Fix azure functions consumption initialization (#3244)

Author: trask

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/diagnostics/DiagnosticsHelper.java

@@ -33,17 +33,20 @@ private DiagnosticsHelper() {}
   }
 
   public static void initRpIntegration(Path agentPath) {
-    if (!Strings.isNullOrEmpty(System.getenv("WEBSITE_SITE_NAME"))) {
+    // important to check FUNCTIONS_WORKER_RUNTIME before WEBSITE_SITE_NAME
+    // TODO (heya) how should we report functions windows users who are using app services
+    //  windows attach by manually setting the env vars (which was the old documented way)
+    if ("java".equals(System.getenv("FUNCTIONS_WORKER_RUNTIME"))) {
+      rpIntegrationChar = 'f';
+      functionsRpIntegration = true;
+      setRpAttachType(agentPath, "functions.codeless");
+    } else if (!Strings.isNullOrEmpty(System.getenv("WEBSITE_SITE_NAME"))) {
       rpIntegrationChar = 'a';
       appSvcRpIntegration = true;
       setRpAttachType(agentPath, "appsvc.codeless");
     } else if (!Strings.isNullOrEmpty(System.getenv("KUBERNETES_SERVICE_HOST"))) {
       rpIntegrationChar = 'k';
       setRpAttachType(agentPath, "aks.codeless");
-    } else if ("java".equals(System.getenv("FUNCTIONS_WORKER_RUNTIME"))) {
-      rpIntegrationChar = 'f';
-      functionsRpIntegration = true;
-      setRpAttachType(agentPath, "functions.codeless");
     } else if (!Strings.isNullOrEmpty(
         System.getenv("APPLICATIONINSIGHTS_SPRINGCLOUD_SERVICE_ID"))) {
       rpIntegrationChar = 's';

agent/instrumentation/azure-functions/src/main/java/io/opentelemetry/javaagent/instrumentation/azurefunctions/FunctionEnvironmentReloadInstrumentation.java

@@ -32,6 +32,12 @@ public void transform(TypeTransformer transformer) {
   public static class ExecuteAdvice {
     @Advice.OnMethodExit(suppress = Throwable.class)
     public static void methodExit() {
+
+      if (System.getenv("AzureWebJobsStorage") == null) {
+        // specialization hasn't occurred yet, and this is just a fake warmup request
+        return;
+      }
+
       AzureFunctions.configureOnce();
     }
   }