RDS Multi-AZ Deployment Disabled

  • Query id: 2b1d4935-9acf-48a7-8466-10d18bf51a69
  • Query name: RDS Multi-AZ Deployment Disabled
  • Platform: CloudFormation
  • Severity: Medium
  • Category: Backup
  • URL: Github

Description

AWS RDS Instance should have a multi-az deployment
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - yaml file
AWSTemplateFormatVersion: 2010-09-09
Description: "AWS CloudFormation Sample Template RDS_MySQL_With_Read_Replica:
  Sample template showing how to create a highly-available, RDS DBInstance with
  a read replica. **WARNING** This template creates an Amazon Relational
  Database Service database instance and Amazon CloudWatch alarms. You will be
  billed for the AWS resources used if you create a stack from this template."
Parameters:
  DBName:
    Default: MyDatabase
    Description: The database name
    Type: String
    MinLength: "1"
    MaxLength: "64"
    AllowedPattern: "[a-zA-Z][a-zA-Z0-9]*"
    ConstraintDescription: must begin with a letter and contain only alphanumeric characters.
  DBUser:
    NoEcho: "true"
    Description: The database admin account username
    Type: String
    MinLength: "1"
    MaxLength: "16"
    AllowedPattern: "[a-zA-Z][a-zA-Z0-9]*"
    ConstraintDescription: must begin with a letter and contain only alphanumeric characters.
  DBPassword:
    NoEcho: "true"
    Description: The database admin account password
    Type: String
    MinLength: "1"
    MaxLength: "41"
    AllowedPattern: "[a-zA-Z0-9]+"
    ConstraintDescription: must contain only alphanumeric characters.
  DBAllocatedStorage:
    Default: "5"
    Description: The size of the database (Gb)
    Type: Number
    MinValue: "5"
    MaxValue: "1024"
    ConstraintDescription: must be between 5 and 1024Gb.
  DBInstanceClass:
    Description: The database instance type
    Type: String
    Default: db.t2.small
    AllowedValues:
      - db.t1.micro
      - db.m1.small
      - db.m1.medium
      - db.m1.large
      - db.m1.xlarge
      - db.m2.xlarge
      - db.m2.2xlarge
      - db.m2.4xlarge
      - db.m3.medium
      - db.m3.large
      - db.m3.xlarge
      - db.m3.2xlarge
      - db.m4.large
      - db.m4.xlarge
      - db.m4.2xlarge
      - db.m4.4xlarge
      - db.m4.10xlarge
      - db.r3.large
      - db.r3.xlarge
      - db.r3.2xlarge
      - db.r3.4xlarge
      - db.r3.8xlarge
      - db.m2.xlarge
      - db.m2.2xlarge
      - db.m2.4xlarge
      - db.cr1.8xlarge
      - db.t2.micro
      - db.t2.small
      - db.t2.medium
      - db.t2.large
    ConstraintDescription: must select a valid database instance type.
  EC2SecurityGroup:
    Description: The EC2 security group that contains instances that need access to
      the database
    Default: default
    Type: String
    AllowedPattern: "[a-zA-Z0-9\\-]+"
    ConstraintDescription: must be a valid security group name.
