SNS

Full SNS Setup on AWS — Short & Clear

Step 1 — Create SNS Topic

1. AWS Console → SNS → Topics
2. Click Create topic
3. Type: Standard
4. Name: order-processer-notification-nishan
5. Click Create topic
6. Copy the Topic ARN shown on the next page

Step 2 — Create Subscription (Use SMS to avoid Gmail issues)

1. Click your topic name
2. Click Create subscription
3. Fill in:

4. Click Create subscription
5. ✅ No email confirmation needed — active immediately

Step 3 — Give Lambda Permission

1. IAM → Roles
2. Find your processor Lambda role
3. Add permissions → Attach policies
4. Search and attach AmazonSNSFullAccess
5. Click Add permissions

Step 4 — Add SNS Code to Processor Lambda

1. Lambda → processor function
2. Paste this code and click Deploy

import { DynamoDBClient, PutItemCommand } from "@aws-sdk/client-dynamodb";
import { S3Client, PutObjectCommand } from "@aws-sdk/client-s3";
import { SNSClient, PublishCommand } from "@aws-sdk/client-sns";

const dynamoClient = new DynamoDBClient({});
const s3Client = new S3Client({});
const snsClient = new SNSClient({});

const SNS_TOPIC_ARN = "arn:aws:sns:us-east-1:237795118651:order-processer-notification-nishan";
const OUTPUT_BUCKET = "order-process-nishan";

export const handler = async (event) => {
    try {
        for (const record of event.Records) {
            const messageBody = JSON.parse(record.body);
            const orderId = messageBody.orderId;

            if (!orderId) {
                console.error("Missing orderId");
                continue;
            }

            // STEP 1: Save to DynamoDB
            await dynamoClient.send(new PutItemCommand({
                TableName: "ordernishan",
                Item: {
                    orderId:   { S: orderId },
                    customer:  { S: messageBody.customer || "UNKNOWN" },
                    amount:    { N: String(messageBody.amount || 0) },
                    status:    { S: "PROCESSED" },
                    createdAt: { S: new Date().toISOString() }
                }
            }));
            console.log(`✅ Saved to DynamoDB: ${orderId}`);

            // STEP 2: Save to S3
            await s3Client.send(new PutObjectCommand({
                Bucket:      OUTPUT_BUCKET,
                Key:         `processed/${orderId}.json`,
                Body:        JSON.stringify({ orderId, ...messageBody, status: "PROCESSED" }),
                ContentType: "application/json"
            }));
            console.log(`✅ Saved to S3: ${orderId}`);

            // STEP 3: Send SNS Notification
            await snsClient.send(new PublishCommand({
                TopicArn: SNS_TOPIC_ARN,
                Message:  `Order ${orderId} processed! Customer: ${messageBody.customer}, Amount: $${messageBody.amount}`
            }));
            console.log(`✅ SNS sent for: ${orderId}`);
        }

        return { statusCode: 200 };

    } catch (error) {
        console.error("❌ Error:", error);
        throw error;
    }
};

Step 5 — Test It

1. Upload a file to your source S3 bucket
2. Watch the flow trigger automatically
3. Check CloudWatch logs for ✅ messages
4. You should receive an SMS on your phone ✅

Full Flow Summary

S3 (upload) → receiver Lambda → SQS → processor Lambda
                                         ├── DynamoDB ✅
                                         ├── S3 output ✅
                                         └── SNS (SMS) ✅

That's it! 🚀