HeatTemplateFormatVersion: '2012-12-12'
Description: AWS CloudFormation Sample Template
Parameters:
  KeyName: {Description: Name of an existing EC2 KeyPair
      to enable SSH access to the instances, Type: String}
  InstanceType:
    Description: WebServer EC2 instance type
    Type: String
    Default: m1.small
    AllowedValues: [m1.tiny, m1.small, m1.medium, m1.large, m1.xlarge]
    ConstraintDescription: must be a valid EC2 instance type.
  DBName: {Default: wordpress, Description: The
      WordPress 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: {Default: admin, NoEcho: 'true',
    Description: The WordPress 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: {Default: admin, NoEcho: 'true',
    Description: The WordPress database admin account password, Type: String,
    MinLength: '1', MaxLength: '41', AllowedPattern: '[a-zA-Z0-9]*',
    ConstraintDescription: must contain only alphanumeric characters.}
  DBRootPassword: {Default: admin, NoEcho: 'true',
    Description: Root password for MySQL, Type: String,
    MinLength: '1', MaxLength: '41', AllowedPattern: '[a-zA-Z0-9]*',
    ConstraintDescription: must contain only alphanumeric characters.}
  LinuxDistribution:
    Default: F17
    Description: Distribution of choice
    Type: String
    AllowedValues: [F18, F17, U10, RHEL-6.1, RHEL-6.2, RHEL-6.3]
Mappings:
  AWSInstanceType2Arch:
    m1.tiny: {Arch: '32'}
    m1.small: {Arch: '64'}
    m1.medium: {Arch: '64'}
    m1.large: {Arch: '64'}
    m1.xlarge: {Arch: '64'}
  DistroArch2AMI:
    F18: {'32': F18-i386-cfntools, '64': F18-x86_64-cfntools}
    F17: {'32': F17-i386-cfntools, '64': F17-x86_64-cfntools}
    U10: {'32': U10-i386-cfntools, '64': U10-x86_64-cfntools}
    RHEL-6.1: {'32': rhel61-i386-cfntools, '64': rhel61-x86_64-cfntools}
    RHEL-6.2: {'32': rhel62-i386-cfntools, '64': rhel62-x86_64-cfntools}
    RHEL-6.3: {'32': rhel63-i386-cfntools, '64': rhel63-x86_64-cfntools}
Resources:
  CfnUser: {Type: 'AWS::IAM::User'}
  WebServerKeys:
    Type: AWS::IAM::AccessKey
    Properties:
      UserName: {Ref: CfnUser}
  WebServerGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Properties:
      AvailabilityZones: {'Fn::GetAZs': ''}
      LaunchConfigurationName: {Ref: LaunchConfig}
      MinSize: '1'
      MaxSize: '3'
      LoadBalancerNames:
      - {Ref: ElasticLoadBalancer}
  WebServerScaleUpPolicy:
    Type: AWS::AutoScaling::ScalingPolicy
    Properties:
      AdjustmentType: ChangeInCapacity
      AutoScalingGroupName: {Ref: WebServerGroup}
      Cooldown: '60'
      ScalingAdjustment: '1'
  WebServerScaleDownPolicy:
    Type: AWS::AutoScaling::ScalingPolicy
    Properties:
      AdjustmentType: ChangeInCapacity
      AutoScalingGroupName: {Ref: WebServerGroup}
      Cooldown: '60'
      ScalingAdjustment: '-1'
  MEMAlarmHigh:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Scale-up if MEM > 50% for 1 minute
      MetricName: MemoryUtilization
      Namespace: system/linux
      Statistic: Average
      Period: '60'
      EvaluationPeriods: '1'
      Threshold: '50'
      AlarmActions:
      - {Ref: WebServerScaleUpPolicy}
      Dimensions:
      - Name: AutoScalingGroupName
        Value: {Ref: WebServerGroup}
      ComparisonOperator: GreaterThanThreshold
  MEMAlarmLow:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Scale-down if MEM < 15% for 1 minute
      MetricName: MemoryUtilization
      Namespace: system/linux
      Statistic: Average
      Period: '60'
      EvaluationPeriods: '1'
      Threshold: '15'
      AlarmActions:
      - {Ref: WebServerScaleDownPolicy}
      Dimensions:
      - Name: AutoScalingGroupName
        Value: {Ref: WebServerGroup}
      ComparisonOperator: LessThanThreshold
  ElasticLoadBalancer:
    Type: AWS::ElasticLoadBalancing::LoadBalancer
    Properties:
      AvailabilityZones: {'Fn::GetAZs': ''}
      Listeners:
      - {LoadBalancerPort: '80', InstancePort: '80',
        Protocol: HTTP}
      HealthCheck: {Target: 'HTTP:80/', HealthyThreshold: '3',
        UnhealthyThreshold: '5', Interval: '30', Timeout: '5'}
  LaunchConfig:
    Type: AWS::AutoScaling::LaunchConfiguration
    Metadata:
      AWS::CloudFormation::Init:
        config:
          files:
            /etc/cfn/cfn-credentials:
              content:
                Fn::Join:
                - ''
                - - AWSAccessKeyId=
                  - {Ref: WebServerKeys}
                  - '