Conditions:
  Is-EC2-VPC:
    Fn::Or:
      - Fn::Equals:
          - Ref: AWS::Region
          - eu-central-1
      - Fn::Equals:
          - Ref: AWS::Region
          - cn-north-1
  Is-EC2-Classic:
    Fn::Not:
      - Condition: Is-EC2-VPC
Resources:
  DBEC2SecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Condition: Is-EC2-VPC
    Properties:
      GroupDescription: Open database for access
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 3306
          ToPort: 3306
          SourceSecurityGroupName:
            Ref: EC2SecurityGroup
  DBSecurityGroup:
    Type: AWS::RDS::DBSecurityGroup
    Condition: Is-EC2-Classic
    Properties:
      DBSecurityGroupIngress:
        - EC2SecurityGroupName:
            Ref: EC2SecurityGroup
      GroupDescription: database access
  MasterDB:
    Type: AWS::RDS::DBInstance
    Properties:
      DBName:
        Ref: DBName
      AllocatedStorage:
        Ref: DBAllocatedStorage
      DBInstanceClass:
        Ref: DBInstanceClass
      Engine: MySQL
      MasterUsername:
        Ref: DBUser
      MasterUserPassword:
        Ref: DBPassword
      MultiAZ: false
      Tags:
        - Key: Name
          Value: Master Database
      VPCSecurityGroups:
        Fn::If:
          - Is-EC2-VPC
          - - Fn::GetAtt:
                - DBEC2SecurityGroup
                - GroupId
          - Ref: AWS::NoValue
      DBSecurityGroups:
        Fn::If:
          - Is-EC2-Classic
          - - Ref: DBSecurityGroup
          - Ref: AWS::NoValue
    DeletionPolicy: Snapshot
    UpdateReplacePolicy: Snapshot
  ReplicaDB:
    Type: AWS::RDS::DBInstance
    Properties:
      SourceDBInstanceIdentifier:
        Ref: MasterDB
      DBInstanceClass:
        Ref: DBInstanceClass
      Tags:
        - Key: Name
          Value: Read Replica Database
Outputs:
  EC2Platform:
    Description: Platform in which this stack is deployed
    Value:
      Fn::If:
        - Is-EC2-VPC
        - EC2-VPC
        - EC2-Classic
  MasterJDBCConnectionString:
    Description: JDBC connection string for the master database
    Value:
      Fn::Join:
        - ""
        - - jdbc:mysql://
          - Fn::GetAtt:
              - MasterDB
              - Endpoint.Address
          - ":"
          - Fn::GetAtt:
              - MasterDB
              - Endpoint.Port
          - /
          - Ref: DBName
  ReplicaJDBCConnectionString:
    Description: JDBC connection string for the replica database
    Value:
      Fn::Join:
        - ""
        - - jdbc:mysql://
          - Fn::GetAtt:
              - ReplicaDB
              - Endpoint.Address
          - ":"
          - Fn::GetAtt:
              - ReplicaDB
              - Endpoint.Port
          - /
          - Ref: DBName
Positive test num. 2 - json file
{
  "Conditions": {
    "Is-EC2-VPC": {
      "Fn::Or": [
        {
          "Fn::Equals": [
            {
              "Ref": "AWS::Region"
            },
            "eu-central-1"
          ]
        },
        {
          "Fn::Equals": [
            {
              "Ref": "AWS::Region"
            },
            "cn-north-1"
          ]
        }
      ]
    },
    "Is-EC2-Classic": {
      "Fn::Not": [
        {
          "Condition": "Is-EC2-VPC"
        }
      ]
    }
  },
  "Resources": {
    "DBEC2SecurityGroup": {
      "Type": "AWS::EC2::SecurityGroup",
      "Condition": "Is-EC2-VPC",
      "Properties": {
        "GroupDescription": "Open database for access",
        "SecurityGroupIngress": [
          {
            "IpProtocol": "tcp",
            "FromPort": 3306,
            "ToPort": 3306,
            "SourceSecurityGroupName": {
              "Ref": "EC2SecurityGroup"
            }
          }
        ]
      }
    },
    "DBSecurityGroup": {
      "Type": "AWS::RDS::DBSecurityGroup",
      "Condition": "Is-EC2-Classic",
      "Properties": {
        "GroupDescription": "database access",
