feat(task-8): Integration with RDS

README.md

@@ -6,6 +6,23 @@
 npm install
 ```
 
+## Environment variables
+
+Copy `env.example` to `.env` and set values for your environment.
+
+For DB-backed cart functionality, these variables are required:
+
+- `DB_HOST`
+- `DB_PORT`
+- `DB_USER`
+- `DB_PASSWORD`
+- `DB_NAME`
+- `DB_SSL`
+- `DB_SYNC`
+- `PRODUCT_SERVICE_URL`
+
+For AWS Lambda deployment, the app exposes serverless handler in `src/lambda.ts`.
+
 
 
 ## Running the app

env.example

@@ -1,4 +1,13 @@
 APP_PORT=4000
+PRODUCT_SERVICE_URL=http://localhost:3000
+
+DB_HOST=localhost
+DB_PORT=5432
+DB_USER=postgres
+DB_PASSWORD=postgres
+DB_NAME=cart_db
+DB_SSL=false
+DB_SYNC=true
 
 ### These variables are needed to make script for getting access_token works 
 AUTH_USERNAME=yourGithubLogin ### It should be your github username

infra/.gitignore

@@ -0,0 +1,5 @@
+node_modules/
+dist/
+cdk.out/
+*.js.map
+*.d.ts

infra/bin/cart-service-infra.ts

@@ -0,0 +1,13 @@
+#!/usr/bin/env node
+import 'source-map-support/register';
+import * as cdk from 'aws-cdk-lib';
+import { CartServiceInfraStack } from '../lib/cart-service-infra-stack';
+
+const app = new cdk.App();
+
+new CartServiceInfraStack(app, 'CartServiceInfraStack', {
+  env: {
+    account: process.env.CDK_DEFAULT_ACCOUNT,
+    region: process.env.CDK_DEFAULT_REGION,
+  },
+});

infra/cdk.context.json

@@ -0,0 +1,10 @@
+{
+  "availability-zones:account=797715838914:region=us-east-1": [
+    "us-east-1a",
+    "us-east-1b",
+    "us-east-1c",
+    "us-east-1d",
+    "us-east-1e",
+    "us-east-1f"
+  ]
+}

infra/cdk.json

@@ -0,0 +1,3 @@
+{
+  "app": "npx ts-node --prefer-ts-exts bin/cart-service-infra.ts"
+}

infra/lib/cart-service-infra-stack.ts

@@ -0,0 +1,125 @@
+import * as path from 'path';
+import * as cdk from 'aws-cdk-lib';
+import { Construct } from 'constructs';
+import * as ec2 from 'aws-cdk-lib/aws-ec2';
+import * as rds from 'aws-cdk-lib/aws-rds';
+import * as lambda from 'aws-cdk-lib/aws-lambda';
+import * as lambdaNodejs from 'aws-cdk-lib/aws-lambda-nodejs';
+import { aws_apigateway as apigateway } from 'aws-cdk-lib';
+
+export class CartServiceInfraStack extends cdk.Stack {
+  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
+    super(scope, id, props);
+
+    const vpc = new ec2.Vpc(this, 'CartVpc', {
+      maxAzs: 2,
+      natGateways: 1,
+      subnetConfiguration: [
+        {
+          name: 'Public',
+          subnetType: ec2.SubnetType.PUBLIC,
+        },
+        {
+          name: 'Private',
+          subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS,
+        },
+      ],
+    });
+
+    const lambdaSecurityGroup = new ec2.SecurityGroup(this, 'CartLambdaSg', {
+      vpc,
+      allowAllOutbound: true,
+      description: 'Security group for cart Lambda',
+    });
+
+    const dbSecurityGroup = new ec2.SecurityGroup(this, 'CartDbSg', {
+      vpc,
+      allowAllOutbound: true,
+      description: 'Security group for cart Postgres instance',
+    });
+
+    dbSecurityGroup.addIngressRule(
+      lambdaSecurityGroup,
+      ec2.Port.tcp(5432),
+      'Allow Lambda to access Postgres',
+    );
+
+    const database = new rds.DatabaseInstance(this, 'CartPostgres', {
+      vpc,
+      vpcSubnets: { subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS },
+      securityGroups: [dbSecurityGroup],
+      engine: rds.DatabaseInstanceEngine.postgres({
+        version: rds.PostgresEngineVersion.VER_16_3,
+      }),
+      instanceType: ec2.InstanceType.of(ec2.InstanceClass.T3, ec2.InstanceSize.MICRO),
+      allocatedStorage: 20,
+      maxAllocatedStorage: 100,
+      credentials: rds.Credentials.fromGeneratedSecret('cart_user'),
+      databaseName: 'cart_db',
+      publiclyAccessible: false,
+      deletionProtection: false,
+      removalPolicy: cdk.RemovalPolicy.DESTROY,
+      deleteAutomatedBackups: true,
+    });
+
+    const lambdaFunction = new lambdaNodejs.NodejsFunction(this, 'LambdaFunction', {
+      runtime: lambda.Runtime.NODEJS_20_X,
+      entry: path.join(__dirname, '../../src/lambda.ts'),
+      handler: 'handler',
+      timeout: cdk.Duration.seconds(30),
+      memorySize: 1024,
+      vpc,
+      vpcSubnets: { subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS },
+      securityGroups: [lambdaSecurityGroup],
+      environment: {
+        DB_HOST: database.instanceEndpoint.hostname,
+        DB_PORT: database.instanceEndpoint.port.toString(),
+        DB_NAME: 'cart_db',
+        DB_USER: 'cart_user',
+        DB_PASSWORD: database.secret!.secretValueFromJson('password').toString(),
+        DB_SSL: 'false',
+        DB_SYNC: 'true',
+        PRODUCT_SERVICE_URL:
+          this.node.tryGetContext('productServiceUrl') ||
+          'https://YOUR_API_ID.execute-api.ap-south-1.amazonaws.com/prod',
+      },
+      bundling: {
+        externalModules: [
+          'aws-sdk',
+          '@nestjs/microservices',
+          '@nestjs/websockets',
+          'class-transformer',
+          'class-validator',
+        ],
+      },
+    });
+
+    database.secret?.grantRead(lambdaFunction);
+    database.connections.allowDefaultPortFrom(lambdaFunction);
+
+    const api = new apigateway.RestApi(this, 'NestApi', {
+      restApiName: 'Nest Service',
+      description: 'This service serves a Nest.js application.',
+      deployOptions: {
+        stageName: 'prod',
+      },
+    });
+
+    const getLambdaIntegration = new apigateway.LambdaIntegration(lambdaFunction);
+
+    api.root.addProxy({
+      defaultIntegration: getLambdaIntegration,
+      anyMethod: true,
+    });
+
+    new cdk.CfnOutput(this, 'ApiUrl', {
+      value: api.url,
+      description: 'Invoke URL for cart service API',
+    });
+
+    new cdk.CfnOutput(this, 'DbSecretArn', {
+      value: database.secret?.secretArn || '',
+      description: 'Secrets Manager ARN containing DB credentials',
+    });
+  }
+}