Fix debugger start when endpoints aren't available

catch exception throws during common init and keep the product stopped
SymDB, Exception Replay and Code Origin requires CommonInit which
may in some cases throw exception (endpoints are not available from Datadog Agent)

Author: jpbempel

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/agent/DebuggerAgent.java

@@ -110,38 +110,44 @@ public static synchronized void run(
     TracerFlare.addReporter(DebuggerAgent::addReportToFlare);
   }
 
-  private static void commonInit(Config config) {
+  private static boolean commonInit(Config config) {
     if (!commonInitDone.compareAndSet(false, true)) {
-      return;
+      return true;
+    }
+    try {
+      configurationPoller = sharedCommunicationObjects.configurationPoller(config);
+      Redaction.addUserDefinedKeywords(config);
+      Redaction.addUserDefinedTypes(config);
+      DDAgentFeaturesDiscovery ddAgentFeaturesDiscovery =
+          sharedCommunicationObjects.featuresDiscovery(config);
+      ddAgentFeaturesDiscovery.discoverIfOutdated();
+      agentVersion = ddAgentFeaturesDiscovery.getVersion();
+      String diagnosticEndpoint = getDiagnosticEndpoint(config, ddAgentFeaturesDiscovery);
+      ProbeStatusSink probeStatusSink =
+          new ProbeStatusSink(
+              config, diagnosticEndpoint, ddAgentFeaturesDiscovery.supportsDebuggerDiagnostics());
+      DebuggerSink debuggerSink =
+          createDebuggerSink(config, ddAgentFeaturesDiscovery, probeStatusSink);
+      debuggerSink.start();
+      configurationUpdater =
+          new ConfigurationUpdater(
+              instrumentation,
+              DebuggerAgent::createTransformer,
+              config,
+              debuggerSink,
+              classesToRetransformFinder);
+      sink = debuggerSink;
+      DebuggerContext.initProbeResolver(configurationUpdater);
+      DebuggerContext.initMetricForwarder(new StatsdMetricForwarder(config, probeStatusSink));
+      DebuggerContext.initClassFilter(new DenyListHelper(null)); // default hard coded deny list
+      snapshotSerializer = new JsonSnapshotSerializer();
+      DebuggerContext.initValueSerializer(snapshotSerializer);
+      DebuggerContext.initTracer(new DebuggerTracer(debuggerSink.getProbeStatusSink()));
+      return true;
+    } catch (Exception ex) {
+      LOGGER.debug("Failed to init common component for debugger agent", ex);
+      return false;
     }
-    configurationPoller = sharedCommunicationObjects.configurationPoller(config);
-    Redaction.addUserDefinedKeywords(config);
-    Redaction.addUserDefinedTypes(config);
-    DDAgentFeaturesDiscovery ddAgentFeaturesDiscovery =
-        sharedCommunicationObjects.featuresDiscovery(config);
-    ddAgentFeaturesDiscovery.discoverIfOutdated();
-    agentVersion = ddAgentFeaturesDiscovery.getVersion();
-    String diagnosticEndpoint = getDiagnosticEndpoint(config, ddAgentFeaturesDiscovery);
-    ProbeStatusSink probeStatusSink =
-        new ProbeStatusSink(
-            config, diagnosticEndpoint, ddAgentFeaturesDiscovery.supportsDebuggerDiagnostics());
-    DebuggerSink debuggerSink =
-        createDebuggerSink(config, ddAgentFeaturesDiscovery, probeStatusSink);
-    debuggerSink.start();
-    configurationUpdater =
-        new ConfigurationUpdater(
-            instrumentation,
-            DebuggerAgent::createTransformer,
-            config,
-            debuggerSink,
-            classesToRetransformFinder);
-    sink = debuggerSink;
-    DebuggerContext.initProbeResolver(configurationUpdater);
-    DebuggerContext.initMetricForwarder(new StatsdMetricForwarder(config, probeStatusSink));
-    DebuggerContext.initClassFilter(new DenyListHelper(null)); // default hard coded deny list
-    snapshotSerializer = new JsonSnapshotSerializer();
-    DebuggerContext.initValueSerializer(snapshotSerializer);
-    DebuggerContext.initTracer(new DebuggerTracer(debuggerSink.getProbeStatusSink()));
   }
 
