{
  "AWSTemplateFormatVersion" : "2010-09-09",
  
  "Description" : "AWS CloudFormation Sample Template Rails_Single_Instance_With_RDS: Create a Ruby on Rails stack using a single EC2 instance for the web server and a MySQL Amazon RDS database instance for the backend data store. This template demonstrates using the AWS CloudFormation bootstrap scripts to install the packages and files at instance launch time. **WARNING** This template creates an Amazon EC2 instance and an Amazon RDS DB instance. You will be billed for the AWS resources used if you create a stack from this template.",
  
  "Parameters" : {
      
    "KeyName" : {
      "Description" : "Name of an existing EC2 KeyPair to enable SSH access to the instances",
      "Type" : "String",
      "MinLength": "1",
      "MaxLength": "64",
      "AllowedPattern" : "[-_ a-zA-Z0-9]*",
      "ConstraintDescription" : "can contain only alphanumeric characters, spaces, dashes and underscores."
    },    

    "DBName": {
      "Default": "MyDatabase",
      "Description" : "MySQL 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."
    },

    "DBUsername": {
      "NoEcho": "true",
      "Description" : "Username for MySQL database access",
      "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" : "Password for MySQL database access",
      "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": {
      "Default": "db.m1.small",
      "Description" : "The database instance type",
      "Type": "String",
      "AllowedValues" : [ "db.m1.small", "db.m1.large", "db.m1.xlarge", "db.m2.xlarge", "db.m2.2xlarge", "db.m2.4xlarge" ],
      "ConstraintDescription" : "must select a valid database instance type."
    },

    "InstanceType" : {
      "Description" : "WebServer EC2 instance type",
      "Type" : "String",
      "Default" : "m1.small",
      "AllowedValues" : [ "t1.micro", "m1.small", "m1.large", "m1.xlarge", "m2.xlarge", "m2.2xlarge", "m2.4xlarge", "c1.medium", "c1.xlarge", "cc1.4xlarge" ],
      "ConstraintDescription" : "must be a valid EC2 instance type."
    }
  
  },
  
  "Mappings" : {
    "AWSInstanceType2Arch" : {
      "t1.micro"    : { "Arch" : "32" },
      "m1.small"    : { "Arch" : "32" },
      "m1.large"    : { "Arch" : "64" },
      "m1.xlarge"   : { "Arch" : "64" },
      "m2.xlarge"   : { "Arch" : "64" },
      "m2.2xlarge"  : { "Arch" : "64" },
      "m2.4xlarge"  : { "Arch" : "64" },
      "c1.medium"   : { "Arch" : "32" },
      "c1.xlarge"   : { "Arch" : "64" },
      "cc1.4xlarge" : { "Arch" : "64" }
    },
    "AWSRegionArch2AMI" : {
      "us-east-1"      : { "32" : "ami-7f418316", "64" : "ami-7341831a" },
      "us-west-1"      : { "32" : "ami-951945d0", "64" : "ami-971945d2" },
      "us-west-2"      : { "32" : "ami-16fd7026", "64" : "ami-10fd7020" },
      "eu-west-1"      : { "32" : "ami-24506250", "64" : "ami-20506254" },
      "ap-southeast-1" : { "32" : "ami-74dda626", "64" : "ami-7edda62c" },
      "ap-northeast-1" : { "32" : "ami-dcfa4edd", "64" : "ami-e8fa4ee9" }
    }
  },
    
  "Resources" : {     
      
    "CfnUser" : {
      "Type" : "AWS::IAM::User",
      "Properties" : {
        "Path": "/",
        "Policies": [{
          "PolicyName": "root",
          "PolicyDocument": { "Statement":[{
            "Effect":"Allow",
            "Action":"cloudformation:DescribeStackResource",
            "Resource":"*"
          }]}
        }]
      }
    },

    "HostKeys" : {
      "Type" : "AWS::IAM::AccessKey",
      "Properties" : {
        "UserName" : {"Ref": "CfnUser"}
      }
    },

    "WebServer": {  
      "Type": "AWS::EC2::Instance",
      "Metadata" : {
        "Comment1" : "Configure the bootstrap helpers to install the Rails",
        "Comment2" : "The application is downloaded from the CloudFormationRailsSample.zip file",

        "AWS::CloudFormation::Init" : {
          "config" : {
            "packages" : {
              "yum" : {
                "gcc-c++"      : [],
                "make"         : [],
                "ruby-devel"   : [],
                "rubygems"     : [],
                "mysql"        : [],
                "mysql-devel"  : [],
                "mysql-libs"   : []
              },

              "rubygems" : {
                "execjs"       : [],
                "therubyracer" : [],
                "rails"        : []
              }
            },

            "sources" : {
              "/home/ec2-user/sample" : "https://s3.amazonaws.com/cloudformation-examples/CloudFormationRailsSample.zip"
            },

