docs: recommend lambda runtime nodejs12.x (#12807)

Follow-up to #12713
This PR recommends NODEJS_12_X instead of NODEJS_10_X in aws-cdk READMEs.

Reasons for recommending NODEJS_12_X:
* Node.js 10.x is going end-of-life on April 30th, 2021
* Node.js 12.x went LTS in October 2019, and has been actively supported till October 2020.
* Node.js 14.x went LTS in October 2020, and is now actively supported LTS version.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: trivikr

packages/@aws-cdk/aws-apigateway/README.md

@@ -163,7 +163,7 @@ The following example shows how to use an API Key with a usage plan:
 
 ```ts
 const hello = new lambda.Function(this, 'hello', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'hello.handler',
   code: lambda.Code.fromAsset('lambda')
 });
@@ -230,7 +230,7 @@ The following example shows how to use a rate limited api key :
 
 ```ts
 const hello = new lambda.Function(this, 'hello', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'hello.handler',
   code: lambda.Code.fromAsset('lambda')
 });
@@ -260,7 +260,7 @@ have to define your models and mappings for the request, response, and integrati
 
 ```ts
 const hello = new lambda.Function(this, 'hello', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'hello.handler',
   code: lambda.Code.fromAsset('lambda')
 });

packages/@aws-cdk/aws-cloudfront/README.md

@@ -282,7 +282,7 @@ The following shows a Lambda@Edge function added to the default behavior and tri
 
 ```ts
 const myFunc = new cloudfront.experimental.EdgeFunction(this, 'MyFunction', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler')),
 });
@@ -310,7 +310,7 @@ If the stack is in `us-east-1`, a "normal" `lambda.Function` can be used instead
 
 ```ts
 const myFunc = new lambda.Function(this, 'MyFunction', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler')),
 });
@@ -321,14 +321,14 @@ you can also set a specific stack ID for each Lambda@Edge.
 
 ```ts
 const myFunc1 = new cloudfront.experimental.EdgeFunction(this, 'MyFunction1', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler1')),
   stackId: 'edge-lambda-stack-id-1'
 });
 
 const myFunc2 = new cloudfront.experimental.EdgeFunction(this, 'MyFunction2', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler2')),
   stackId: 'edge-lambda-stack-id-2'

packages/@aws-cdk/aws-cloudtrail/README.md

@@ -175,7 +175,7 @@ configures logging of Lambda data events for a specific Function.
 ```ts
 const trail = new cloudtrail.Trail(this, 'MyAmazingCloudTrail');
 const amazingFunction = new lambda.Function(stack, 'AnAmazingFunction', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: "hello.handler",
   code: lambda.Code.fromAsset("lambda"),
 });

packages/@aws-cdk/aws-codepipeline-actions/README.md

@@ -629,7 +629,7 @@ const lambdaCode = lambda.Code.fromCfnParameters();
 const func = new lambda.Function(lambdaStack, 'Lambda', {
   code: lambdaCode,
   handler: 'index.handler',
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
 });
 // used to make sure each CDK synthesis produces a different Version
 const version = func.addVersion('NewVersion');
@@ -921,7 +921,7 @@ import * as lambda from '@aws-cdk/aws-lambda';
 const lambdaInvokeAction = new codepipeline_actions.LambdaInvokeAction({
   actionName: 'Lambda',
   lambda: new lambda.Function(this, 'Func', {
-    runtime: lambda.Runtime.NODEJS_10_X,
+    runtime: lambda.Runtime.NODEJS_12_X,
     handler: 'index.handler',
     code: lambda.Code.fromInline(`
         const AWS = require('aws-sdk');

packages/@aws-cdk/aws-cognito/README.md

@@ -343,7 +343,7 @@ on the construct, as so -
 
 ```ts
 const authChallengeFn = new lambda.Function(this, 'authChallengeFn', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromInline('auth challenge'),
 });
@@ -357,7 +357,7 @@ const userpool = new cognito.UserPool(this, 'myuserpool', {
 });
 
 userpool.addTrigger(cognito.UserPoolOperation.USER_MIGRATION, new lambda.Function(this, 'userMigrationFn', {
-    runtime: lambda.Runtime.NODEJS_10_X,
+    runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromInline('user migration'),
 }));

packages/@aws-cdk/aws-config/README.md

@@ -237,7 +237,7 @@ import * as targets from '@aws-cdk/aws-events-targets';
 const evalComplianceFn = new lambda.Function(this, 'CustomFunction', {
   code: lambda.AssetCode.fromInline('exports.handler = (event) => console.log(event);'),
   handler: 'index.handler',
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
 });
 
