Merge pull request #13 from open-o11y/LambdaDetector

Add Lambda Detector

Author: bobstrecansky

detectors/LambdaDetector.php

@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Detectors\Aws;
+
+use OpenTelemetry\Sdk\Resource\ResourceConstants;
+use OpenTelemetry\Sdk\Resource\ResourceInfo;
+use OpenTelemetry\Sdk\Trace\Attributes;
+
+/**
+ * The AwsLambdaDetector can be used to detect if a process is running in AWS Lambda
+ * and return a {@link Resource} populated with data about the environment.
+ * Returns an empty Resource if detection fails.
+ */
+class LambdaDetector
+{
+    private const LAMBDA_NAME_ENV = 'AWS_LAMBDA_FUNCTION_NAME';
+    private const LAMBDA_VERSION_ENV = 'AWS_LAMBDA_FUNCTION_VERSION';
+    private const AWS_REGION_ENV = 'AWS_REGION';
+    private const CLOUD_PROVIDER = 'aws';
+
+    public function detect(): ResourceInfo
+    {
+        $lambdaName = getenv(self::LAMBDA_NAME_ENV);
+        $functionVersion = getenv(self::LAMBDA_VERSION_ENV);
+        $awsRegion = getenv(self::AWS_REGION_ENV);
+        
+        // The following ternary operations are created because
+        // the attributes class will only NOT create a variable
+        // when it is set to null. getenv returns false when unsuccessful
+        $lambdaName = $lambdaName ? $lambdaName : null;
+        $functionVersion = $functionVersion ? $functionVersion : null;
+        $awsRegion = $awsRegion ? $awsRegion : null;
+
+        return !$lambdaName && !$awsRegion && !$functionVersion
+            ? ResourceInfo::emptyResource()
+            : ResourceInfo::create(new Attributes([
+                ResourceConstants::FAAS_NAME => $lambdaName,
+                ResourceConstants::FAAS_VERSION => $functionVersion,
+                ResourceConstants::CLOUD_REGION => $awsRegion,
+                ResourceConstants::CLOUD_PROVIDER => self::CLOUD_PROVIDER,
+            ]));
+    }
+}

tests/unit/LambdaDetectorTest.php

@@ -0,0 +1,99 @@
+<?php
+
+declare(strict_types=1);
+
+use Detectors\Aws\LambdaDetector;
+use OpenTelemetry\Sdk\Resource\ResourceConstants;
+use OpenTelemetry\Sdk\Resource\ResourceInfo;
+use OpenTelemetry\Sdk\Trace\Attributes;
+use PHPUnit\Framework\TestCase;
+
+class LambdaDetectorTest extends TestCase
+{
+    private const LAMBDA_NAME_ENV = 'AWS_LAMBDA_FUNCTION_NAME';
+    private const LAMBDA_VERSION_ENV = 'AWS_LAMBDA_FUNCTION_VERSION';
+    private const AWS_REGION_ENV = 'AWS_REGION';
+    private const CLOUD_PROVIDER = 'aws';
+
+    private const LAMBDA_NAME_VAL = 'my-lambda';
+    private const LAMBDA_VERSION_VAL = 'lambda-version';
+    private const AWS_REGION_VAL = 'us-west-1';
+
+    /**
+     * @test
+     */
+    public function TestValidLambda()
+    {
+        putenv(self::LAMBDA_NAME_ENV . '=' . self::LAMBDA_NAME_VAL);
+        putenv(self::LAMBDA_VERSION_ENV . '=' . self::LAMBDA_VERSION_VAL);
+        putenv(self::AWS_REGION_ENV . '=' . self::AWS_REGION_VAL);
+
+        $detector = new LambdaDetector();
+
+        $this->assertEquals(ResourceInfo::create(
+            new Attributes([
+                    ResourceConstants::FAAS_NAME => self::LAMBDA_NAME_VAL,
+                    ResourceConstants::FAAS_VERSION => self::LAMBDA_VERSION_VAL,
+                    ResourceConstants::CLOUD_REGION => self::AWS_REGION_VAL,
+                    ResourceConstants::CLOUD_PROVIDER => self::CLOUD_PROVIDER,
+                ])
+        ), $detector->detect());
+
+        //unset environment variable
+        putenv(self::LAMBDA_NAME_ENV);
+        putenv(self::LAMBDA_VERSION_ENV);
+        putenv(self::AWS_REGION_ENV);
+    }
+
+    /**
+     * @test
+     */
+    public function TestInvalidLambda()
+    {
+        $detector = new LambdaDetector();
+        $this->assertEquals(ResourceInfo::emptyResource(), $detector->detect());
+    }
+
+    /**
+     * @test
+     */
+    public function TestIncompleteLambda1()
+    {
+        putenv(self::LAMBDA_NAME_ENV . '=' . self::LAMBDA_NAME_VAL);
+
+        $detector = new LambdaDetector();
+
+        $this->assertEquals(ResourceInfo::create(
+            new Attributes([
+                    ResourceConstants::FAAS_NAME => self::LAMBDA_NAME_VAL,
+                    ResourceConstants::CLOUD_PROVIDER => self::CLOUD_PROVIDER,
+                ])
+        ), $detector->detect());
+
+        //unset environment variable
+        putenv(self::LAMBDA_NAME_ENV);
+    }
+
+    /**
+     * @test
+     */
+    public function TestIncompleteLambda2()
+    {
+        putenv(self::LAMBDA_NAME_ENV . '=' . self::LAMBDA_NAME_VAL);
+        putenv(self::AWS_REGION_ENV . '=' . self::AWS_REGION_VAL);
+
+        $detector = new LambdaDetector();
+
+        $this->assertEquals(ResourceInfo::create(
+            new Attributes([
+                    ResourceConstants::FAAS_NAME => self::LAMBDA_NAME_VAL,
+                    ResourceConstants::CLOUD_REGION => self::AWS_REGION_VAL,
+                    ResourceConstants::CLOUD_PROVIDER => self::CLOUD_PROVIDER,
+                ])
+        ), $detector->detect());
+
+        //unset environment variable
+        putenv(self::LAMBDA_NAME_ENV);
+        putenv(self::AWS_REGION_ENV);
+    }
+}