refining the example; cleaning up XXXs in the instr

examples/an-azure-function-app/README.md

@@ -45,7 +45,7 @@ APM agent. The App has a single function:
 4. Call your functions:
 
     ```
-    curl -i https://<APP_NAME>.azurewebsites.net/api/hi
+    curl -i https://<APP_NAME>.azurewebsites.net/api/hello
     ```
 
 The result (after a minute for data to propagate) should be a `<APP_NAME>` service

examples/an-azure-function-app/src/functions/Hi.js → examples/an-azure-function-app/src/functions/Hello.js

@@ -1,12 +1,12 @@
 const { app } = require('@azure/functions');
 
-app.http('Hi', {
+app.http('Hello', {
   methods: ['GET'],
   authLevel: 'anonymous',
-  handler: async (request, _context) => {
+  handler: async (_request, _context) => {
     const url = new URL('http://worldtimeapi.org/api/timezone/America/Vancouver');
-    const timeRes = await fetch(url);
-    const timeBody = await byeRes.json();
+    const timeRes = await fetch(url, { signal: AbortSignal.timeout(5000) });
+    const timeBody = await timeRes.json();
 
     const body = JSON.stringify({
       hello: 'world',

lib/instrumentation/azure-functions.js

@@ -355,8 +355,6 @@ function instrument(agent) {
     }
 
     const context = hookCtx.invocationContext;
-    console.log('XXX context:');
-    console.dir(context, { depth: 50 }); // XXX
     const invocationId = context.invocationId;
     log.trace({ invocationId }, 'azure-functions: preInvocation');
 
@@ -365,18 +363,19 @@ function instrument(agent) {
       isFirstRun = false;
     }
 
-    // XXX https://github.com/elastic/apm-agent-nodejs/pull/4178/files for azfunc v4
+    // In programming model v3 the InvocationContext includes
+    // `bindingDefinitions` and `executionContext`. In v4 the structure is a
+    // little different.
     let bindingDefinitions = context.bindingDefinitions;
     if (!bindingDefinitions) {
-      // cater for possibly v4 version of the function app
       bindingDefinitions = [];
-      // push input bindings
+      // Input bindings
       bindingDefinitions.push({
         name: context?.options?.trigger?.name,
         type: context?.options?.trigger?.type,
         direction: context?.options?.trigger?.direction,
       });
-      // push the output bindings
+      // Output bindings
       bindingDefinitions.push(context?.options?.return);
     }
     let executionContext = context.executionContext;
@@ -394,22 +393,6 @@ function instrument(agent) {
     ));
     const triggerType = funcInfo.triggerType;
 
-    // Handle trace-context.
-    // XXX bring back distributed tracing language.
-    // XXX also with v4 we don't ahve access to the request headers (context.req.headers),
-    //     so we cannot optionally use a traceparent header there. That means
-    //     distributed traces going through HTTP-triggered Azure Functions
-    //     won't be connected in our waterfall because of the broken trace limitation.
-    // XXX Possible concerns:
-    // - Was `traceContext` appropriate/accurate with Azure Functions v3?
-    //   I.e. for TRIGGER_HTTP, did it reflect an incoming traceparent header?
-    // - When incoming requests do *not* provide trace context, Azure Functions
-    //   provides a traceparent. At least when running locally it always has
-    //   the sampling flag set *false*! If this happens in a deployed function
-    //   then that looks like no tracing at all. Do we want to call out
-    //   `traceContinuationStrategy`?
-    // Trace-context.
-
     // `InvocationContext.traceContext` is broken: it results in sampled=false
     // (i.e. traces are discarded) and/or broken traces because it creates an
     // internal Span ID in the trace that cannot be ingested.