heat-templates/hot/autoscaling.yaml

heat_template_version: 2013-05-23
description: AutoScaling Wordpress
parameters:
  image:
    type: string
    description: Image used for servers
  key:
    type: string
    description: SSH key to connect to the servers
  flavor:
    type: string
    description: flavor used by the web servers
  database_flavor:
    type: string
    description: flavor used by the db server
  subnet_id:
    type: string
    description: subnet on which the load balancer will be located
  database_name:
    type: string
    description: Name of the wordpress DB
    default: wordpress
  database_user:
    type: string
    description: Name of the wordpress user
    default: wordpress
resources:
  database_password:
    type: OS::Heat::RandomString
  database_root_password:
    type: OS::Heat::RandomString
  db:
    type: OS::Nova::Server
    properties:
      flavor: {get_param: database_flavor}
      image: {get_param: image}
      key_name: {get_param: key}
      user_data_format: RAW
      user_data:
        str_replace:
          template: |
            #!/bin/bash -v
            yum -y install mariadb mariadb-server
            systemctl enable mariadb.service
            systemctl start mariadb.service
            mysqladmin -u root password $db_rootpassword
            cat << EOF | mysql -u root --password=$db_rootpassword
            CREATE DATABASE $db_name;
            GRANT ALL PRIVILEGES ON $db_name.* TO "$db_user"@"%"
            IDENTIFIED BY "$db_password";
            FLUSH PRIVILEGES;
            EXIT
            EOF            
          params:
            $db_rootpassword: {get_attr: [database_root_password, value]}
            $db_name: {get_param: database_name}
            $db_user: {get_param: database_user}
            $db_password: {get_attr: [database_password, value]}
  web_server_group:
    type: OS::Heat::AutoScalingGroup
    properties:
      min_size: 1
      max_size: 3
      resource:
        type: lb_server.yaml
        properties:
          flavor: {get_param: flavor}
          image: {get_param: image}
          key_name: {get_param: key}
          pool_id: {get_resource: pool}
          metadata: {"metering.stack": {get_param: "OS::stack_id"}}
          user_data:
            str_replace:
              template: |
                #!/bin/bash -v
                yum -y install httpd wordpress
                systemctl enable httpd.service
                systemctl start httpd.service
                setsebool -P httpd_can_network_connect_db=1

                sed -i "/Deny from All/d" /etc/httpd/conf.d/wordpress.conf
                sed -i "s/Require local/Require all granted/" /etc/httpd/conf.d/wordpress.conf
                sed -i s/database_name_here/$db_name/ /etc/wordpress/wp-config.php
                sed -i s/username_here/$db_user/ /etc/wordpress/wp-config.php
                sed -i s/password_here/$db_password/ /etc/wordpress/wp-config.php
                sed -i s/localhost/$db_host/ /etc/wordpress/wp-config.php

                systemctl restart httpd.service                
              params:
                $db_name: {get_param: database_name}
                $db_user: {get_param: database_user}
                $db_password: {get_attr: [database_password, value]}
                $db_host: {get_attr: [db, first_address]}
  web_server_scaleup_policy:
    type: OS::Heat::ScalingPolicy
    properties:
      adjustment_type: change_in_capacity
      auto_scaling_group_id: {get_resource: web_server_group}
      cooldown: 60
      scaling_adjustment: 1
  web_server_scaledown_policy:
    type: OS::Heat::ScalingPolicy
    properties:
      adjustment_type: change_in_capacity
      auto_scaling_group_id: {get_resource: web_server_group}
      cooldown: 60
      scaling_adjustment: -1
  cpu_alarm_high:
    type: OS::Ceilometer::Alarm
    properties:
      description: Scale-up if the average CPU > 50% for 1 minute
      meter_name: cpu_util
      statistic: avg
      period: 60
      evaluation_periods: 1
      threshold: 50
      alarm_actions:
        - {get_attr: [web_server_scaleup_policy, alarm_url]}
      matching_metadata: {'metadata.user_metadata.stack': {get_param: "OS::stack_id"}}
      comparison_operator: gt
  cpu_alarm_low:
    type: OS::Ceilometer::Alarm
    properties:
      description: Scale-down if the average CPU < 15% for 10 minutes
      meter_name: cpu_util
      statistic: avg
      period: 600
      evaluation_periods: 1
      threshold: 15
      alarm_actions:
        - {get_attr: [web_server_scaledown_policy, alarm_url]}
      matching_metadata: {'metadata.user_metadata.stack': {get_param: "OS::stack_id"}}
      comparison_operator: lt
  monitor:
    type: OS::Neutron::HealthMonitor
    properties:
      type: TCP
      delay: 3
      max_retries: 5
      timeout: 5
  pool:
    type: OS::Neutron::Pool
    properties:
      protocol: HTTP
      monitors: [{get_resource: monitor}]
      subnet_id: {get_param: subnet_id}
      lb_method: ROUND_ROBIN
      vip:
        protocol_port: 80
  lb:
    type: OS::Neutron::LoadBalancer
    properties:
      protocol_port: 80
      pool_id: {get_resource: pool}