DynamoDB: prerequisite and JavaScript SDK v2 and v3 – 1

by Renzo Mischianti · Published 12 April 2021 · Updated 11 February 2024

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DynamoDB prerequisite and JavaScript SDK v2 and v3 introduction

I want to write a step by step tutorial on how to create an Alexa Smart Home Skill from scratch. So I’m going to present all the prerequisites and steps to create a Smart Home Skill connected to our micro-controller able to manage every connected device.

I’m going to start with a simple argument like the database DynamoDB next we are going to create a Smart Skill and connect to a messaging server the microcontroller and then put all together.

In this schema you can check witch part we are going to analyze (selected in yellow).

Every lambdas (see lambda like a REST call for now) when called, they may need to save some data, and now we are going to see this part.

Now let’s get started with our DynamoDB.

Amazon DynamoDB is a key-value and document database that delivers single-digit millisecond performance at any scale. It’s a fully managed, multi-region, multi-active, durable database with built-in security, backup and restore, and in-memory caching for internet-scale applications.
Amazon

Prerequisite

You need an AWS console account and a developer account.

Installation of AWS CLI to manage anche check the changes on you DynamoDB.

Install NodeJS to execute script locally.

If you want try to put your DynamoDB locally, Install Docker (or install DynamoDB manually).

Code and resources

First create a folder, for me I create

dynamodb-tutorial-examples-iot

Install Optional Tools

The use of these tools is optional as they are useful, but not required.

Git

Git 2.0 or greater is required only if you want to clone the source code locally. At a command line, you can verify if git is installed by running the command:

git --version

If it is not properly installed or is not a version greater than 2.0, visit https://git-scm.com/downloads to download and install a version for your platform.

Get the Source Code via Git

If you have git installed on your workstation, you can use the following instructions to pull the source code into your working directory.

From the command-line, navigate into the working directory on your desktop: dynamodb-examples
Run the following command to pull the source code to a working directory:

git clone https://github.com/xreef/dynamodb-tutorial-examples-iot.git

Get the Source Code via Download

If you do not have git installed, download and unzip the zipped contents of the sample from

https://github.com/xreef/dynamodb-tutorial-examples-iot/archive/refs/heads/master.zip

into your desktop working directory: dynamodb-tutorial-examples-iot.

Manage the setup file

Rename setup-template.txt in setup.txt.

The file should contain:

[Login with Amazon Client ID]
XXXXX.XXXXXXXXXXX-XXX-XXXXXX.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

[Login with Amazon Client Secret]
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

[AWS Access Key ID]
XXXXXXXXXXXXXXXXXXXX

[AWS Secret Access Key]
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

[Region]
XX-XXXX-X

Create Access key Security Credentials

To grant access from your PC to AWS DynamoDB you must create an Access Key ID and Secret Access Key.

Go to Identity and Access Management (IAM), from the Profile menu (your user login) select My Security Credential;
https://console.aws.amazon.com/iam/home#/security_credentials
Click on Access keys (access key ID and secret access key) accordion;
And click on Create New Access Key button.
Copy Access Key ID and Secret Access Key to setup file in the relative section

[Access Key ID]
XXXXXXXXXXXXXXXXXXXX

[AWS Secret Access Key]
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Configure credential to execute locally DynamoDB script

Now from the command prompt launch aws configure command;

$ aws configure
AWS Access Key ID [None]: XXXXXXXXXXXXXXXXXXXX
AWS Secret Access Key [None]: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Default region name [None]: eu-west-1
Default output format [None]: json

Insert your [AWS Access Key ID] then [AWS Secret Access Key] get from file setup.txt;
Insert your region (It’s better if you select a region good for your country);
Now insert an output format (json for me).

Now you are connected to your AWS account, and you can directly launch the scripts to query the database.

Script (JavaScript) V2 and V3

You can use DynamoDB with 2 versions of the library. These libraries allow you to work easily with Amazon Web Services, when I write this article version 2 is the most used, bue v3 is a rewrite of v2 with some new features like a modular architecture with a separate package for each service. It also includes many frequently requested features, such as a first-class TypeScript support and a new middleware stack.

I’d like to show you v2 and v3 code, and you are going to select the version that you prefer.

Initializing environment

Now we must initialize the environment to use the scripts.

Install NodeJS (and npm if needed).
Go to folder dynamodb-tutorial-examples-iot\dynamodb-examples\jsv2 for v2 scripts and dynamodb-tutorial-examples-iot\dynamodb-examples\jsv3 for v3 scripts.
Launch npm i.
In all js scripts change the region in according to your setting (and DB position if needed) put selected region in setup.txt file.

[Region]
XX-XXXX-X

You are going to find the region on v2 scripts in AWS.config.update section:

AWS.config.update({
    apiVersion: '2012-08-10',
    region: "eu-west-1",
    // endpoint: "http://localhost:8000",
    // // accessKeyId default can be used while using the downloadable version of DynamoDB.
    // // For security reasons, do not store AWS Credentials in your files. Use Amazon Cognito instead.
    // accessKeyId: "9oiaf7",
    // // secretAccessKey default can be used while using the downloadable version of DynamoDB.
    // // For security reasons, do not store AWS Credentials in your files. Use Amazon Cognito instead.
    // secretAccessKey: "yz5i9"
});

For v3 scripts you are going to find It in a const object.

const configDynamoDB = {
    version: 'latest',
    region: "eu-west-1",
    // endpoint: "http://localhost:8000",
    // credentials: {
    //     // accessKeyId default can be used while using the downloadable version of DynamoDB.
    //     // For security reasons, do not store AWS Credentials in your files. Use Amazon Cognito instead.
    //     accessKeyId: "9oiaf7",
    //     // secretAccessKey default can be used while using the downloadable version of DynamoDB.
    //     // For security reasons, do not store AWS Credentials in your files. Use Amazon Cognito instead.
    //     secretAccessKey: "yz5i9"
    // }
};

Now we are ready to launch the scripts.

JS packages difference

The big difference from v2 and v3 is that v2 have a single package imported

    "aws-sdk": "^2.802.0"

v3 have modular packages, so we can go to import only what we need, and in this case import the DynamoDB client.

    "@aws-sdk/client-dynamodb": "^1.0.0-rc.7"

Thanks

This was the basic introduction to the work environment, in the next article we will start over from here to start running the code.

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