 // A custom rule that runs on configuration changes of EC2 instances

packages/@aws-cdk/aws-lambda/README.md

@@ -18,7 +18,7 @@ import * as lambda from '@aws-cdk/aws-lambda';
 import * as path from 'path';
 
 const fn = new lambda.Function(this, 'MyFunction', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler')),
 });
@@ -88,7 +88,7 @@ function. To reference the autogenerated Role:
 
 ```ts
 const fn = new lambda.Function(this, 'MyFunction', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler')),
 
@@ -101,7 +101,7 @@ it appropriate permissions:
 
 ```ts
 const fn = new lambda.Function(this, 'MyFunction', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler')),
   role: myRole // user-provided role
@@ -251,7 +251,7 @@ setting the `deadLetterQueueEnabled: true` configuration.
 import * as lambda from '@aws-cdk/aws-lambda';
 
 const fn = new lambda.Function(this, 'MyFunction', {
-    runtime: lambda.Runtime.NODEJS_10_X,
+    runtime: lambda.Runtime.NODEJS_12_X,
     handler: 'index.handler',
     code: lambda.Code.fromInline('exports.handler = function(event, ctx, cb) { return cb(null, "hi"); }'),
     deadLetterQueueEnabled: true
@@ -266,7 +266,7 @@ import * as sqs from '@aws-cdk/aws-sqs';
 
 const dlq = new sqs.Queue(this, 'DLQ');
 const fn = new lambda.Function(this, 'MyFunction', {
-    runtime: lambda.Runtime.NODEJS_10_X,
+    runtime: lambda.Runtime.NODEJS_12_X,
     handler: 'index.handler',
     code: lambda.Code.fromInline('exports.handler = function(event, ctx, cb) { return cb(null, "hi"); }'),
     deadLetterQueue: dlq
@@ -282,7 +282,7 @@ to learn more about AWS Lambdas and DLQs.
 import * as lambda from '@aws-cdk/aws-lambda';
 
 const fn = new lambda.Function(this, 'MyFunction', {
-    runtime: lambda.Runtime.NODEJS_10_X,
+    runtime: lambda.Runtime.NODEJS_12_X,
     handler: 'index.handler',
     code: lambda.Code.fromInline('exports.handler = function(event, ctx, cb) { return cb(null, "hi"); }'),
     tracing: lambda.Tracing.ACTIVE
@@ -321,7 +321,7 @@ to learn more about AWS Lambda's Profiling support.
 import * as lambda from '@aws-cdk/aws-lambda';
 
 const fn = new lambda.Function(this, 'MyFunction', {
-    runtime: lambda.Runtime.NODEJS_10_X,
+    runtime: lambda.Runtime.NODEJS_12_X,
     handler: 'index.handler',
     code: lambda.Code.fromInline('exports.handler = function(event, ctx, cb) { return cb(null, "hi"); }'),
     reservedConcurrentExecutions: 100

packages/@aws-cdk/aws-rds/README.md

@@ -525,7 +525,7 @@ const cluster = new rds.ServerlessCluster(this, 'AnotherCluster', {
 });
 
 const fn = new lambda.Function(this, 'MyFunction', {
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   handler: 'index.handler',
   code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler')),
   environment: {

packages/@aws-cdk/aws-sns-subscriptions/README.md

@@ -78,7 +78,7 @@ import * as subscriptions from '@aws-cdk/aws-sns-subscriptions';
 
 const myFunction = new lambda.Function(this, 'Echo', {
   handler: 'index.handler',
-  runtime: lambda.Runtime.NODEJS_10_X,
+  runtime: lambda.Runtime.NODEJS_12_X,
   code: lambda.Code.fromInline(`exports.handler = ${handler.toString()}`)
 });
 

packages/@aws-cdk/aws-stepfunctions-tasks/README.md

@@ -189,7 +189,7 @@ const convertToSeconds = new tasks.EvaluateExpression(this, 'Convert to seconds'
 const createMessage = new tasks.EvaluateExpression(this, 'Create message', {
   // Note: this is a string inside a string.
     expression: '`Now waiting ${$.waitSeconds} seconds...`',
-    runtime: lambda.Runtime.NODEJS_10_X,
+    runtime: lambda.Runtime.NODEJS_12_X,
   resultPath: '$.message',
 });
 
@@ -213,7 +213,7 @@ new sfn.StateMachine(this, 'StateMachine', {
 
 The `EvaluateExpression` supports a `runtime` prop to specify the Lambda
 runtime to use to evaluate the expression. Currently, the only runtime
-supported is `lambda.Runtime.NODEJS_10_X`.
+supported is `lambda.Runtime.NODEJS_12_X`.
 
 
 ## Athena

packages/aws-cdk/README.md

@@ -207,7 +207,7 @@ Usage of output in a CDK stack
 const fn = new lambda.Function(this, "fn", {
   handler: "index.handler",
   code: lambda.Code.fromInline(`exports.handler = \${handler.toString()}`),
-  runtime: lambda.Runtime.NODEJS_10_X
+  runtime: lambda.Runtime.NODEJS_12_X
 });
 
 new cdk.CfnOutput(this, 'FunctionArn', {