aws-infrastructure.yml

AWSTemplateFormatVersion: '2010-09-09'
Description: 'Yelp App Infrastructure - Cost-Optimized'

Parameters:
  DBPassword:
    Type: String
    NoEcho: true
    Description: 'Database password'
    MinLength: 8

Resources:
  # VPC and Network
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.0.0.0/16
      EnableDnsHostnames: true
      Tags:
        - Key: Name
          Value: yelp-app-vpc

  PublicSubnet1:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.1.0/24
      AvailabilityZone: !Select [0, !GetAZs '']
      MapPublicIpOnLaunch: true

  PublicSubnet2:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.2.0/24
      AvailabilityZone: !Select [1, !GetAZs '']
      MapPublicIpOnLaunch: true

  PrivateSubnet1:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.3.0/24
      AvailabilityZone: !Select [0, !GetAZs '']

  PrivateSubnet2:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.4.0/24
      AvailabilityZone: !Select [1, !GetAZs '']

  InternetGateway:
    Type: AWS::EC2::InternetGateway

  AttachGateway:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !Ref VPC
      InternetGatewayId: !Ref InternetGateway

  PublicRouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC

  PublicRoute:
    Type: AWS::EC2::Route
    DependsOn: AttachGateway
    Properties:
      RouteTableId: !Ref PublicRouteTable
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref InternetGateway

  PublicSubnetRouteTableAssociation1:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnet1
      RouteTableId: !Ref PublicRouteTable

  PublicSubnetRouteTableAssociation2:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnet2
      RouteTableId: !Ref PublicRouteTable

  # Database
  DBSubnetGroup:
    Type: AWS::RDS::DBSubnetGroup
    Properties:
      DBSubnetGroupDescription: Subnet group for RDS database
      SubnetIds:
        - !Ref PrivateSubnet1
        - !Ref PrivateSubnet2
      Tags:
        - Key: Name
          Value: yelp-db-subnet-group

  DatabaseSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for RDS database
      VpcId: !Ref VPC
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 5432
          ToPort: 5432
          SourceSecurityGroupId: !Ref FargateSecurityGroup

  Database:
    Type: AWS::RDS::DBInstance
    Properties:
      DBInstanceIdentifier: yelp-postgres
      DBInstanceClass: db.t3.micro  # Cheapest option
      Engine: postgres
      EngineVersion: '15.4'
      AllocatedStorage: 20  # Minimum
      StorageType: gp2
      DBName: yelpdb
      MasterUsername: postgres
      MasterUserPassword: !Ref DBPassword
      VPCSecurityGroups:
        - !Ref DatabaseSecurityGroup
      DBSubnetGroupName: !Ref DBSubnetGroup
      BackupRetentionPeriod: 7
      DeleteAutomatedBackups: true
      DeletionProtection: false

  # ECS Cluster and Fargate Service
  ECSCluster:
    Type: AWS::ECS::Cluster
    Properties:
      ClusterName: yelp-app-cluster

  FargateSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for Fargate tasks
      VpcId: !Ref VPC
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 8000
          ToPort: 8000
          SourceSecurityGroupId: !Ref ALBSecurityGroup

  ALBSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for Application Load Balancer
      VpcId: !Ref VPC
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
        - IpProtocol: tcp
          FromPort: 443
          ToPort: 443
          CidrIp: 0.0.0.0/0

  ApplicationLoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Name: yelp-app-alb
      Scheme: internet-facing
      SecurityGroups:
        - !Ref ALBSecurityGroup
      Subnets:
        - !Ref PublicSubnet1
        - !Ref PublicSubnet2

  # S3 Bucket for Frontend
  FrontendBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: !Sub 'yelp-frontend-${AWS::AccountId}-${AWS::Region}'
      WebsiteConfiguration:
        IndexDocument: index.html
        ErrorDocument: error.html
      PublicAccessBlockConfiguration:
        BlockPublicAcls: false
        BlockPublicPolicy: false
        IgnorePublicAcls: false
        RestrictPublicBuckets: false

  FrontendBucketPolicy:
    Type: AWS::S3::BucketPolicy
    Properties:
      Bucket: !Ref FrontendBucket
      PolicyDocument:
        Statement:
          - Effect: Allow
            Principal: '*'
            Action: s3:GetObject
            Resource: !Sub '${FrontendBucket}/*'

  # CloudFront Distribution
  CloudFrontDistribution:
    Type: AWS::CloudFront::Distribution
    Properties:
      DistributionConfig:
        Origins:
          - DomainName: !GetAtt FrontendBucket.RegionalDomainName
            Id: S3Origin
            S3OriginConfig:
              OriginAccessIdentity: ''
        Enabled: true
        DefaultRootObject: index.html
        DefaultCacheBehavior:
          TargetOriginId: S3Origin
          ViewerProtocolPolicy: redirect-to-https
          AllowedMethods:
            - GET
            - HEAD
          CachedMethods:
            - GET
            - HEAD
          ForwardedValues:
            QueryString: false
            Cookies:
              Forward: none
        CustomErrorResponses:
          - ErrorCode: 404
            ResponseCode: 200
            ResponsePagePath: /index.html

Outputs:
  DatabaseEndpoint:
    Description: 'Database endpoint'
    Value: !GetAtt Database.Endpoint.Address
    Export:
      Name: !Sub '${AWS::StackName}-DatabaseEndpoint'

  LoadBalancerDNS:
    Description: 'Load Balancer DNS name'
    Value: !GetAtt ApplicationLoadBalancer.DNSName
    Export:
      Name: !Sub '${AWS::StackName}-LoadBalancerDNS'

  CloudFrontDomain:
    Description: 'CloudFront distribution domain'
    Value: !GetAtt CloudFrontDistribution.DomainName
    Export:
      Name: !Sub '${AWS::StackName}-CloudFrontDomain'

  S3BucketName:
    Description: 'S3 bucket for frontend'
    Value: !Ref FrontendBucket
    Export:
      Name: !Sub '${AWS::StackName}-S3Bucket'