[SVLS-8757] Improve cloud environment detection logic

src/main/java/com/datadog/ServerlessCompatAgent.java

@@ -7,6 +7,8 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -16,6 +18,7 @@ enum CloudEnvironment {
     AZURE_FUNCTION,
     AZURE_SPRING_APP,
     GOOGLE_CLOUD_RUN_FUNCTION_1ST_GEN,
+    GOOGLE_CLOUD_RUN_FUNCTION_2ND_GEN,
     UNKNOWN
 }
 
@@ -50,23 +53,39 @@ public static boolean isLinux() {
     }
 
     public static CloudEnvironment getEnvironment() {
-        Map<String, String> env = System.getenv();
+        return getEnvironment(System.getenv());
+    }
+
+    static CloudEnvironment getEnvironment(Map<String, String> env) {
+        List<CloudEnvironment> detected = new ArrayList<>();
 
-        if (env.get("FUNCTIONS_EXTENSION_VERSION") != null &&
-                env.get("FUNCTIONS_WORKER_RUNTIME") != null) {
-            return CloudEnvironment.AZURE_FUNCTION;
+        if (env.get("FUNCTIONS_EXTENSION_VERSION") != null
+                && env.get("FUNCTIONS_WORKER_RUNTIME") != null) {
+            detected.add(CloudEnvironment.AZURE_FUNCTION);
         }
 
         if (env.get("ASCSVCRT_SPRING__APPLICATION__NAME") != null) {
-            return CloudEnvironment.AZURE_SPRING_APP;
+            detected.add(CloudEnvironment.AZURE_SPRING_APP);
         }
 
-        if (env.get("FUNCTION_NAME") != null &&
-                env.get("GCP_PROJECT") != null) {
-            return CloudEnvironment.GOOGLE_CLOUD_RUN_FUNCTION_1ST_GEN;
+        if (env.get("K_SERVICE") != null && env.get("FUNCTION_TARGET") != null) {
+            // Set by Google Cloud Functions for newer runtimes
+            detected.add(CloudEnvironment.GOOGLE_CLOUD_RUN_FUNCTION_2ND_GEN);
+        } else if (env.get("FUNCTION_NAME") != null && env.get("GCP_PROJECT") != null) {
+            // Set by Google Cloud Functions for older runtimes
+            detected.add(CloudEnvironment.GOOGLE_CLOUD_RUN_FUNCTION_1ST_GEN);
+        }
+
+        if (detected.isEmpty()) {
+            return CloudEnvironment.UNKNOWN;
+        }
+        if (detected.size() > 1) {
+            log.error("Multiple cloud environments detected: {}", detected);
+            return CloudEnvironment.UNKNOWN;
         }
 
-        return CloudEnvironment.UNKNOWN;
+        CloudEnvironment environment = detected.get(0);
+        return environment;
     }
 
