Runtime connection string

agent/agent-bootstrap/src/main/java/com/microsoft/applicationinsights/agent/bootstrap/BytecodeUtil.java

@@ -54,6 +54,12 @@ public void trackMetric(
     }
   }
 
+  public static void setConnectionString(String connectionString) {
+    if (delegate != null) {
+      delegate.setConnectionString(connectionString);
+    }
+  }
+
   public static void trackEvent(
       @Nullable Date timestamp,
       String name,
@@ -338,6 +344,8 @@ private BytecodeUtil() {}
 
   public interface BytecodeUtilDelegate {
 
+    void setConnectionString(String connectionString);
+
     void trackEvent(
         @Nullable Date timestamp,
         String name,

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/BytecodeUtilImpl.java

@@ -25,6 +25,8 @@
 import com.azure.monitor.opentelemetry.exporter.implementation.utils.FormattedTime;
 import com.azure.monitor.opentelemetry.exporter.implementation.utils.Strings;
 import com.microsoft.applicationinsights.agent.bootstrap.BytecodeUtil.BytecodeUtilDelegate;
+import com.microsoft.applicationinsights.agent.internal.init.RuntimeConfiguration;
+import com.microsoft.applicationinsights.agent.internal.init.RuntimeConfigurator;
 import com.microsoft.applicationinsights.agent.internal.legacyheaders.AiLegacyPropagator;
 import com.microsoft.applicationinsights.agent.internal.statsbeat.FeatureStatsbeat;
 import com.microsoft.applicationinsights.agent.internal.telemetry.TelemetryClient;
@@ -47,10 +49,34 @@ public class BytecodeUtilImpl implements BytecodeUtilDelegate {
 
   private static final AtomicBoolean alreadyLoggedError = new AtomicBoolean();
 
-  public static volatile float samplingPercentage = 100;
+  // in Azure Functions consumption pool, we don't know at startup whether to enable or not
+  public static volatile float samplingPercentage = 0;
 
   public static volatile FeatureStatsbeat featureStatsbeat;
 
+  public static volatile RuntimeConfigurator runtimeConfigurator;
+  public static volatile boolean connectionStringConfiguredAtRuntime;
+
+  @Override
+  public void setConnectionString(String connectionString) {
+    if (!connectionStringConfiguredAtRuntime) {
+      logger.warn(
+          "Using com.microsoft.applicationinsights.connectionstring.ConnectionString.configure()"
+              + " requires setting the json configuration property"
+              + " \"connectionStringConfiguredAtRuntime\" to true");
+      return;
+    }
+    if (TelemetryClient.getActive().getConnectionString() != null) {
+      logger.warn("Connection string is already set");
+      return;
+    }
+    if (runtimeConfigurator != null) {
+      RuntimeConfiguration runtimeConfig = runtimeConfigurator.getCurrentConfigCopy();
+      runtimeConfig.connectionString = connectionString;
+      runtimeConfigurator.apply(runtimeConfig);
+    }
+  }
+
   @Override
   public void trackEvent(
       @Nullable Date timestamp,
@@ -80,7 +106,7 @@ public void trackEvent(
       telemetryBuilder.setTime(FormattedTime.offSetDateTimeFromNow());
     }
     selectivelySetTags(telemetryBuilder, tags);
-    setConnectionString(telemetryBuilder, connectionString, instrumentationKey);
+    setConnectionStringOnTelemetry(telemetryBuilder, connectionString, instrumentationKey);
 
     track(telemetryBuilder, tags, true);
   }
@@ -127,7 +153,7 @@ public void trackMetric(
       telemetryBuilder.setTime(FormattedTime.offSetDateTimeFromNow());
     }
     selectivelySetTags(telemetryBuilder, tags);
-    setConnectionString(telemetryBuilder, connectionString, instrumentationKey);
+    setConnectionStringOnTelemetry(telemetryBuilder, connectionString, instrumentationKey);
 
     track(telemetryBuilder, tags, false);
   }
@@ -182,7 +208,7 @@ public void trackDependency(
       telemetryBuilder.setTime(FormattedTime.offSetDateTimeFromNow());
     }
     selectivelySetTags(telemetryBuilder, tags);
-    setConnectionString(telemetryBuilder, connectionString, instrumentationKey);
+    setConnectionStringOnTelemetry(telemetryBuilder, connectionString, instrumentationKey);
 
