heat_template_version: 2013-05-23

description: AutoScaling Wordpress
parameters:
  image:
    type: string
    description: Image used for servers
    default: 7f4bdc18-cb48-46b5-8d9c-6cabaa4270d6
  key:
    type: string
    description: SSH key to connect to the servers
    default: mykey
  flavor:
    type: string
    description: flavor used by the web servers
    default: m1.small
  database_flavor:
    type: string
    description: flavor used by the db server
    default: m1.small
  subnet_id:
    type: string
    description: subnet on which the load balancer will be located
    default: 99baadc0-a4c5-4141-b201-aba51e6ac586
  database_name:
    type: string
    description: Name of the wordpress DB
    default: wordpress
  database_user:
    type: string
    description: Name of the wordpress user
    default: wordpress
  public_net_id:
    type: string
    description: >
      ID of public network for which floating IP addresses will be allocated
    default: 3a72a0a0-156a-4650-934b-13f29587969a
  private_net_id:
    type: string
    description: ID of private network into which servers get deployed
    default: 1e2e0ea5-3f85-435a-af8d-93f377d52560
resources:
  database_password:
    type: OS::Heat::RandomString
  database_root_password:
    type: OS::Heat::RandomString
  db:
    type: OS::Nova::Server
    properties:
      name: Server1
      image: { get_param: image }
      flavor: { get_param: flavor }
      key_name: { get_param: key }
      networks:
        - port: { get_resource: server1_port }
      user_data_format: RAW
      config_drive: "true"
      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: My::lb::Server
        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: 5
      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}

  server1_port:
    type: OS::Neutron::Port
    properties:
      network_id: { get_param: private_net_id }
      fixed_ips:
        - subnet_id: { get_param: subnet_id }
      security_groups: [{ get_resource: server_security_group }]

  server1_floating_ip:
    type: OS::Neutron::FloatingIP
    properties:
      floating_network_id: { get_param: public_net_id }
      port_id: { get_resource: server1_port }

  server_security_group:
    type: OS::Neutron::SecurityGroup
    properties:
      description: Add security group rules for server
      name: security-group
      rules:
        - remote_ip_prefix: 0.0.0.0/0
          protocol: tcp
          port_range_min: 22
          port_range_max: 22
        - remote_ip_prefix: 0.0.0.0/0


          protocol: icmp
outputs:
  server1_private_ip:
    description: IP address of server1 in private network
    value: { get_attr: [ server1, first_address ] }
  server1_public_ip:
    description: Floating IP address of server1 in public network
    value: { get_attr: [ server1_floating_ip, floating_ip_address ] }
  scale_up_url:
    description: >
      This URL is the webhook to scale up the autoscaling group.  You
      can invoke the scale-up operation by doing an HTTP POST to this
      URL; no body nor extra headers are needed.
    value: {get_attr: [web_server_scaleup_policy, alarm_url]}
  scale_dn_url:
    description: >
      This URL is the webhook to scale down the autoscaling group.
      You can invoke the scale-down operation by doing an HTTP POST to
      this URL; no body nor extra headers are needed.
    value: {get_attr: [web_server_scaledown_policy, alarm_url]}
  pool_ip_address:
    value: {get_attr: [pool, vip, address]}
    description: The IP address of the load balancing pool
  ceilometer_query:
    value:
      str_replace:
        template: >
          ceilometer statistics -m cpu_util
          -q metadata.user_metadata.stack=stackval -p 600 -a avg
        params:
          stackval: { get_param: "OS::stack_id" }
    description: >
      This is a Ceilometer query for statistics on the cpu_util meter
      Samples about OS::Nova::Server instances in this stack.  The -q
      parameter selects Samples according to the subject's metadata.
      When a VM's metadata includes an item of the form metering.X=Y,
      the corresponding Ceilometer resource has a metadata item of the
      form user_metadata.X=Y and samples about resources so tagged can
      be queried with a Ceilometer query term of the form
      metadata.user_metadata.X=Y.  In this case the nested stacks give
      their VMs metadata that is passed as a nested stack parameter,
      and this stack passes a metadata of the form metering.stack=Y,
      where Y is this stack's ID.