---
AWSTemplateFormatVersion: 2010-09-09

Description: Reference Architecture to host Moodle on AWS - Creates VPC security groups

Metadata:
  AWS::CloudFormation::Interface:
    ParameterGroups:
    - Label:
        default: AWS Parameters
      Parameters:
        - SshAccessCidr
        - Vpc
    ParameterLabels:
      SshAccessCidr:
        default: SSH Access From
      Vpc:
        default: Vpc Id

Parameters:
  SshAccessCidr:
    AllowedPattern: ^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/([0-9]|[1-2][0-9]|3[0-2]))$
    Description: The CIDR IP range that is permitted to SSH to bastion instance. Note - a value of 0.0.0.0/0 will allow access from ANY IP address.
    Type: String
    Default: 0.0.0.0/0
  Vpc:
    AllowedPattern: ^(vpc-)([a-z0-9]{8}|[a-z0-9]{17})$
    Description: The Vpc Id of an existing Vpc.
    Type: AWS::EC2::VPC::Id
  DatabaseType:
    AllowedValues:
      - MySQL
      - PostgreSQL
    Default: PostgreSQL
    Description: Indicates whether to use Aurora MySQL or PostgreSQL.
    Type: String
Conditions:
  UsePostgreSQL:
    !Equals [!Ref DatabaseType, PostgreSQL]  
Resources:

  BastionSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for Bastion instances
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 22
          ToPort: 22
          CidrIp: !Ref SshAccessCidr
      VpcId:
        !Ref Vpc

  DatabaseSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for Amazon RDS cluster
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: !If [ UsePostgreSQL, 5432, 3306 ]
          ToPort: !If [ UsePostgreSQL, 5432, 3306 ]
          SourceSecurityGroupId: !Ref WebSecurityGroup
      VpcId:
        !Ref Vpc

  ElastiCacheSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for ElastiCache cache cluster
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 11211
          ToPort: 11211
          SourceSecurityGroupId: !Ref WebSecurityGroup
        - IpProtocol: tcp
          FromPort: 6379
          ToPort: 6379
          SourceSecurityGroupId: !Ref WebSecurityGroup
      VpcId:
        !Ref Vpc
  EfsSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for EFS mount targets
      VpcId: !Ref Vpc
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 2049
          ToPort: 2049
          SourceSecurityGroupId: !Ref WebSecurityGroup
        - IpProtocol: tcp
          FromPort: 22
          ToPort: 22
          SourceSecurityGroupId: !Ref BastionSecurityGroup
  EfsSecurityGroupIngress:
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      IpProtocol: tcp
      FromPort: 2049
      ToPort: 2049
      SourceSecurityGroupId: !GetAtt EfsSecurityGroup.GroupId
      GroupId: !GetAtt EfsSecurityGroup.GroupId

  PublicAlbSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for ALB
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 443
          ToPort: 443
          CidrIp: 0.0.0.0/0
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
      VpcId:
        !Ref Vpc       

  WebSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security group for web instances
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          SourceSecurityGroupId: !Ref PublicAlbSecurityGroup
        - IpProtocol: tcp
          FromPort: 443
          ToPort: 443
          SourceSecurityGroupId: !Ref PublicAlbSecurityGroup
        - IpProtocol: tcp
          FromPort: 22
          ToPort: 22
          SourceSecurityGroupId: !Ref BastionSecurityGroup
      VpcId:
        !Ref Vpc

Outputs:
  BastionSecurityGroup:
    Value: !Ref BastionSecurityGroup
  DatabaseSecurityGroup:
    Value: !Ref DatabaseSecurityGroup
  EfsSecurityGroup:
    Value: !Ref EfsSecurityGroup
  ElastiCacheSecurityGroup:
    Value: !Ref ElastiCacheSecurityGroup
  PublicAlbSecurityGroup:
    Value: !Ref PublicAlbSecurityGroup
  WebSecurityGroup:
    Value: !Ref WebSecurityGroup