fix(internal/orchestrion/_integration/fiber.v2): avoid double instrumentation

Author: darccio

contrib/gofiber/fiber.v2/orchestrion.yml

@@ -23,3 +23,17 @@ aspects:
               app.Use(fibertrace.Middleware())
               return app
             }()
+  # Prevent FastHTTP double-instrumentation by marking the underlying server
+  # as already instrumented before Fiber starts listening. This ensures that
+  # when Fiber's internal call to fasthttp.Server.Serve() happens, the
+  # DD_Instrumented flag is already set and the FastHTTP aspect will skip.
+  - id: Listen
+    join-point:
+      function-body:
+        function:
+          - receiver: '*github.com/gofiber/fiber/v2.App'
+          - name: Listen
+    advice:
+      - prepend-statements:
+          template: |
+            {{ .Function.Receiver }}.Server().DD_Instrumented = true

contrib/valyala/fasthttp/orchestrion.yml

@@ -14,9 +14,10 @@ aspects:
     join-point:
       struct-definition: github.com/valyala/fasthttp.Server
     advice:
-      # Add instrumentation flag to prevent double-wrapping
+      # Add instrumentation flag to prevent double-wrapping (exported so frameworks
+      # like Fiber that use FastHTTP internally can set it to prevent double-instrumentation)
       - add-struct-field:
-          name: '__dd_instrumented'
+          name: 'DD_Instrumented'
           type: 'bool'
       # We need to use go:linkname to refer to wrapHandlerWithDefaults in order to avoid creating
       # circular dependencies, as contrib/valyala/fasthttp has a dependency on valyala/fasthttp...
@@ -40,7 +41,7 @@ aspects:
           template: |
             {{ $srv := .Function.Receiver }}
             // Only wrap Handler once, even if Serve() is called multiple times
-            if !{{ $srv }}.__dd_instrumented && {{ $srv }}.Handler != nil {
+            if !{{ $srv }}.DD_Instrumented && {{ $srv }}.Handler != nil {
               {{ $srv }}.Handler = __dd_fasthttptrace_wrapHandler({{ $srv }}.Handler)
-              {{ $srv }}.__dd_instrumented = true
+              {{ $srv }}.DD_Instrumented = true
             }