support dynamic attach (#13499)

Co-authored-by: Trask Stalnaker <[email protected]>

Author: zeitlinger

javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/OpenTelemetryAgent.java

@@ -15,6 +15,7 @@
 import java.net.URL;
 import java.util.jar.JarFile;
 import java.util.jar.Manifest;
+import javax.annotation.Nullable;
 
 /**
  * Premain-Class for the OpenTelemetry Java agent.
@@ -42,19 +43,20 @@
 public final class OpenTelemetryAgent {
 
   public static void premain(String agentArgs, Instrumentation inst) {
-    startAgent(inst, true);
+    startAgent(inst, agentArgs, true);
   }
 
   public static void agentmain(String agentArgs, Instrumentation inst) {
-    startAgent(inst, false);
+    startAgent(inst, agentArgs, false);
   }
 
-  private static void startAgent(Instrumentation inst, boolean fromPremain) {
+  private static void startAgent(
+      Instrumentation inst, @Nullable String agentArgs, boolean fromPremain) {
     try {
       File javaagentFile = installBootstrapJar(inst);
       InstrumentationHolder.setInstrumentation(inst);
       JavaagentFileHolder.setJavaagentFile(javaagentFile);
-      AgentInitializer.initialize(inst, javaagentFile, fromPremain);
+      AgentInitializer.initialize(inst, javaagentFile, fromPremain, agentArgs);
     } catch (Throwable ex) {
       // Don't rethrow.  We don't have a log manager here, so just print.
       System.err.println("ERROR " + OpenTelemetryAgent.class.getName());

javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/AgentInitializer.java

@@ -28,12 +28,24 @@ public final class AgentInitializer {
   private static boolean isSecurityManagerSupportEnabled = false;
   private static volatile boolean agentStarted = false;
 
-  public static void initialize(Instrumentation inst, File javaagentFile, boolean fromPremain)
+  public static void initialize(
+      Instrumentation inst, File javaagentFile, boolean fromPremain, String agentArgs)
       throws Exception {
     if (agentClassLoader != null) {
       return;
     }
 
+    // this call deliberately uses anonymous class instead of lambda because using lambdas too
+    // early on early jdk8 (see isEarlyOracle18 method) causes jvm to crash. See CrashEarlyJdk8Test.
+    doPrivileged(
+        new PrivilegedAction<Void>() {
+          @Override
+          public Void run() {
+            setSystemProperties(agentArgs);
+            return null;
+          }
+        });
+
     // we expect that at this point agent jar has been appended to boot class path and all agent
     // classes are loaded in boot loader
     if (AgentInitializer.class.getClassLoader() != null) {
@@ -201,4 +213,28 @@ private static AgentStarter createAgentStarter(
   }
 
   private AgentInitializer() {}
+
+  @SuppressWarnings("SystemOut")
+  static void setSystemProperties(@Nullable String agentArgs) {
+    boolean debug = false;
+    if (agentArgs != null && !agentArgs.isEmpty()) {
+      for (String option : agentArgs.split(";")) {
+        int i = option.indexOf('=');
+        if (i < 0) {
+          System.err.println("Malformed agent argument: " + option);
+          continue;
+        }
+
+        String key = option.substring(0, i).trim();
+        String value = option.substring(i + 1).trim();
+        System.setProperty(key, value);
+        if (key.equals("otel.javaagent.debug")) {
+          debug = Boolean.parseBoolean(value);
+        }
+        if (debug) {
+          System.err.println("Setting property [" + key + "] = " + value);
+        }
+      }
+    }
+  }
 }

javaagent-bootstrap/src/test/java/io/opentelemetry/javaagent/bootstrap/AgentInitializerTest.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.bootstrap;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+
+class AgentInitializerTest {
+  @AfterEach
+  void tearDown() {
+    System.clearProperty("foo");
+    System.clearProperty("bar");
+  }
+
+  @Test
+  void agentArgsSystemProperties() {
+    AgentInitializer.setSystemProperties("foo=bar=baz;bar=b,c");
+
+    assertThat(System.getProperty("foo")).isEqualTo("bar=baz");
+    assertThat(System.getProperty("bar")).isEqualTo("b,c");
+  }
+}

smoke-tests/src/test/groovy/io/opentelemetry/smoketest/AppServerTest.groovy

@@ -9,6 +9,8 @@ import io.opentelemetry.proto.trace.v1.Span
 import io.opentelemetry.semconv.ClientAttributes
 import io.opentelemetry.semconv.NetworkAttributes
 import io.opentelemetry.semconv.UrlAttributes
+import io.opentelemetry.testing.internal.armeria.common.HttpMethod
+import io.opentelemetry.testing.internal.armeria.common.RequestHeaders
 import spock.lang.Shared
 import spock.lang.Unroll
 