        "DBSecurityGroupIngress": [
          {
            "EC2SecurityGroupName": {
              "Ref": "EC2SecurityGroup"
            }
          }
        ]
      }
    },
    "MasterDB": {
      "Type": "AWS::RDS::DBInstance",
      "Properties": {
        "DBSecurityGroups": {
          "Fn::If": [
            "Is-EC2-Classic",
            [
              {
                "Ref": "DBSecurityGroup"
              }
            ],
            {
              "Ref": "AWS::NoValue"
            }
          ]
        },
        "DBName": {
          "Ref": "DBName"
        },
        "DBInstanceClass": {
          "Ref": "DBInstanceClass"
        },
        "Engine": "MySQL",
        "MasterUserPassword": {
          "Ref": "DBPassword"
        },
        "MultiAZ": false,
        "AllocatedStorage": {
          "Ref": "DBAllocatedStorage"
        },
        "MasterUsername": {
          "Ref": "DBUser"
        },
        "Tags": [
          {
            "Key": "Name",
            "Value": "Master Database"
          }
        ],
        "VPCSecurityGroups": {
          "Fn::If": [
            "Is-EC2-VPC",
            [
              {
                "Fn::GetAtt": [
                  "DBEC2SecurityGroup",
                  "GroupId"
                ]
              }
            ],
            {
              "Ref": "AWS::NoValue"
            }
          ]
        }
      },
      "DeletionPolicy": "Snapshot",
      "UpdateReplacePolicy": "Snapshot"
    },
    "ReplicaDB": {
      "Type": "AWS::RDS::DBInstance",
      "Properties": {
        "SourceDBInstanceIdentifier": {
          "Ref": "MasterDB"
        },
        "DBInstanceClass": {
          "Ref": "DBInstanceClass"
        },
        "Tags": [
          {
            "Key": "Name",
            "Value": "Read Replica Database"
          }
        ]
      }
    }
  },
  "Outputs": {
    "ReplicaJDBCConnectionString": {
      "Description": "JDBC connection string for the replica database",
      "Value": {
        "Fn::Join": [
          "",
          [
            "jdbc:mysql://",
            {
              "Fn::GetAtt": [
                "ReplicaDB",
                "Endpoint.Address"
              ]
            },
            ":",
            {
              "Fn::GetAtt": [
                "ReplicaDB",
                "Endpoint.Port"
              ]
            },
            "/",
            {
              "Ref": "DBName"
            }
          ]
        ]
      }
    },
    "EC2Platform": {
      "Description": "Platform in which this stack is deployed",
      "Value": {
        "Fn::If": [
          "Is-EC2-VPC",
          "EC2-VPC",
          "EC2-Classic"
        ]
      }
    },
    "MasterJDBCConnectionString": {
      "Description": "JDBC connection string for the master database",
      "Value": {
        "Fn::Join": [
          "",
          [
            "jdbc:mysql://",
            {
              "Fn::GetAtt": [
                "MasterDB",
                "Endpoint.Address"
              ]
            },
            ":",
            {
              "Fn::GetAtt": [
                "MasterDB",
                "Endpoint.Port"
              ]
            },
            "/",
            {
              "Ref": "DBName"
            }
          ]
        ]
      }
    }
  },
  "AWSTemplateFormatVersion": "2010-09-09T00:00:00Z",
  "Description": "AWS CloudFormation Sample Template RDS_MySQL_With_Read_Replica: Sample template showing how to create a highly-available, RDS DBInstance with a read replica. **WARNING** This template creates an Amazon Relational Database Service database instance and Amazon CloudWatch alarms. You will be billed for the AWS resources used if you create a stack from this template.",
  "Parameters": {
    "DBAllocatedStorage": {
      "MaxValue": "1024",
      "ConstraintDescription": "must be between 5 and 1024Gb.",