     track(telemetryBuilder, tags, true);
   }
@@ -223,7 +249,7 @@ public void trackPageView(
       telemetryBuilder.setTime(FormattedTime.offSetDateTimeFromNow());
     }
     selectivelySetTags(telemetryBuilder, tags);
-    setConnectionString(telemetryBuilder, connectionString, instrumentationKey);
+    setConnectionStringOnTelemetry(telemetryBuilder, connectionString, instrumentationKey);
 
     track(telemetryBuilder, tags, true);
   }
@@ -258,7 +284,7 @@ public void trackTrace(
       telemetryBuilder.setTime(FormattedTime.offSetDateTimeFromNow());
     }
     selectivelySetTags(telemetryBuilder, tags);
-    setConnectionString(telemetryBuilder, connectionString, instrumentationKey);
+    setConnectionStringOnTelemetry(telemetryBuilder, connectionString, instrumentationKey);
 
     track(telemetryBuilder, tags, true);
   }
@@ -312,7 +338,7 @@ public void trackRequest(
       telemetryBuilder.setTime(FormattedTime.offSetDateTimeFromNow());
     }
     selectivelySetTags(telemetryBuilder, tags);
-    setConnectionString(telemetryBuilder, connectionString, instrumentationKey);
+    setConnectionStringOnTelemetry(telemetryBuilder, connectionString, instrumentationKey);
 
     track(telemetryBuilder, tags, true);
   }
@@ -352,7 +378,7 @@ public void trackException(
       telemetryBuilder.setTime(FormattedTime.offSetDateTimeFromNow());
     }
     selectivelySetTags(telemetryBuilder, tags);
-    setConnectionString(telemetryBuilder, connectionString, instrumentationKey);
+    setConnectionStringOnTelemetry(telemetryBuilder, connectionString, instrumentationKey);
 
     track(telemetryBuilder, tags, true);
   }
@@ -403,7 +429,7 @@ public void trackAvailability(
       telemetryBuilder.setTime(FormattedTime.offSetDateTimeFromNow());
     }
     selectivelySetTags(telemetryBuilder, tags);
-    setConnectionString(telemetryBuilder, connectionString, instrumentationKey);
+    setConnectionStringOnTelemetry(telemetryBuilder, connectionString, instrumentationKey);
 
     track(telemetryBuilder, tags, false);
   }
@@ -523,7 +549,7 @@ private static void setOperationTagsFromTheCurrentSpan(
     }
   }
 
-  private static void setConnectionString(
+  private static void setConnectionStringOnTelemetry(
       AbstractTelemetryBuilder telemetryBuilder,
       @Nullable String connectionString,
       @Nullable String instrumentationKey) {

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/classicsdk/ConnectionStringClassFileTransformer.java