            "files" : {
              "/home/ec2-user/sample/config/database.yml" : {
               "content" : { "Fn::Join" : ["", [
                  "development:\n",
                  "  adapter: mysql2\n",
                  "  encoding: utf8\n",
                  "  reconnect: false\n",
                  "  pool: 5\n",
                  "  database: ", { "Ref" : "DBName" }, "\n",
                  "  username: ", { "Ref" : "DBUsername" }, "\n",
                  "  password: ", { "Ref" : "DBPassword" }, "\n",
                  "  host: ", { "Fn::GetAtt": [ "MySQLDatabase", "Endpoint.Address" ] }, "\n",
                  "  port: ", { "Fn::GetAtt": [ "MySQLDatabase", "Endpoint.Port" ] }, "\n"
                  ]]},
                "mode"  : "000644",
                "owner" : "root",
                "group" : "root"
              }
            }
          }
        }
      },
      "Properties": {
        "ImageId" : { "Fn::FindInMap" : [ "AWSRegionArch2AMI", { "Ref" : "AWS::Region" },
                          { "Fn::FindInMap" : [ "AWSInstanceType2Arch", { "Ref" : "InstanceType" }, "Arch" ] } ] },
        "InstanceType"   : { "Ref" : "InstanceType" },
        "SecurityGroups" : [ {"Ref" : "WebServerSecurityGroup"} ],
        "KeyName"        : { "Ref" : "KeyName" },
        "UserData"       : { "Fn::Base64" : { "Fn::Join" : ["", [
          "#!/bin/bash -v\n",
          "yum update -y aws-cfn-bootstrap\n",

          "# Helper function\n",
          "function error_exit\n",
          "{\n",
          "  /opt/aws/bin/cfn-signal -e 1 -r \"$1\" '", { "Ref" : "WaitHandle" }, "'\n",
          "  exit 1\n",
          "}\n",

          "# Install Rails packages\n",
          "/opt/aws/bin/cfn-init -s ", { "Ref" : "AWS::StackName" }, " -r WebServer ",
          "    --access-key ",  { "Ref" : "HostKeys" },
          "    --secret-key ", {"Fn::GetAtt": ["HostKeys", "SecretAccessKey"]},
          "    --region ", { "Ref" : "AWS::Region" }, " || error_exit 'Failed to run cfn-init'\n",

          "# Install anu other Gems, create the database and run a migration\n",
          "cd /home/ec2-user/sample\n",
          "bundle install  || error_exit 'Failed to install bundle'\n",
          "rake db:migrate || error_exit 'Failed to execute database migration'\n",

          "# Startup the rails server\n",
          "rails server -d\n", 
          "echo \"cd /home/ec2-user/sample\" >> /etc/rc.local\n",  
          "echo \"rails server -d\" >> /etc/rc.local\n",  

          "# All is well so signal success\n",
          "/opt/aws/bin/cfn-signal -e 0 -r \"Rails application setup complete\" '", { "Ref" : "WaitHandle" }, "'\n"
        ]]}}        
      }
    },

    "WaitHandle" : {
      "Type" : "AWS::CloudFormation::WaitConditionHandle"
    },

    "WaitCondition" : {
      "Type" : "AWS::CloudFormation::WaitCondition",
      "DependsOn" : "WebServer",
      "Properties" : {
        "Handle" : {"Ref" : "WaitHandle"},
        "Timeout" : "900"
      }
    },
    
    "WebServerSecurityGroup" : {
      "Type" : "AWS::EC2::SecurityGroup",
      "Properties" : {
        "GroupDescription" : "Enable HTTP access via port 3000 plus SSH access",
        "SecurityGroupIngress" : [
          {"IpProtocol" : "tcp", "FromPort" : "3000", "ToPort" : "3000", "CidrIp" : "0.0.0.0/0"},
          {"IpProtocol" : "tcp", "FromPort" : "22", "ToPort" : "22", "CidrIp" : "0.0.0.0/0"}
        ]
      }      
    },

    "DBSecurityGroup": {
      "Type": "AWS::RDS::DBSecurityGroup",
      "Properties": {
        "GroupDescription": "Grant database access to web server",
        "DBSecurityGroupIngress": {
          "EC2SecurityGroupName": { "Ref": "WebServerSecurityGroup" }
        }
      }
    },

    "MySQLDatabase": {
      "Type": "AWS::RDS::DBInstance",
      "Properties": {
        "Engine" : "MySQL",
        "DBName" : { "Ref": "DBName" },
        "MultiAZ" : "false",
        "MasterUsername": { "Ref": "DBUsername" },
        "MasterUserPassword": { "Ref" : "DBPassword" },
        "DBInstanceClass": { "Ref" : "DBInstanceClass" },
        "DBSecurityGroups": [ { "Ref": "DBSecurityGroup" } ],
        "AllocatedStorage": { "Ref" : "DBAllocatedStorage" }
      }
    }
  },
  
  "Outputs" : {
    "WebsiteURL" : {
      "Value" : { "Fn::Join" : ["", ["http://", { "Fn::GetAtt" : [ "WebServer", "PublicDnsName" ]}, ":3000" ]] },
      "Description" : "URL for newly created Rails application"
    }
  }
}