      "Default": "5",
      "Description": "The size of the database (Gb)",
      "Type": "Number",
      "MinValue": "5"
    },
    "DBInstanceClass": {
      "AllowedValues": [
        "db.t1.micro",
        "db.m1.small",
        "db.m1.medium",
        "db.m1.large",
        "db.m1.xlarge",
        "db.m2.xlarge",
        "db.m2.2xlarge",
        "db.m2.4xlarge",
        "db.m3.medium",
        "db.m3.large",
        "db.m3.xlarge",
        "db.m3.2xlarge",
        "db.m4.large",
        "db.m4.xlarge",
        "db.m4.2xlarge",
        "db.m4.4xlarge",
        "db.m4.10xlarge",
        "db.r3.large",
        "db.r3.xlarge",
        "db.r3.2xlarge",
        "db.r3.4xlarge",
        "db.r3.8xlarge",
        "db.m2.xlarge",
        "db.m2.2xlarge",
        "db.m2.4xlarge",
        "db.cr1.8xlarge",
        "db.t2.micro",
        "db.t2.small",
        "db.t2.medium",
        "db.t2.large"
      ],
      "ConstraintDescription": "must select a valid database instance type.",
      "Description": "The database instance type",
      "Type": "String",
      "Default": "db.t2.small"
    },
    "EC2SecurityGroup": {
      "AllowedPattern": "[a-zA-Z0-9\\-]+",
      "ConstraintDescription": "must be a valid security group name.",
      "Description": "The EC2 security group that contains instances that need access to the database",
      "Default": "default",
      "Type": "String"
    },
    "DBName": {
      "Default": "MyDatabase",
      "Description": "The database name",
      "Type": "String",
      "MinLength": "1",
      "MaxLength": "64",
      "AllowedPattern": "[a-zA-Z][a-zA-Z0-9]*",
      "ConstraintDescription": "must begin with a letter and contain only alphanumeric characters."
    },
    "DBUser": {
      "NoEcho": "true",
      "Description": "The database admin account username",
      "Type": "String",
      "MinLength": "1",
      "MaxLength": "16",
      "AllowedPattern": "[a-zA-Z][a-zA-Z0-9]*",
      "ConstraintDescription": "must begin with a letter and contain only alphanumeric characters."
    },
    "DBPassword": {
      "NoEcho": "true",
      "Description": "The database admin account password",
      "Type": "String",
      "MinLength": "1",
      "MaxLength": "41",
      "AllowedPattern": "[a-zA-Z0-9]+",
      "ConstraintDescription": "must contain only alphanumeric characters."
    }
  }
}

Code samples without security vulnerabilities

Negative test num. 1 - yaml file
AWSTemplateFormatVersion: 2010-09-09
Description: "AWS CloudFormation Sample Template RDS_MySQL_With_Read_Replica:
  Sample template showing how to create a highly-available, RDS DBInstance with
  a read replica. **WARNING** This template creates an Amazon Relational
  Database Service database instance and Amazon CloudWatch alarms. You will be
  billed for the AWS resources used if you create a stack from this template."
Parameters:
  DBName:
    Default: MyDatabase
    Description: The database name
    Type: String
    MinLength: "1"
    MaxLength: "64"
    AllowedPattern: "[a-zA-Z][a-zA-Z0-9]*"
    ConstraintDescription: must begin with a letter and contain only alphanumeric characters.
  DBUser:
    NoEcho: "true"
    Description: The database admin account username
    Type: String
    MinLength: "1"
    MaxLength: "16"
    AllowedPattern: "[a-zA-Z][a-zA-Z0-9]*"
    ConstraintDescription: must begin with a letter and contain only alphanumeric characters.
  DBPassword:
    NoEcho: "true"
    Description: The database admin account password
    Type: String
    MinLength: "1"
    MaxLength: "41"
    AllowedPattern: "[a-zA-Z0-9]+"
    ConstraintDescription: must contain only alphanumeric characters.
  DBAllocatedStorage:
    Default: "5"
    Description: The size of the database (Gb)
    Type: Number
    MinValue: "5"
    MaxValue: "1024"
    ConstraintDescription: must be between 5 and 1024Gb.