   private static void initClassNameFilter() {
@@ -155,7 +161,10 @@ public static void startDynamicInstrumentation(Config config) {
       return;
     }
     LOGGER.info("Starting Dynamic Instrumentation");
-    commonInit(config);
+    if (!commonInit(config)) {
+      dynamicInstrumentationEnabled.set(false);
+      return;
+    }
     String probeFileLocation = config.getDynamicInstrumentationProbeFile();
     if (probeFileLocation != null) {
       Path probeFilePath = Paths.get(probeFileLocation);
@@ -205,7 +214,10 @@ public static void startSymbolDatabase(Config config) {
       return;
     }
     LOGGER.debug("Starting Symbol Database");
-    commonInit(config);
+    if (!commonInit(config)) {
+      symDBEnabled.set(false);
+      return;
+    }
     initClassNameFilter();
     List<ScopeFilter> scopeFilters =
         Arrays.asList(new AvroFilter(), new ProtoFilter(), new WireFilter());
@@ -254,7 +266,10 @@ public static void startExceptionReplay(Config config) {
       return;
     }
     LOGGER.info("Starting Exception Replay");
-    commonInit(config);
+    if (!commonInit(config)) {
+      exceptionReplayEnabled.set(false);
+      return;
+    }
     initClassNameFilter();
     if (config.isCiVisibilityEnabled()) {
       exceptionDebugger =
@@ -285,7 +300,10 @@ public static void startCodeOriginForSpans(Config config) {
       return;
     }
     LOGGER.debug("Starting Code Origin for spans");
-    commonInit(config);
+    if (!commonInit(config)) {
+      codeOriginEnabled.set(false);
+      return;
+    }
     initClassNameFilter();
     DebuggerContext.initClassNameFilter(classNameFilter);
     DebuggerContext.initCodeOrigin(new DefaultCodeOriginRecorder(config, configurationUpdater));

dd-smoke-tests/debugger-integration-tests/src/test/java/datadog/smoketest/BaseIntegrationTest.java

@@ -95,7 +95,7 @@ public abstract class BaseIntegrationTest {
   public static final String APM_TRACING_PRODUCT = "APM_TRACING";
 
   protected MockWebServer datadogAgentServer;
-  private MockDispatcher probeMockDispatcher;
+  protected MockDispatcher probeMockDispatcher;
   private StatsDServer statsDServer;
   private HttpUrl probeUrl;
   private HttpUrl snapshotUrl;
@@ -410,7 +410,7 @@ protected String retrieveStatsdMessage(String str) {
     return statsDServer.waitForMessage(str);
   }
 
-  private MockResponse datadogAgentDispatch(RecordedRequest request) {
+  protected MockResponse datadogAgentDispatch(RecordedRequest request) {
     LOG.info("datadogAgentDispatch request path: {}", request.getPath());
     if (request.getPath().equals("/info")) {
       return AGENT_INFO_RESPONSE;
@@ -591,7 +591,7 @@ protected static boolean logHasErrors(Path logFilePath, Function<String, Boolean
     }
   }
 
-  private static class MockDispatcher extends okhttp3.mockwebserver.QueueDispatcher {
+  protected static class MockDispatcher extends okhttp3.mockwebserver.QueueDispatcher {
     private Function<RecordedRequest, MockResponse> dispatcher;
 
     @Override

dd-smoke-tests/debugger-integration-tests/src/test/java/datadog/smoketest/InProductEnablementIntegrationTest.java

@@ -6,6 +6,8 @@
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.RecordedRequest;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
@@ -90,6 +92,30 @@ void testExceptionReplayEnablement() throws Exception {
     waitForReTransformation(appUrl); // wait for retransformation of removed probes
   }
 
+  // TODO test for failure of starting ER, SymDB and DI: should degrade gracefully
+  // TODO by not providing endpoints
+
+  @Test
+  @DisplayName("testExceptionReplayEnablementFailure")
+  void testExceptionReplayEnablementFailure() throws Exception {
+    additionalJvmArgs.add("-Ddd.symbol.database.upload.enabled=false"); // enabled by default
+    additionalJvmArgs.add("-Ddd.exception.replay.enabled=true");
+    additionalJvmArgs.add("-Ddd.third.party.excludes=datadog.smoketest");
+    this.probeMockDispatcher.setDispatcher(this::noEndpointDispatch);
+    appUrl = startAppAndAndGetUrl();
+    waitForSpecificLine(appUrl, "Failed to init common component for debugger agent");
+  }
+
+  private MockResponse noEndpointDispatch(RecordedRequest request) {
+    if (request.getPath().equals("/info")) {
+      // no debugger endpoints
+      String info =
+          "{\"endpoints\": [\"" + TRACE_URL_PATH + "\", \"" + LOG_UPLOAD_URL_PATH + "\"]}";
+      return new MockResponse().setResponseCode(200).setBody(info);
+    }
+    return datadogAgentDispatch(request);
+  }
+
   private void waitForFeatureStarted(String appUrl, String feature) throws IOException {
     String line = "INFO com.datadog.debugger.agent.DebuggerAgent - Started " + feature;
     waitForSpecificLine(appUrl, line);