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In this article, we will explore how to build a serverless chat room using AWS Lambda, API Gateway, Websockets, DynamoDB, and Terraform. This project is a great example of how to leverage serverless architecture for real-time applications. Below, you’ll find the steps, commands, and code snippets to deploy and manage this project.
You Should Know:
1. Prerequisites
- AWS Account with necessary permissions.
- Terraform installed on your local machine.
- Basic knowledge of AWS services (Lambda, API Gateway, DynamoDB).
- Go programming language installed (for Lambda functions).
2. Terraform Configuration
Terraform will be used to manage the infrastructure as code. Below is a sample `main.tf` file to set up the required AWS resources:
[hcl]
provider “aws” {
region = “us-east-1”
}
resource “aws_dynamodb_table” “chat_table” {
name = “ChatMessages”
billing_mode = “PAY_PER_REQUEST”
hash_key = “MessageID”
attribute {
name = “MessageID”
type = “S”
}
}
resource “aws_lambda_function” “chat_lambda” {
function_name = “ChatRoomLambda”
handler = “main”
runtime = “go1.x”
role = aws_iam_role.lambda_exec_role.arn
filename = “lambda_function.zip”
source_code_hash = filebase64sha256(“lambda_function.zip”)
}
resource “aws_apigatewayv2_api” “websocket_api” {
name = “ChatRoomWebSocket”
protocol_type = “WEBSOCKET”
route_selection_expression = “$request.body.action”
}
resource “aws_apigatewayv2_stage” “default_stage” {
api_id = aws_apigatewayv2_api.websocket_api.id
name = “production”
auto_deploy = true
}
[/hcl]
3. Deploying the Infrastructure
Run the following Terraform commands to deploy the infrastructure:
terraform init terraform plan terraform apply
4. Lambda Function Code
Here’s a simple Go-based Lambda function to handle WebSocket connections and store messages in DynamoDB:
[go]
package main
import (
“context”
“fmt”
“github.com/aws/aws-lambda-go/events”
“github.com/aws/aws-lambda-go/lambda”
“github.com/aws/aws-sdk-go/aws”
“github.com/aws/aws-sdk-go/service/dynamodb”
)
func handler(ctx context.Context, request events.APIGatewayWebsocketProxyRequest) (events.APIGatewayProxyResponse, error) {
svc := dynamodb.New(session.New())
input := &dynamodb.PutItemInput{
TableName: aws.String(“ChatMessages”),
Item: map[string]*dynamodb.AttributeValue{
“MessageID”: {
S: aws.String(request.RequestContext.ConnectionID),
},
“Message”: {
S: aws.String(request.Body),
},
},
}
_, err := svc.PutItem(input)
if err != nil {
return events.APIGatewayProxyResponse{StatusCode: 500}, err
}
return events.APIGatewayProxyResponse{StatusCode: 200}, nil
}
func main() {
lambda.Start(handler)
}
[/go]
5. Testing the Chat Room
- Use a WebSocket client (e.g.,
wscat) to connect to the API Gateway WebSocket URL. - Send messages and verify they are stored in DynamoDB.
What Undercode Say:
This project demonstrates the power of serverless architecture for building scalable, real-time applications. By combining AWS Lambda, API Gateway, and DynamoDB, you can create a fully managed chat room without worrying about server maintenance. Terraform simplifies the deployment and management of these resources, making it easier to iterate and improve the application.
Additional Commands and Tips:
–
References:
Reported By: Darryl Ruggles – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
