autoscale-ansible

#
# Ansible playbook definition for APP layer deployment.
# It deploys 4-to-6 APP servers, in different AZ
# All needed variables in "vars" section
# Reynaldo R. Martinez P.
# E-Mail tigerlinux at gmail dot com
#
#
---
- name: Create APP layer
  hosts: localhost
  gather_facts: False
  vars:
    vpc_region: us-west-2
    sec_group: sg-ea0d3993
    key_name: tigerlinux-01
    amazon_image: ami-a9d276c9
    subnet_p1: subnet-f1b12294
    subnet_p2: subnet-b34591ea
    machine_type: t2.micro
    az_p1: us-west-2a
    az_p2: us-west-2c
  tasks:
  - name: app layer launch configuration
    ec2_lc:
      name: app_lc
      image_id: "{{ amazon_image }}"
      key_name: "{{ key_name }}"
      region: "{{ vpc_region }}"
      security_groups: "{{ sec_group }}"
      instance_type: "{{ machine_type }}"
      assign_public_ip: yes
      instance_monitoring: yes
      user_data: |
                  #!/bin/bash
                  DEBIAN_FRONTEND=noninteractive apt-get update
                  DEBIAN_FRONTEND=noninteractive apt-get -y install apache2
                  hostname > /var/www/html/index.html
                  systemctl restart apache2
                  systemctl enable apache

  - name: Auto Scaling Group
    ec2_asg:
      name: app_asg
      availability_zones:
         - "{{ az_p1 }}"
         - "{{ az_p2 }}"
      launch_config_name: app_lc
      tags:
        - environment: devel
        - applayer: webapps
      min_size: 4
      max_size: 6
      desired_capacity: 4
      vpc_zone_identifier:
        - "{{ subnet_p1 }}"
        - "{{ subnet_p2 }}"
      region: "{{ vpc_region }}"

  - name: Scaling Policies
    ec2_scaling_policy:
      region: "{{ vpc_region }}"
      name: "{{ item.name }}"
      asg_name: app_asg
      state: present
      adjustment_type: "{{ item.adjustment_type }}"
      min_adjustment_step: "{{ item.min_adjustment_step }}"
      scaling_adjustment: "{{ item.scaling_adjustment }}"
      cooldown: "{{ item.cooldown }}"
    with_items:
      - name: "Increase Group Size"
        adjustment_type: "ChangeInCapacity"
        scaling_adjustment: +1
        min_adjustment_step: 1
        cooldown: 180
      - name: "Decrease Group Size"
        adjustment_type: "ChangeInCapacity"
        scaling_adjustment: -1
        min_adjustment_step: 1
        cooldown: 300
    register: sp_app_asg_result

  - name: Set cloudwatch ScaleUp alarm and relate them to proper Scaling Policy
    ec2_metric_alarm:
      region: "{{ vpc_region }}"
      name: pp_asg-ScaleUp
      state: present
      metric: "CPUUtilization"
      namespace: "AWS/EC2"
      statistic: "Average"
      comparison: ">="
      threshold: 80
      period: 60
      evaluation_periods: 2
      unit: "Percent"
      dimensions:
        AutoScalingGroupName: app_asg
      alarm_actions:
        - "{{ sp_app_asg_result.results[0].arn }}"

  - name: Set cloudwatch ScaleDown alarm and relate them to proper Scaling Policy
    ec2_metric_alarm:
      region: "{{ vpc_region }}"
      name: pp_asg-ScaleDown
      state: present
      metric: "CPUUtilization"
      namespace: "AWS/EC2"
      statistic: "Average"
      comparison: "<="
      threshold: 15
      period: 60
      evaluation_periods: 4
      unit: "Percent"
      dimensions:
        AutoScalingGroupName: app_asg
      alarm_actions:
        - "{{ sp_app_asg_result.results[1].arn }}"