@@ -34,7 +36,7 @@ abstract class AppServerTest extends SmokeTest {
   def setupSpec() {
     (serverVersion, jdk) = getAppServer()
     isWindows = System.getProperty("os.name").toLowerCase().contains("windows") &&
-      "1" != System.getenv("USE_LINUX_CONTAINERS")
+        "1" != System.getenv("USE_LINUX_CONTAINERS")
 
     // ibm-semeru-runtimes doesn't publish windows images
     // adoptopenjdk is deprecated and doesn't publish Windows 2022 images
@@ -102,7 +104,9 @@ abstract class AppServerTest extends SmokeTest {
     def currentAgentVersion = new JarFile(agentPath).getManifest().getMainAttributes().get(Attributes.Name.IMPLEMENTATION_VERSION)
 
     when:
-    def response = client().get("/app/greeting").aggregate().join()
+    def response = client()
+        .execute(RequestHeaders.of(HttpMethod.GET, "/app/greeting", "X-Test-Request", "test"))
+        .aggregate().join()
     TraceInspector traces = new TraceInspector(waitForTraces())
     Set<String> traceIds = traces.traceIds
     String responseBody = response.contentUtf8()
@@ -141,6 +145,9 @@ abstract class AppServerTest extends SmokeTest {
     and: "Number of spans tagged with expected OS type"
     traces.countFilteredResourceAttributes(OS_TYPE.key, isWindows ? WINDOWS : LINUX) == 3
 
+    and: "Number of spans tagged with attribute set via agentArgs"
+    traces.countFilteredArrayAttributes("http.request.header.x-test-request", "test") == 1
+
     where:
     [appServer, jdk, isWindows] << getTestParams()
   }
@@ -392,7 +399,7 @@ abstract class AppServerTest extends SmokeTest {
 
     responseBody.contains("<script>console.log(hi)</script>")
 
-    if (expectServerSpan()){
+    if (expectServerSpan()) {
       traces.countSpansByKind(Span.SpanKind.SPAN_KIND_SERVER) == 1
       traces.countSpansByName('GET /app/jsp') == 1
     }
@@ -420,7 +427,7 @@ abstract class AppServerTest extends SmokeTest {
 
   protected List<List<Object>> getTestParams() {
     return [
-      [serverVersion, jdk, isWindows]
+        [serverVersion, jdk, isWindows]
     ]
   }
 }

smoke-tests/src/test/groovy/io/opentelemetry/smoketest/TraceInspector.java

@@ -66,6 +66,21 @@ public long countFilteredAttributes(String attributeName, Object attributeValue)
         .count();
   }
 
+  public long countFilteredArrayAttributes(String attributeName, Object attributeValue) {
+    final Object value;
+    if (attributeValue instanceof GString) {
+      value = attributeValue.toString();
+    } else {
+      value = attributeValue;
+    }
+    return getSpanStream()
+        .flatMap(s -> s.getAttributesList().stream())
+        .filter(a -> a.getKey().equals(attributeName))
+        .map(a -> a.getValue().getArrayValue().getValues(0).getStringValue())
+        .filter(s -> s.equals(value))
+        .count();
+  }
+
   public long countFilteredEventAttributes(String attributeName, Object attributeValue) {
     return getSpanStream()
         .flatMap(s -> s.getEventsList().stream())

smoke-tests/src/test/java/io/opentelemetry/smoketest/AbstractTestContainerManager.java

@@ -27,6 +27,8 @@ protected Map<String, String> getAgentEnvironment(
         jvmArgsEnvVarName,
         "-Xmx512m -javaagent:/"
             + TARGET_AGENT_FILENAME
+            // args passed to the agent directly
+            + "=otel.javaagent.debug=true;otel.instrumentation.http.server.capture-request-headers=X-Test-Request"
             // Liberty20Jdk11, Payara6Jdk11 and Payara6Jdk17 fail with
             // java.util.zip.ZipException: Invalid CEN header (invalid zip64 extra data field size)
             + " -Djdk.util.zip.disableZip64ExtraFieldValidation=true");