  DBInstanceClass:
    Description: The database instance type
    Type: String
    Default: db.t2.small
    AllowedValues:
      - db.t1.micro
      - db.m1.small
      - db.m1.medium
      - db.m1.large
      - db.m1.xlarge
      - db.m2.xlarge
      - db.m2.2xlarge
      - db.m2.4xlarge
      - db.m3.medium
      - db.m3.large
      - db.m3.xlarge
      - db.m3.2xlarge
      - db.m4.large
      - db.m4.xlarge
      - db.m4.2xlarge
      - db.m4.4xlarge
      - db.m4.10xlarge
      - db.r3.large
      - db.r3.xlarge
      - db.r3.2xlarge
      - db.r3.4xlarge
      - db.r3.8xlarge
      - db.m2.xlarge
      - db.m2.2xlarge
      - db.m2.4xlarge
      - db.cr1.8xlarge
      - db.t2.micro
      - db.t2.small
      - db.t2.medium
      - db.t2.large
    ConstraintDescription: must select a valid database instance type.
  EC2SecurityGroup:
    Description: The EC2 security group that contains instances that need access to
      the database
    Default: default
    Type: String
    AllowedPattern: "[a-zA-Z0-9\\-]+"
    ConstraintDescription: must be a valid security group name.
Conditions:
  Is-EC2-VPC:
    Fn::Or:
      - Fn::Equals:
          - Ref: AWS::Region
          - eu-central-1
      - Fn::Equals:
          - Ref: AWS::Region
          - cn-north-1
  Is-EC2-Classic:
    Fn::Not:
      - Condition: Is-EC2-VPC
Resources:
  DBEC2SecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Condition: Is-EC2-VPC
    Properties:
      GroupDescription: Open database for access
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 3306
          ToPort: 3306
          SourceSecurityGroupName:
            Ref: EC2SecurityGroup
  DBSecurityGroup:
    Type: AWS::RDS::DBSecurityGroup
    Condition: Is-EC2-Classic
    Properties:
      DBSecurityGroupIngress:
        - EC2SecurityGroupName:
            Ref: EC2SecurityGroup
      GroupDescription: database access
  MasterDB:
    Type: AWS::RDS::DBInstance
    Properties:
      DBName:
        Ref: DBName
      AllocatedStorage:
        Ref: DBAllocatedStorage
      DBInstanceClass:
        Ref: DBInstanceClass
      Engine: MySQL
      MasterUsername:
        Ref: DBUser
      MasterUserPassword:
        Ref: DBPassword
      MultiAZ: true
      Tags:
        - Key: Name
          Value: Master Database
      VPCSecurityGroups:
        Fn::If:
          - Is-EC2-VPC
          - - Fn::GetAtt:
                - DBEC2SecurityGroup
                - GroupId
          - Ref: AWS::NoValue
      DBSecurityGroups:
        Fn::If:
          - Is-EC2-Classic
          - - Ref: DBSecurityGroup
          - Ref: AWS::NoValue
    DeletionPolicy: Snapshot
    UpdateReplacePolicy: Snapshot
  ReplicaDB:
    Type: AWS::RDS::DBInstance
    Properties:
      SourceDBInstanceIdentifier:
        Ref: MasterDB
      DBInstanceClass:
        Ref: DBInstanceClass
      MultiAZ: true
      Tags:
        - Key: Name
          Value: Read Replica Database
Outputs:
  EC2Platform:
    Description: Platform in which this stack is deployed
    Value:
      Fn::If:
        - Is-EC2-VPC
        - EC2-VPC
        - EC2-Classic
  MasterJDBCConnectionString:
    Description: JDBC connection string for the master database
    Value:
      Fn::Join:
        - ""
        - - jdbc:mysql://
          - Fn::GetAtt:
              - MasterDB
              - Endpoint.Address
          - ":"
          - Fn::GetAtt:
              - MasterDB
              - Endpoint.Port
          - /
          - Ref: DBName
  ReplicaJDBCConnectionString:
    Description: JDBC connection string for the replica database
    Value:
      Fn::Join:
        - ""
        - - jdbc:mysql://
          - Fn::GetAtt:
              - ReplicaDB
              - Endpoint.Address
          - ":"
          - Fn::GetAtt:
              - ReplicaDB
              - Endpoint.Port
          - /
          - Ref: DBName
Negative test num. 2 - json file
{
  "Resources": {
    "DBEC2SecurityGroup": {
      "Type": "AWS::EC2::SecurityGroup",
      "Condition": "Is-EC2-VPC",
      "Properties": {
        "GroupDescription": "Open database for access",
        "SecurityGroupIngress": [
          {
            "IpProtocol": "tcp",
            "FromPort": 3306,
            "ToPort": 3306,
            "SourceSecurityGroupName": {
              "Ref": "EC2SecurityGroup"
            }
          }
        ]
      }
    },
    "DBSecurityGroup": {
      "Type": "AWS::RDS::DBSecurityGroup",
      "Condition": "Is-EC2-Classic",
      "Properties": {
        "DBSecurityGroupIngress": [
          {
            "EC2SecurityGroupName": {
              "Ref": "EC2SecurityGroup"
            }
          }
        ],
        "GroupDescription": "database access"
      }
    },
    "MasterDB": {
      "Type": "AWS::RDS::DBInstance",
      "Properties": {
        "VPCSecurityGroups": {
          "Fn::If": [
            "Is-EC2-VPC",
            [
              {
                "Fn::GetAtt": [
                  "DBEC2SecurityGroup",
                  "GroupId"
                ]
              }
            ],
            {
              "Ref": "AWS::NoValue"
            }
          ]
        },
        "DBSecurityGroups": {
          "Fn::If": [
            "Is-EC2-Classic",
            [
              {
                "Ref": "DBSecurityGroup"
              }
            ],
            {
              "Ref": "AWS::NoValue"
            }
          ]
        },
        "DBName": {
          "Ref": "DBName"
        },
        "AllocatedStorage": {
          "Ref": "DBAllocatedStorage"
        },
        "DBInstanceClass": {
          "Ref": "DBInstanceClass"
        },
        "MasterUserPassword": {
          "Ref": "DBPassword"
        },
        "MultiAZ": true,
        "Engine": "MySQL",
        "MasterUsername": {
          "Ref": "DBUser"
        },
        "Tags": [
          {
            "Key": "Name",
            "Value": "Master Database"
          }
        ]
      },
      "DeletionPolicy": "Snapshot",
      "UpdateReplacePolicy": "Snapshot"
    },
    "ReplicaDB": {
      "Type": "AWS::RDS::DBInstance",
      "Properties": {
        "SourceDBInstanceIdentifier": {
          "Ref": "MasterDB"
        },
        "DBInstanceClass": {
          "Ref": "DBInstanceClass"
        },
        "MultiAZ": true,
        "Tags": [
          {
            "Key": "Name",
            "Value": "Read Replica Database"
          }
        ]
      }
    }
  },
  "Outputs": {
    "EC2Platform": {
      "Description": "Platform in which this stack is deployed",
      "Value": {
        "Fn::If": [
          "Is-EC2-VPC",
          "EC2-VPC",
          "EC2-Classic"
        ]
      }
    },
    "MasterJDBCConnectionString": {
      "Description": "JDBC connection string for the master database",
      "Value": {
        "Fn::Join": [
          "",
          [
            "jdbc:mysql://",
            {
              "Fn::GetAtt": [
                "MasterDB",
                "Endpoint.Address"
              ]
            },
            ":",
            {
              "Fn::GetAtt": [
                "MasterDB",
                "Endpoint.Port"
              ]
            },
            "/",
            {
              "Ref": "DBName"
            }
          ]
        ]
      }
    },
    "ReplicaJDBCConnectionString": {
      "Description": "JDBC connection string for the replica database",
      "Value": {
        "Fn::Join": [
          "",
          [
            "jdbc:mysql://",
            {
              "Fn::GetAtt": [
                "ReplicaDB",