                    '
                  - AWSSecretKey=
                  - Fn::GetAtt: [WebServerKeys, SecretAccessKey]
                  - '

                    '
              mode: '000400'
              owner: root
              group: root
            /tmp/setup.mysql:
              content:
                Fn::Join:
                - ''
                - - 'CREATE DATABASE '
                  - {Ref: DBName}
                  - ';

                    '
                  - 'GRANT ALL PRIVILEGES ON '
                  - {Ref: DBName}
                  - .* TO '
                  - {Ref: DBUsername}
                  - '''@''localhost''

                    '
                  - IDENTIFIED BY '
                  - {Ref: DBPassword}
                  - ''';

                    '
                  - 'FLUSH PRIVILEGES;

                    '
                  - 'EXIT

                    '
              mode: '000644'
              owner: root
              group: root
            /tmp/stats-crontab.txt:
              content:
                Fn::Join:
                - ''
                - - 'MAIL=""

                    '
                  - '

                    '
                  - '* * * * * /opt/aws/bin/cfn-push-stats --watch '
                  - {Ref: MEMAlarmHigh}
                  - ' --mem-util

                    '
                  - '* * * * * /opt/aws/bin/cfn-push-stats --watch '
                  - {Ref: MEMAlarmLow}
                  - ' --mem-util

                    '
              mode: '000600'
              owner: root
              group: root
          packages:
            yum:
              python-psutil: []
              cronie: []
              mysql: []
              mysql-server: []
              httpd: []
              wordpress: []
          services:
            systemd:
              mysqld: {enabled: 'true', ensureRunning: 'true'}
              httpd: {enabled: 'true', ensureRunning: 'true'}
              crond: {enabled: 'true', ensureRunning: 'true'}
    Properties:
      ImageId:
        Fn::FindInMap:
        - DistroArch2AMI
        - {Ref: LinuxDistribution}
        - Fn::FindInMap:
          - AWSInstanceType2Arch
          - {Ref: InstanceType}
          - Arch
      InstanceType: {Ref: InstanceType}
      KeyName: {Ref: KeyName}
      UserData:
        Fn::Base64:
          Fn::Join:
          - ''
          - - '#!/bin/bash -v

              '
            - '/opt/aws/bin/cfn-init -s '
            - {Ref: 'AWS::StackName'}
            - ' -r LaunchConfig '
            - ' --region '
            - {Ref: 'AWS::Region'}
            - '

              '
            - '# Setup MySQL root password and create a user

              '
            - mysqladmin -u root password '
            - {Ref: DBRootPassword}
            - '''

              '
            - mysql -u root --password='
            - {Ref: DBRootPassword}
            - ''' < /tmp/setup.mysql

              '
            - 'sed -i "/Deny from All/d" /etc/httpd/conf.d/wordpress.conf

              '
            - sed --in-place --e s/database_name_here/
            - {Ref: DBName}
            - / --e s/username_here/
            - {Ref: DBUsername}
            - / --e s/password_here/
            - {Ref: DBPassword}
            - '/ /usr/share/wordpress/wp-config.php

              '
            - 'systemctl restart httpd.service

              '
            - '# install crontab

              '
            - 'crontab /tmp/stats-crontab.txt

              '
Outputs:
  URL:
    Description: The URL of the website
    Value:
      Fn::Join:
      - ''
      - - http://
        - Fn::GetAtt: [ElasticLoadBalancer, DNSName]
        - /wordpress