@@ -0,0 +1,92 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.microsoft.applicationinsights.agent.internal.classicsdk;
+
+import static org.objectweb.asm.Opcodes.ALOAD;
+import static org.objectweb.asm.Opcodes.ASM9;
+import static org.objectweb.asm.Opcodes.INVOKESTATIC;
+import static org.objectweb.asm.Opcodes.RETURN;
+
+import java.lang.instrument.ClassFileTransformer;
+import java.security.ProtectionDomain;
+import javax.annotation.Nullable;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.MethodVisitor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ConnectionStringClassFileTransformer implements ClassFileTransformer {
+
+  private static final Logger logger =
+      LoggerFactory.getLogger(ConnectionStringClassFileTransformer.class);
+
+  private static final String BYTECODE_UTIL_INTERNAL_NAME =
+      "com/microsoft/applicationinsights/agent/bootstrap/BytecodeUtil";
+
+  private final String unshadedClassName =
+      UnshadedSdkPackageName.get() + "/connectionstring/ConnectionString";
+
+  @Override
+  @Nullable
+  public byte[] transform(
+      @Nullable ClassLoader loader,
+      @Nullable String className,
+      @Nullable Class<?> classBeingRedefined,
+      @Nullable ProtectionDomain protectionDomain,
+      byte[] classfileBuffer) {
+
+    if (!unshadedClassName.equals(className)) {
+      return null;
+    }
+    try {
+      ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
+      ClassVisitor cv = new ConnectionStringClassVisitor(cw);
+      ClassReader cr = new ClassReader(classfileBuffer);
+      cr.accept(cv, 0);
+      return cw.toByteArray();
+    } catch (Throwable t) {
+      logger.error(t.getMessage(), t);
+      return null;
+    }
+  }
+
+  private static class ConnectionStringClassVisitor extends ClassVisitor {
+
+    private final ClassWriter cw;
+
+    private ConnectionStringClassVisitor(ClassWriter cw) {
+      super(ASM9, cw);
+      this.cw = cw;
+    }
+
+    @Override
+    @Nullable
+    public MethodVisitor visitMethod(
+        int access,
+        String name,
+        String descriptor,
+        @Nullable String signature,
+        @Nullable String[] exceptions) {
+      MethodVisitor mv = cw.visitMethod(access, name, descriptor, signature, exceptions);
+      if (name.equals("configure") && descriptor.equals("(Ljava/lang/String;)V")) {
+        mv.visitCode();
+        mv.visitVarInsn(ALOAD, 0);
+        mv.visitMethodInsn(
+            INVOKESTATIC,
+            BYTECODE_UTIL_INTERNAL_NAME,
+            "setConnectionString",
+            "(Ljava/lang/String;)V",
+            false);
+        mv.visitInsn(RETURN);
+        mv.visitMaxs(1, 1);
+        mv.visitEnd();
+        return null;
+      } else {
+        return mv;
+      }
+    }
+  }
+}

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/configuration/Configuration.java

@@ -33,6 +33,11 @@
 public class Configuration {
 
   public String connectionString;
+  // missing connection string will cause the agent to not start up, unless this is set,
+  // in which case the agent will start, but it won't begin capturing any telemetry until the
+  // connection string is configured later on
+  public boolean connectionStringConfiguredAtRuntime =
+      ConfigurationBuilder.inAzureFunctionsConsumptionWorker();
   public Role role = new Role();
   public Map<String, String> customDimensions = new HashMap<>();
   public Sampling sampling = new Sampling();

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/configuration/RpConfiguration.java

@@ -16,11 +16,10 @@ public class RpConfiguration {
 
   public String connectionString;
 
-  // intentionally null, so that we can tell if rp is providing or not
   public Sampling sampling = new Sampling();
 
   // this is needed in Azure Spring Cloud because it will set the role name to application name
   // on behalf of customers by default.
-  // Note the role doesn't support hot load due to unnecessary currently.
+  // Note the role doesn't support hot load currently.
   public Role role = new Role();
 }

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/init/AfterAgentListener.java

@@ -4,31 +4,18 @@
 package com.microsoft.applicationinsights.agent.internal.init;
 
 import com.google.auto.service.AutoService;
-import com.microsoft.applicationinsights.agent.internal.configuration.ConfigurationBuilder;
 import com.microsoft.applicationinsights.agent.internal.httpclient.LazyHttpClient;
 import io.opentelemetry.javaagent.extension.AgentListener;
 import io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdk;
 
 @AutoService(AgentListener.class)
 public class AfterAgentListener implements AgentListener {
 
-  private static volatile AppIdSupplier appIdSupplier;
-
-  public static void setAppIdSupplier(AppIdSupplier appIdSupplier) {
-    AfterAgentListener.appIdSupplier = appIdSupplier;
-  }
-
   @Override
   public void afterAgent(AutoConfiguredOpenTelemetrySdk autoConfiguredOpenTelemetrySdk) {
-    // only safe now to resolve app id because SSL initialization
-    // triggers loading of java.util.logging (starting with Java 8u231)
+    // only safe now to make HTTPS calls because Java SSL classes
+    // trigger loading of java.util.logging (starting with Java 8u231)
     // and JBoss/Wildfly need to install their own JUL manager before JUL is initialized.
-
-    if (!ConfigurationBuilder.inAzureFunctionsConsumptionWorker()) {
-      // Delay registering and starting AppId retrieval until the connection string is available
-      appIdSupplier.updateAppId();
-    }
-
     LazyHttpClient.safeToInitLatch.countDown();
 
     PerformanceCounterInitializer.initialize(FirstEntryPoint.getConfiguration());