                "Endpoint.Address"
              ]
            },
            ":",
            {
              "Fn::GetAtt": [
                "ReplicaDB",
                "Endpoint.Port"
              ]
            },
            "/",
            {
              "Ref": "DBName"
            }
          ]
        ]
      }
    }
  },
  "AWSTemplateFormatVersion": "2010-09-09T00:00:00Z",
  "Description": "AWS CloudFormation Sample Template RDS_MySQL_With_Read_Replica: Sample template showing how to create a highly-available, RDS DBInstance with a read replica. **WARNING** This template creates an Amazon Relational Database Service database instance and Amazon CloudWatch alarms. You will be billed for the AWS resources used if you create a stack from this template.",
  "Parameters": {
    "DBName": {
      "MaxLength": "64",
      "AllowedPattern": "[a-zA-Z][a-zA-Z0-9]*",
      "ConstraintDescription": "must begin with a letter and contain only alphanumeric characters.",
      "Default": "MyDatabase",
      "Description": "The database name",
      "Type": "String",
      "MinLength": "1"
    },
    "DBUser": {
      "NoEcho": "true",
      "Description": "The database admin account username",
      "Type": "String",
      "MinLength": "1",
      "MaxLength": "16",
      "AllowedPattern": "[a-zA-Z][a-zA-Z0-9]*",
      "ConstraintDescription": "must begin with a letter and contain only alphanumeric characters."
    },
    "DBPassword": {
      "NoEcho": "true",
      "Description": "The database admin account password",
      "Type": "String",
      "MinLength": "1",
      "MaxLength": "41",
      "AllowedPattern": "[a-zA-Z0-9]+",
      "ConstraintDescription": "must contain only alphanumeric characters."
    },
    "DBAllocatedStorage": {
      "Default": "5",
      "Description": "The size of the database (Gb)",
      "Type": "Number",
      "MinValue": "5",
      "MaxValue": "1024",
      "ConstraintDescription": "must be between 5 and 1024Gb."
    },
    "DBInstanceClass": {
      "Type": "String",
      "Default": "db.t2.small",
      "AllowedValues": [
        "db.t1.micro",
        "db.m1.small",
        "db.m1.medium",
        "db.m1.large",
        "db.m1.xlarge",
        "db.m2.xlarge",
        "db.m2.2xlarge",
        "db.m2.4xlarge",
        "db.m3.medium",
        "db.m3.large",
        "db.m3.xlarge",
        "db.m3.2xlarge",
        "db.m4.large",
        "db.m4.xlarge",
        "db.m4.2xlarge",
        "db.m4.4xlarge",
        "db.m4.10xlarge",
        "db.r3.large",
        "db.r3.xlarge",
        "db.r3.2xlarge",
        "db.r3.4xlarge",
        "db.r3.8xlarge",
        "db.m2.xlarge",
        "db.m2.2xlarge",
        "db.m2.4xlarge",
        "db.cr1.8xlarge",
        "db.t2.micro",
        "db.t2.small",
        "db.t2.medium",
        "db.t2.large"
      ],
      "ConstraintDescription": "must select a valid database instance type.",
      "Description": "The database instance type"
    },
    "EC2SecurityGroup": {
      "Default": "default",
      "Type": "String",
      "AllowedPattern": "[a-zA-Z0-9\\-]+",
      "ConstraintDescription": "must be a valid security group name.",
      "Description": "The EC2 security group that contains instances that need access to the database"
    }
  },
  "Conditions": {
    "Is-EC2-VPC": {
      "Fn::Or": [
        {
          "Fn::Equals": [
            {
              "Ref": "AWS::Region"
            },
            "eu-central-1"
          ]
        },
        {
          "Fn::Equals": [
            {
              "Ref": "AWS::Region"
            },
            "cn-north-1"
          ]
        }
      ]
    },
    "Is-EC2-Classic": {
      "Fn::Not": [
        {
          "Condition": "Is-EC2-VPC"
        }
      ]
    }
  }
}