CloudFormation do
  Description("AWS CloudFormation Sample Template Gollum_Single_Instance_With_EBS_Volume: Gollum is a simple wiki system built on top of Git that powers GitHub Wikis. This template installs a Gollum Wiki stack on a single EC2 instance with an EBS volume for storage and demonstrates using the AWS CloudFormation bootstrap scripts to install the packages and files necessary at instance launch time. **WARNING** This template creates an Amazon EC2 instance and an EBS volume. You will be billed for the AWS resources used if you create a stack from this template.")
  AWSTemplateFormatVersion("2010-09-09")

  Parameter("KeyName") do
    Description("Name of an existing EC2 KeyPair to enable SSH access to the instances")
    Type("String")
    AllowedPattern("[-_ a-zA-Z0-9]*")
    MaxLength(64)
    MinLength(1)
    ConstraintDescription("can contain only alphanumeric characters, spaces, dashes and underscores.")
  end

  Parameter("VolumeSize") do
    Description("WebServer EC2 instance type")
    Type("Number")
    Default("5")
    MaxValue(1024)
    MinValue(5)
    ConstraintDescription("must be between 5 and 1024 Gb.")
  end

  Parameter("InstanceType") do
    Description("WebServer EC2 instance type")
    Type("String")
    Default("m1.small")
    AllowedValues([
  "t1.micro",
  "m1.small",
  "m1.medium",
  "m1.large",
  "m1.xlarge",
  "m2.xlarge",
  "m2.2xlarge",
  "m2.4xlarge",
  "m3.xlarge",
  "m3.2xlarge",
  "c1.medium",
  "c1.xlarge",
  "cc1.4xlarge",
  "cc2.8xlarge",
  "cg1.4xlarge"
])
    ConstraintDescription("must be a valid EC2 instance type.")
  end

  Parameter("SSHLocation") do
    Description("The IP address range that can be used to SSH to the EC2 instances")
    Type("String")
    Default("0.0.0.0/0")
    AllowedPattern("(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})/(\\d{1,2})")
    MaxLength(18)
    MinLength(9)
    ConstraintDescription("must be a valid IP CIDR range of the form x.x.x.x/x.")
  end

  Mapping("AWSInstanceType2Arch", {
  "c1.medium"   => {
    "Arch" => "64"
  },
  "c1.xlarge"   => {
    "Arch" => "64"
  },
  "cc1.4xlarge" => {
    "Arch" => "64HVM"
  },
  "cc2.8xlarge" => {
    "Arch" => "64HVM"
  },
  "cg1.4xlarge" => {
    "Arch" => "64HVM"
  },
  "m1.large"    => {
    "Arch" => "64"
  },
  "m1.medium"   => {
    "Arch" => "64"
  },
  "m1.small"    => {
    "Arch" => "64"
  },
  "m1.xlarge"   => {
    "Arch" => "64"
  },
  "m2.2xlarge"  => {
    "Arch" => "64"
  },
  "m2.4xlarge"  => {
    "Arch" => "64"
  },
  "m2.xlarge"   => {
    "Arch" => "64"
  },
  "m3.2xlarge"  => {
    "Arch" => "64"
  },
  "m3.xlarge"   => {
    "Arch" => "64"
  },
  "t1.micro"    => {
    "Arch" => "64"
  }
})

  Mapping("AWSRegionArch2AMI", {
  "ap-northeast-1" => {
    "32"    => "ami-0644f007",
    "64"    => "ami-0a44f00b",
    "64HVM" => "NOT_YET_SUPPORTED"
  },
  "ap-southeast-1" => {
    "32"    => "ami-b4b0cae6",
    "64"    => "ami-beb0caec",
    "64HVM" => "NOT_YET_SUPPORTED"
  },
  "ap-southeast-2" => {
    "32"    => "ami-b3990e89",
    "64"    => "ami-bd990e87",
    "64HVM" => "NOT_YET_SUPPORTED"
  },
  "eu-west-1"      => {
    "32"    => "ami-973b06e3",
    "64"    => "ami-953b06e1",
    "64HVM" => "NOT_YET_SUPPORTED"
  },
  "sa-east-1"      => {
    "32"    => "ami-3e3be423",
    "64"    => "ami-3c3be421",
    "64HVM" => "NOT_YET_SUPPORTED"
  },
  "us-east-1"      => {
    "32"    => "ami-31814f58",
    "64"    => "ami-1b814f72",
    "64HVM" => "ami-0da96764"
  },
  "us-west-1"      => {
    "32"    => "ami-11d68a54",
    "64"    => "ami-1bd68a5e",
    "64HVM" => "NOT_YET_SUPPORTED"
  },
  "us-west-2"      => {
    "32"    => "ami-38fe7308",
    "64"    => "ami-30fe7300",
    "64HVM" => "NOT_YET_SUPPORTED"
  }
})

