src/Watchers/RedisCommand/Serializer.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Instrumentation\Laravel\Watchers\RedisCommand;
+
+/**
+ * @see https://github.com/open-telemetry/opentelemetry-js-contrib/blob/main/packages/opentelemetry-redis-common/src/index.ts
+ */
+class Serializer
+{
+    /**
+     * List of regexes and the number of arguments that should be serialized for matching commands.
+     * For example, HSET should serialize which key and field it's operating on, but not its value.
+     * Setting the subset to -1 will serialize all arguments.
+     * Commands without a match will have their first argument serialized.
+     *
+     * Refer to https://redis.io/commands/ for the full list.
+     */
+    private const SERIALIZATION_SUBSETS = [
+        [
+            'regex' => '/^ECHO/i',
+            'args' => 0,
+        ],
+        [
+            'regex' => '/^(LPUSH|MSET|PFA|PUBLISH|RPUSH|SADD|SET|SPUBLISH|XADD|ZADD)/i',
+            'args' => 1,
+        ],
+        [
+            'regex' => '/^(HSET|HMSET|LSET|LINSERT)/i',
+            'args' => 2,
+        ],
+        [
+            'regex' => '/^(ACL|BIT|B[LRZ]|CLIENT|CLUSTER|CONFIG|COMMAND|DECR|DEL|EVAL|EX|FUNCTION|GEO|GET|HINCR|HMGET|HSCAN|INCR|L[TRLM]|MEMORY|P[EFISTU]|RPOP|S[CDIMORSU]|XACK|X[CDGILPRT]|Z[CDILMPRS])/i',
+            'args' => -1,
+        ],
+    ];
+
+    /**
+     * Given the redis command name and arguments, return a combination of the
+     * command name + the allowed arguments according to `SERIALIZATION_SUBSETS`.
+     *
+     * @param string $command The redis command name
+     * @param array $params The redis command arguments
+     * @return string A combination of the command name + args according to `SERIALIZATION_SUBSETS`.
+     */
+    public static function serializeCommand(string $command, array $params): string
+    {
+        if (count($params) === 0) {
+            return $command;
+        }
+
+        $paramsToSerializeNum = 0;
+
+        // Find the number of arguments to serialize for the given command
+        foreach (self::SERIALIZATION_SUBSETS as $subset) {
+            if (preg_match($subset['regex'], $command)) {
+                $paramsToSerializeNum = $subset['args'];
+
+                break;
+            }
+        }
+
+        // Serialize the allowed number of arguments
+        $paramsToSerialize = ($paramsToSerializeNum >= 0) ? array_slice($params, 0, $paramsToSerializeNum) : $params;
+
+        // If there are more arguments than serialized, add a placeholder
+        if (count($params) > count($paramsToSerialize)) {
+            $paramsToSerialize[] = '[' . (count($params) - $paramsToSerializeNum) . ' other arguments]';
+        }
+
+        return $command . ' ' . implode(' ', $paramsToSerialize);
+    }
+}

src/Instrumentation/Laravel/tests/Unit/Watches/RedisCommand/SerializerTest.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Tests\Contrib\Instrumentation\Laravel\Unit\Watches\RedisCommand;
+
+use OpenTelemetry\Contrib\Instrumentation\Laravel\Watchers\RedisCommand\Serializer;
+use PHPUnit\Framework\TestCase;
+
+class SerializerTest extends TestCase
+{
+    /**
+     * @dataProvider serializeCases
+     */
+    public function testSerialize($command, $params, $expected): void
+    {
+        $this->assertSame($expected, Serializer::serializeCommand($command, $params));
+    }
+
+    public function serializeCases(): iterable
+    {
+        // Only serialize command
+        yield ['ECHO', ['param1'], 'ECHO [1 other arguments]'];
+
+        // Only serialize 1 params
+        yield ['SET', ['param1', 'param2'], 'SET param1 [1 other arguments]'];
+        yield ['SET', ['param1', 'param2', 'param3'], 'SET param1 [2 other arguments]'];
+
+        // Only serialize 2 params
+        yield ['HSET', ['param1', 'param2', 'param3'], 'HSET param1 param2 [1 other arguments]'];
+
+        // Serialize all params
+        yield ['DEL', ['param1', 'param2', 'param3', 'param4'], 'DEL param1 param2 param3 param4'];
+    }
+}