     public static String getPackageVersion() {

src/test/java/com/datadog/ServerlessCompatAgentTest.java

@@ -0,0 +1,116 @@
+package com.datadog;
+
+import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+import org.slf4j.Logger;
+import org.slf4j.helpers.NOPLogger;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ServerlessCompatAgentTest {
+
+    @ParameterizedTest
+    @CsvSource({
+            "TRACE, TRACE",
+            "DEBUG, DEBUG",
+            "INFO, INFO",
+            "WARN, WARN",
+            "ERROR, ERROR",
+            "CRITICAL, ERROR",
+            "OFF, null"
+    })
+    void testInitLogger(String ddLogLevel, String expectedSlf4jLevel) throws Exception {
+        Method initLoggerMethod = ServerlessCompatAgent.class.getDeclaredMethod("initLogger", String.class);
+        initLoggerMethod.setAccessible(true);
+        Logger logger = (Logger) initLoggerMethod.invoke(null, ddLogLevel);
+
+        if ("OFF".equals(ddLogLevel)) {
+            assertTrue(logger instanceof NOPLogger);
+        } else {
+            assertEquals(expectedSlf4jLevel,
+                    System.getProperty("org.slf4j.simpleLogger.defaultLogLevel"));
+        }
+    }
+
+    @Test
+    void getEnvironment_returnsUnknownWhenNoVarsSet() {
+        assertEquals(CloudEnvironment.UNKNOWN,
+                ServerlessCompatAgent.getEnvironment(new HashMap<>()));
+    }
+
+    @Test
+    void getEnvironment_detectsAzureFunction() {
+        Map<String, String> env = new HashMap<>();
+        env.put("FUNCTIONS_EXTENSION_VERSION", "~4");
+        env.put("FUNCTIONS_WORKER_RUNTIME", "java");
+        assertEquals(CloudEnvironment.AZURE_FUNCTION,
+                ServerlessCompatAgent.getEnvironment(env));
+    }
+
+    @Test
+    void getEnvironment_requiresBothAzureFunctionVars() {
+        Map<String, String> env = new HashMap<>();
+        env.put("FUNCTIONS_EXTENSION_VERSION", "~4");
+        assertEquals(CloudEnvironment.UNKNOWN,
+                ServerlessCompatAgent.getEnvironment(env));
+    }
+
+    @Test
+    void getEnvironment_detectsAzureSpringApp() {
+        Map<String, String> env = new HashMap<>();
+        env.put("ASCSVCRT_SPRING__APPLICATION__NAME", "my-app");
+        assertEquals(CloudEnvironment.AZURE_SPRING_APP,
+                ServerlessCompatAgent.getEnvironment(env));
+    }
+
+    @Test
+    void getEnvironment_detectsGcpOlderRuntimes() {
+        Map<String, String> env = new HashMap<>();
+        env.put("FUNCTION_NAME", "my-function");
+        env.put("GCP_PROJECT", "my-project");
+        assertEquals(CloudEnvironment.GOOGLE_CLOUD_RUN_FUNCTION_1ST_GEN,
+                ServerlessCompatAgent.getEnvironment(env));
+    }
+
+    @Test
+    void getEnvironment_requiresBothGcpOlderRuntimesVars() {
+        Map<String, String> env = new HashMap<>();
+        env.put("FUNCTION_NAME", "my-function");
+        assertEquals(CloudEnvironment.UNKNOWN,
+                ServerlessCompatAgent.getEnvironment(env));
+    }
+
+    @Test
+    void getEnvironment_detectsGcpNewerRuntimes() {
+        Map<String, String> env = new HashMap<>();
+        env.put("K_SERVICE", "my-service");
+        env.put("FUNCTION_TARGET", "handler");
+        assertEquals(CloudEnvironment.GOOGLE_CLOUD_RUN_FUNCTION_2ND_GEN,
+                ServerlessCompatAgent.getEnvironment(env));
+    }
+
+    @Test
+    void getEnvironment_returnsUnknownWhenMultipleEnvironmentsDetected() {
+        Map<String, String> env = new HashMap<>();
+        env.put("FUNCTIONS_EXTENSION_VERSION", "~4");
+        env.put("FUNCTIONS_WORKER_RUNTIME", "java");
+        env.put("FUNCTION_NAME", "my-function");
+        env.put("GCP_PROJECT", "my-project");
+        assertEquals(CloudEnvironment.UNKNOWN,
+                ServerlessCompatAgent.getEnvironment(env));
+    }
+
+    @Test
+    void getEnvironment_bareFunctionNameDoesNotTriggerGcpDetection() {
+        Map<String, String> env = new HashMap<>();
+        env.put("FUNCTION_NAME", "my-function");
+        env.put("FUNCTIONS_EXTENSION_VERSION", "~4");
+        env.put("FUNCTIONS_WORKER_RUNTIME", "java");
+        assertEquals(CloudEnvironment.AZURE_FUNCTION,
+                ServerlessCompatAgent.getEnvironment(env));
+    }
+}