{
    "AWSTemplateFormatVersion": "2010-09-09",

    "Description": "AWS CloudFormation Sample Template RDSDatabaseWithOptionalReadReplica.template: Sample template showing how to create a highly-available, RDS DBInstance version 5.6 with an optional 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": "8",
            "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": {
            "Default": "db.m1.small",
            "Description": "The database instance type",
            "Type": "String",
            "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.cr1.8xlarge"
            ],
            "ConstraintDescription": "must select a valid database instance type."
        },
        "EC2SecurityGroup": {
            "Default": "default",
            "Description": "The EC2 security group that contains instances that need access to the database",
            "Type": "String"
        },
        "MultiAZ": {
            "Description": "Multi-AZ master database",
            "Type": "String",
            "Default": "false",
            "AllowedValues": [
                "true",
                "false"
            ],
            "ConstraintDescription": "must be true or false."
        },
        "ReadReplica": {
            "Description": "Create a read replica",
            "Type": "String",
            "Default": "false",
            "AllowedValues": [
                "true",
                "false"
            ],
            "ConstraintDescription": "must be true or false."
        }
    },

    "Conditions" : {
      "CreateReadReplica" : { "Fn::Equals" : [ {"Ref" : "ReadReplica"}, "true"] }
    },

    "Resources": {
        "MasterDB": {
            "Type": "AWS::RDS::DBInstance",
            "Properties": {
                "DBName": { "Ref": "DBName" },
                "AllocatedStorage": { "Ref": "DBAllocatedStorage" },
                "DBInstanceClass": { "Ref": "DBInstanceClass" },
                "Engine": "MySQL",
                "EngineVersion": "5.6",
                "DBSecurityGroups": [ { "Ref": "DBSecurityGroup" } ],
                "MasterUsername": { "Ref": "DBUser" },
                "MasterUserPassword": { "Ref": "DBPassword" },
                "MultiAZ": { "Ref": "MultiAZ" },
                "Tags": [ { "Key": "Name", "Value": "Master Database" } ]
            },
            "DeletionPolicy": "Snapshot"
        },

        "ReplicaDB": {
            "Type": "AWS::RDS::DBInstance",
            "Condition" : "CreateReadReplica",
            "Properties": {
                "SourceDBInstanceIdentifier": { "Ref": "MasterDB" },
                "DBInstanceClass": { "Ref": "DBInstanceClass" },
                "Tags": [ { "Key": "Name", "Value": "Read Replica Database" } ]
            }
        },

        "DBSecurityGroup": {
            "Type": "AWS::RDS::DBSecurityGroup",
            "Properties": {
                "DBSecurityGroupIngress": { "EC2SecurityGroupName": { "Ref": "EC2SecurityGroup" } },
                "GroupDescription": "database access"
            }
        }
    },

    "Outputs": {
        "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": {
            "Condition" : "CreateReadReplica",
            "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" } ] ] }
        }
    }
}