Amazon web services – How to create a dynamo db table and create item entries in the same dynamo db table using cloud formation template?

Here is a small example that creates a table and adds 5 items:

AWSTemplateFormatVersion: '2010-09-09'
Resources:
  MyDynamoDBTable:
    Type: 'AWS::DynamoDB::Table'
    Properties:
      BillingMode: PAY_PER_REQUEST
      AttributeDefinitions:
        - AttributeName: pk
          AttributeType: S
        - AttributeName: sk
          AttributeType: S
      KeySchema:
        - AttributeName: pk
          KeyType: HASH
        - AttributeName: sk
          KeyType: RANGE
  MyCustomResourceLambdaFunction:
    Type: 'AWS::Lambda::Function'
    Properties:
      Runtime: nodejs14.x
      Handler: index.handler
      Role: !GetAtt MyLambdaExecutionRole.Arn
      Environment:
        Variables:
          tableName: !Ref MyDynamoDBTable
      Code:
        ZipFile: |
          const AWS = require('aws-sdk');
          const client = new AWS.DynamoDB();
          const dynamodb = new AWS.DynamoDB.DocumentClient();
          const response = require('cfn-response');
          
          exports.handler = async (event, context) => {
            try {
              const tableName = process.env.tableName
              console.log(tableName)
              var params = {
                'TableName': tableName
              };
            
              client.waitFor('tableExists', params, function(err, data) {
                if (err) console.log(err, err.stack); // an error occurred
                else     console.log(data);           // successful response
              });

              const itemsToAdd = [
                { pk: 'item1', sk: 'sortKey1', otherAttribute: 'value1' },
                { pk: 'item2', sk: 'sortKey2', otherAttribute: 'value2' },
                { pk: 'item3', sk: 'sortKey3', otherAttribute: 'value3' },
                { pk: 'item4', sk: 'sortKey4', otherAttribute: 'value4' },
                { pk: 'item5', sk: 'sortKey5', otherAttribute: 'value5' },
              ];
              
              const putItemPromises = itemsToAdd.map((item) => {
                const params = {
                  TableName: tableName,
                  Item: item,
                };
                return dynamodb.put(params).promise();
              });
              
              await Promise.all(putItemPromises).then(res=>console.log(res)).catch(err=>console.log(err))
              
              const responseData = { Result: 'Items added successfully' };
              response.send(event, context, response.SUCCESS, responseData);
            } catch (error) {
              console.log(error)
              const responseData = { Error: 'Something went wrong' };
              response.send(event, context, response.FAILED, responseData);
            }
          };
      Timeout: 30
  MyLambdaExecutionRole:
    Type: 'AWS::IAM::Role'
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service: lambda.amazonaws.com
            Action: 'sts:AssumeRole'
      ManagedPolicyArns:
        - 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole'
        - 'arn:aws:iam::aws:policy/AmazonDynamoDBFullAccess'
  MyCustomResource:
    Type: 'Custom::MyCustomResource'
    Properties:
      ServiceToken: !GetAtt MyCustomResourceLambdaFunction.Arn