  Resource("WebServer") do
    Type("AWS::EC2::Instance")
    Metadata("AWS::CloudFormation::Init", {
  "config" => {
    "packages" => {
      "rubygems" => {
        "gollum"    => [],
        "nokogiri"  => [],
        "rdiscount" => []
      },
      "yum"      => {
        "gcc"           => [],
        "git"           => [],
        "libxml2-devel" => [],
        "libxslt-devel" => [],
        "make"          => [],
        "ruby-devel"    => [],
        "ruby-rdoc"     => [],
        "rubygems"      => []
      }
    }
  }
})
    Property("ImageId", FnFindInMap("AWSRegionArch2AMI", Ref("AWS::Region"), FnFindInMap("AWSInstanceType2Arch", Ref("InstanceType"), "Arch")))
    Property("InstanceType", Ref("InstanceType"))
    Property("SecurityGroups", [
  Ref("WebServerSecurityGroup")
])
    Property("KeyName", Ref("KeyName"))
    Property("UserData", FnBase64(FnJoin("", [
  "#!/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::StackId"),
  " -r WebServer ",
  "    --region ",
  Ref("AWS::Region"),
  " || error_exit 'Failed to run cfn-init'\n",
  "# Wait for the EBS volume to show up\n",
  "while [ ! -e /dev/sdh ]; do echo Waiting for EBS volume to attach; sleep 5; done\n",
  "# Format the EBS volume and mount it\n",
  "mkdir /var/wikidata\n",
  "/sbin/mkfs -t ext3 /dev/sdh1\n",
  "mount /dev/sdh1 /var/wikidata\n",
  "# Initialize the wiki and fire up the server\n",
  "cd /var/wikidata\n",
  "git init\n",
  "gollum --port 80 --host 0.0.0.0 &\n",
  "# If all is well so signal success\n",
  "/opt/aws/bin/cfn-signal -e $? -r \"Rails application setup complete\" '",
  Ref("WaitHandle"),
  "'\n"
])))
  end

  Resource("WebServerSecurityGroup") do
    Type("AWS::EC2::SecurityGroup")
    Property("GroupDescription", "Enable SSH access and HTTP access on the inbound port")
    Property("SecurityGroupIngress", [
  {
    "CidrIp"     => "0.0.0.0/0",
    "FromPort"   => "80",
    "IpProtocol" => "tcp",
    "ToPort"     => "80"
  },
  {
    "CidrIp"     => Ref("SSHLocation"),
    "FromPort"   => "22",
    "IpProtocol" => "tcp",
    "ToPort"     => "22"
  }
])
  end

  Resource("DataVolume") do
    Type("AWS::EC2::Volume")
    Property("Size", Ref("VolumeSize"))
    Property("AvailabilityZone", FnGetAtt("WebServer", "AvailabilityZone"))
    Property("Tags", [
  {
    "Key"   => "Usage",
    "Value" => "Gollum Data Volume"
  }
])
  end

  Resource("MountPoint") do
    Type("AWS::EC2::VolumeAttachment")
    Property("InstanceId", Ref("WebServer"))
    Property("VolumeId", Ref("DataVolume"))
    Property("Device", "/dev/sdh")
  end

  Resource("WaitHandle") do
    Type("AWS::CloudFormation::WaitConditionHandle")
  end

  Resource("WaitCondition") do
    Type("AWS::CloudFormation::WaitCondition")
    Metadata("Comment1", "Note that the WaitCondition is dependent on the volume mount point allowing the volume to be created and attached to the EC2 instance")
    Metadata("Comment2", "The instance bootstrap script waits for the volume to be attached to the instance prior to installing Gollum and signalling completion")
    DependsOn("MountPoint")
    Property("Handle", Ref("WaitHandle"))
    Property("Timeout", "300")
  end

  Output("WebsiteURL") do
    Description("URL for Gollum wiki")
    Value(FnJoin("", [
  "http://",
  FnGetAtt("WebServer", "PublicDnsName")
]))
  end
end
