feat: use dynamically determined latest Node.js runtime for Lambda handlers instead (#641)

`NODEJS_LATEST` still points to Node.js 18, which is already EOL.

Related upstream issue: aws/aws-cdk#28125

---

_By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license_

Author: Eugene Cheung

lib/dashboard/widget/BitmapWidget.ts

@@ -3,7 +3,12 @@ import * as path from "path";
 import { Duration, Tags } from "aws-cdk-lib";
 import { IWidget } from "aws-cdk-lib/aws-cloudwatch";
 import { Effect, PolicyStatement } from "aws-cdk-lib/aws-iam";
-import { Code, Function, IFunction, Runtime } from "aws-cdk-lib/aws-lambda";
+import {
+  Code,
+  determineLatestNodeRuntime,
+  Function,
+  IFunction,
+} from "aws-cdk-lib/aws-lambda";
 import { RetentionDays } from "aws-cdk-lib/aws-logs";
 import { Construct } from "constructs";
 
@@ -34,7 +39,7 @@ export class BitmapWidgetRenderingSupport extends Construct {
         "Custom Widget Render for Bitmap Widgets (cdk-monitoring-constructs)",
       handler: "index.handler",
       memorySize: 128,
-      runtime: Runtime.NODEJS_LATEST,
+      runtime: determineLatestNodeRuntime(this),
       timeout: Duration.seconds(60),
       logRetention: RetentionDays.ONE_DAY,
     });

lib/monitoring/aws-secretsmanager/SecretsManagerMetricsPublisher.ts

@@ -4,7 +4,12 @@ import { Duration, Names } from "aws-cdk-lib";
 import { Rule, RuleTargetInput, Schedule } from "aws-cdk-lib/aws-events";
 import { LambdaFunction } from "aws-cdk-lib/aws-events-targets";
 import { Effect, PolicyStatement } from "aws-cdk-lib/aws-iam";
-import { Code, Function, IFunction, Runtime } from "aws-cdk-lib/aws-lambda";
+import {
+  Code,
+  determineLatestNodeRuntime,
+  Function,
+  IFunction,
+} from "aws-cdk-lib/aws-lambda";
 import { RetentionDays } from "aws-cdk-lib/aws-logs";
 import { ISecret } from "aws-cdk-lib/aws-secretsmanager";
 import { Construct } from "constructs";
@@ -34,7 +39,7 @@ export class SecretsManagerMetricsPublisher extends Construct {
         "Custom metrics publisher for SecretsManager Secrets (cdk-monitoring-constructs)",
       handler: "index.handler",
       memorySize: 128,
-      runtime: Runtime.NODEJS_LATEST,
+      runtime: determineLatestNodeRuntime(this),
       timeout: Duration.seconds(60),
       logRetention: RetentionDays.ONE_DAY,
     });

test/common/alarm/action/LambdaAlarmActionStrategy.test.ts

@@ -1,15 +1,19 @@
 import { Stack } from "aws-cdk-lib";
 import { Template } from "aws-cdk-lib/assertions";
 import { Alarm, Metric } from "aws-cdk-lib/aws-cloudwatch";
-import { Function, InlineCode, Runtime } from "aws-cdk-lib/aws-lambda";
+import {
+  determineLatestNodeRuntime,
+  Function,
+  InlineCode,
+} from "aws-cdk-lib/aws-lambda";
 
 import { LambdaAlarmActionStrategy } from "../../../../lib";
 
 test("snapshot test: Lambda function", () => {
   const stack = new Stack();
   const onAlarmFunction = new Function(stack, "alarmLambda", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -28,7 +32,7 @@ test("snapshot test: Lambda alias", () => {
   const stack = new Stack();
   const onAlarmFunction = new Function(stack, "alarmLambda", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -48,7 +52,7 @@ test("snapshot test: Lambda version", () => {
   const stack = new Stack();
   const onAlarmFunction = new Function(stack, "alarmLambda", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });

test/common/alarm/action/__snapshots__/LambdaAlarmActionStrategy.test.ts.snap

@@ -1,14 +1,17 @@
 import { Stack } from "aws-cdk-lib";
-import { Code, Function, Runtime } from "aws-cdk-lib/aws-lambda";
+import {
+  Code,
+  determineLatestNodeRuntime,
+  Function,
+} from "aws-cdk-lib/aws-lambda";
 
 import { CustomWidget } from "../../../lib/dashboard/widget/CustomWidget";
 
 test("widget", () => {
   const stack = new Stack();
 
   const handler = new Function(stack, "Function", {
-    // execution environment
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     // code loaded from "lambda" directory
     code: Code.fromInline(
       'exports.handler = function(event, ctx, cb) { return cb(null, "Hello World!"); }',

test/dashboard/widget/CustomWidget.test.ts

@@ -2,10 +2,10 @@ import { Duration, Stack } from "aws-cdk-lib";
 import { Template } from "aws-cdk-lib/assertions";
 import { Color, ComparisonOperator } from "aws-cdk-lib/aws-cloudwatch";
 import {
+  determineLatestNodeRuntime,
   Function,
   InlineCode,
   LayerVersion,
-  Runtime,
 } from "aws-cdk-lib/aws-lambda";
 
 import { AlarmWithAnnotation, LambdaFunctionMonitoring } from "../../../lib";
@@ -19,7 +19,7 @@ test("snapshot test: default iterator and no alarms", () => {
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -49,7 +49,7 @@ test("snapshot test: non-iterator and no alarms", () => {
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -72,7 +72,7 @@ test("snapshot test: all alarms", () => {
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -190,7 +190,7 @@ test("snapshot test: all alarms", () => {
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
     layers: [
@@ -230,7 +230,7 @@ test("snapshot test: all alarms, alarmPrefix on error dedupeString", () => {
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -376,7 +376,7 @@ test("snapshot test: all alarms, alarmPrefix on latency dedupeString", () => {
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -519,7 +519,7 @@ test("throws error if attempting to create iterator age alarm if not an iterator
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -549,7 +549,7 @@ test("throws error if attempting to create offsetLag alarm if not an offsetLag L
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -578,7 +578,7 @@ test("doesn't create alarms for enhanced Lambda Insights metrics if not enabled"
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_LATEST,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
   });
@@ -689,7 +689,7 @@ test("snapshot test: latency alarms with percentage of timeout with specific tim
 
   const lambdaFunction = new Function(stack, "Function", {
     functionName: "DummyLambda",
-    runtime: Runtime.NODEJS_18_X,
+    runtime: determineLatestNodeRuntime(stack),
     code: InlineCode.fromInline("{}"),
     handler: "Dummy::handler",
     timeout: Duration.seconds(100),