Fixed tracing examples

Author: dreamorosi

examples/cdk/lib/example-stack.MyFunction.ts

@@ -1,9 +1,7 @@
-import {Metrics, MetricUnits} from '@aws-lambda-powertools/metrics';
-import {Logger} from '@aws-lambda-powertools/logger';
-import {Tracer} from '@aws-lambda-powertools/tracer';
-import { Subsegment } from 'aws-xray-sdk-core';
-
-
+import { Context } from 'aws-lambda';
+import { Metrics, MetricUnits } from '@aws-lambda-powertools/metrics';
+import { Logger } from '@aws-lambda-powertools/logger';
+import { Tracer } from '@aws-lambda-powertools/tracer';
 
 const namespace = 'CDKExample';
 const serviceName = 'MyFunctionWithStandardHandler';
@@ -12,7 +10,14 @@ const metrics = new Metrics({ namespace: namespace, service: serviceName });
 const logger = new Logger({ logLevel: 'INFO', serviceName: serviceName });
 const tracer = new Tracer({ serviceName: serviceName });
 
-export const handler = async (event: any, context: any) => {
+export const handler = async (_event: unknown, context: Context): Promise<unknown> => {
+  // Since we are in manual mode we need to create the handler segment (the 4 lines below would be done for you by decorator/middleware)
+  // we do it at the beginning because we want to trace the whole duration of the handler
+  const segment = tracer.getSegment(); // This is the facade segment (the one that is created by Lambda & that can't be manipulated)
+  const handlerSegment = segment.addNewSubsegment(`## ${context.functionName}`);
+  // TODO: expose tracer.annotateColdStart()
+  tracer.putAnnotation('ColdStart', Tracer.coldStart);
+
   // ### Experiment logger
   logger.addPersistentLogAttributes({
     testKey: 'testValue',
@@ -36,13 +41,11 @@ export const handler = async (event: any, context: any) => {
   metrics.raiseOnEmptyMetrics();
 
   // ### Experiment tracer
+
   tracer.putAnnotation('Myannotation', 'My annotation\'s value');
 
   // Create subsegment & set it as active
-  const subsegment = new Subsegment('MySubSegment');
-  tracer.setSegment(subsegment);
-  // TODO: Add the ColdStart annotation !!! NOT POSSIBLE
-  // tracer.putAnnotation('ColdStart', tracer);
+  const subsegment = handlerSegment.addNewSubsegment('MySubSegment');
 
   try {
     throw new Error('test');
@@ -54,4 +57,5 @@ export const handler = async (event: any, context: any) => {
 
   // Close subsegment
   subsegment.close();
+  handlerSegment.close();
 };

examples/cdk/lib/example-stack.MyFunctionWithDecorator.ts

@@ -1,8 +1,7 @@
-import { Metrics, MetricUnits } from '@aws-lambda-powertools/metrics';
-import { Logger, createLogger } from '@aws-lambda-powertools/logger';
 import { Tracer } from '@aws-lambda-powertools/tracer';
-import { Subsegment } from 'aws-xray-sdk-core';
 import { Callback, Context } from 'aws-lambda';
+import { Metrics, MetricUnits } from '@aws-lambda-powertools/metrics';
+import { Logger } from '@aws-lambda-powertools/logger';
 
 const namespace = 'CDKExample';
 const serviceName = 'MyFunctionWithDecorator';
@@ -19,7 +18,7 @@ export class MyFunctionWithDecorator {
     raiseOnEmptyMetrics: true,
     defaultDimensions: { environment: 'example', type: 'withDecorator' },
   })
-  public handler(_event: any, _context: Context, _callback: Callback<any>): void | Promise<any> {
+  public handler(_event: unknown, _context: Context, _callback: Callback<unknown>): void | Promise<unknown> {
     // ### Experiment logger
     logger.addPersistentLogAttributes({
       testKey: 'testValue',
@@ -40,7 +39,9 @@ export class MyFunctionWithDecorator {
     tracer.putAnnotation('Myannotation', 'My annotation\'s value');
 
     // Create subsegment & set it as active
-    const subsegment = new Subsegment('MySubSegment');
+    const segment = tracer.getSegment(); // This is the facade segment (the one that is created by Lambda & that can't be manipulated)
+    const subsegment = segment.addNewSubsegment('MySubSegment');
+
     tracer.setSegment(subsegment);
     // TODO: Add the ColdStart annotation !!! NOT POSSIBLE
     // tracer.putAnnotation('ColdStart', tracer);

examples/cdk/lib/example-stack.MyFunctionWithMiddy.ts

@@ -1,39 +1,43 @@
 import middy from '@middy/core'
-import {Metrics, MetricUnits} from '@aws-lambda-powertools/metrics';
 import { Callback, Context } from 'aws-lambda';
+import { Metrics, MetricUnits } from '@aws-lambda-powertools/metrics';
 
+const metrics = new Metrics({ namespace: 'CDKExample', service: 'withMiddy' }); // Sets metric namespace, and service as a metric dimension
 
-const metrics = new Metrics({namespace:"CDKExample", service:"withMiddy"}); // Sets metric namespace, and service as a metric dimension
+type CustomEvent = {
+  throw: boolean
+};
 
 class MyFunctionWithDecorator {
 
-  @metrics.logMetrics({captureColdStartMetric: true})
-  public handler(_event: any, _context: Context, _callback: Callback<any>): void | Promise<any> {
+  @metrics.logMetrics({ captureColdStartMetric: true })
+  public handler(_event: CustomEvent, _context: Context, _callback: Callback<unknown>): void | Promise<unknown> {
     metrics.addMetric('test-metric', MetricUnits.Count, 10);
-    if(_event.throw) {
+    if (_event.throw) {
       throw new Error('Test error');
     }
   }
 }
 
 const handler = middy(async (_event, _context) => {
 
-  const handlerClass = new MyFunctionWithDecorator()
-  return handlerClass.handler(_event, _context, () => {});
-})
+  const handlerClass = new MyFunctionWithDecorator();
+
+  return handlerClass.handler(_event, _context, () => console.log('Lambda invoked!'));
+});
 
 handler.before(async (_request) => {
   metrics.addMetric('beforeHandlerCalled', MetricUnits.Count, 1);
-})
+});
 
 handler.after(async (_request) => {
   // Won't be flushed since happens after 
   metrics.addMetric('afterHandlerCalled', MetricUnits.Count, 1);
 
-})
+});
 
 handler.onError(async (_request) => {
   metrics.addMetric('onErrorHandlerCalled', MetricUnits.Count, 1);
-})
+});
 
-module.exports = { handler }
+module.exports = { handler };

examples/cdk/lib/example-stack.ts

@@ -1,5 +1,5 @@
 import { Stack, StackProps, custom_resources, aws_iam } from 'aws-cdk-lib';
-import {Events} from '@aws-lambda-powertools/commons';
+import { Events } from '@aws-lambda-powertools/commons';
 import { Construct } from 'constructs';
 import * as lambda from 'aws-cdk-lib/aws-lambda-nodejs';
 import { Tracing } from 'aws-cdk-lib/aws-lambda';