Introduction to Automatic Resource Allocation on AWS

As businesses embrace cloud computing, managing web traffic efficiently becomes essential. AWS Auto Scaling is a robust solution that dynamically adjusts your resources to maintain optimal application performance while minimizing costs. This automated resource allocation ensures that your infrastructure can handle varying workloads seamlessly.

In this blog post, we’ll explore how to implement Auto Scaling on AWS using Ansible, a robust IT automation tool. This guide will walk you through every step, from setting up AWS for Auto Scaling to deploying scaling policies and monitoring performance with CloudWatch.

Why Auto Scaling is Crucial for Web Traffic Management

Web traffic is unpredictable—an e-commerce site might see a spike during sales, while a blog might experience sudden surges due to viral content. Auto Scaling helps address these challenges by:

  • Ensuring High Availability: Automatically adding or removing instances ensures your application is always available.
  • Optimizing Costs: Eliminates the need to overprovision resources by scaling only when necessary.
  • Improving Performance: Ensures sufficient capacity during peak traffic, avoiding performance bottlenecks.

With Auto Scaling, businesses can deliver consistent user experiences without the stress of manual intervention.

Setting Up AWS for Auto Scaling with EC2 Classic

To begin, you’ll need to configure your AWS environment for Auto Scaling:

  1. Create a Launch Template: Define the configuration for EC2 instances, including the AMI, instance type, key pair, and security groups.
  2. Configure an Auto Scaling Group: Specify the minimum, desired, and maximum number of instances, as well as associated subnets and load balancers.
  3. Set Up Elastic Load Balancing (ELB): Distribute incoming traffic across instances in multiple availability zones.

Configuring Ansible for AWS Integration

Ansible simplifies the deployment and management of AWS resources with its AWS modules. Follow these steps to configure Ansible:

  1. Install Required Libraries: Ensure boto3 and botocore Python libraries are installed.
    pip install boto3 botocore
  2. Set Up AWS Credentials: Configure AWS access keys in ~/.aws/credentials or use environment variables.
  3. Update Ansible Configuration: Define AWS regions and settings in your Ansible playbooks.

Deploying Auto Scaling Groups and Load Balancers with Ansible Playbooks

Here’s how to deploy an Auto Scaling setup using Ansible:

  1. Define a Playbook for Launch Template Creation:
    – name: Create Launch Template

  ec2_launch_template:

    name: my-launch-template

    image_id: ami-12345678

    instance_type: t2.micro

    key_name: my-key

    security_groups:

      – my-security-group

    region: us-east-1

  register: launch_template

  1. Create an Auto Scaling Group:
    – name: Create Auto Scaling Group

  ec2_asg:

    name: my-auto-scaling-group

    launch_template: “{{ launch_template.template_id }}”

    min_size: 1

    max_size: 5

    desired_capacity: 2

    vpc_zone_identifier: subnet-abc123,subnet-def456

    region: us-east-1

  1. Integrate with an ELB:
    – name: Attach Load Balancer to Auto Scaling Group

  ec2_asg_lifecycle_hook:

    name: my-auto-scaling-group

    load_balancers: 

      – my-load-balancer

    region: us-east-1

Implementing Scaling Policies and Monitoring with CloudWatch Metrics

To optimize scaling, define scaling policies based on CloudWatch metrics:

  1. Create Scaling Policies:

– name: Create Scaling Policies

  ec2_scaling_policy:

    asg_name: my-auto-scaling-group

    policy_name: scale-up

    adjustment_type: ChangeInCapacity

    scaling_adjustment: 1

    cooldown: 300

    metric_aggregation_type: Average

    region: us-east-1

  1. Set Up CloudWatch Alarms: Configure alarms to trigger scaling actions based on metrics such as CPU utilization:
    – name: Create CloudWatch Alarm

  cloudwatch_alarm:

    name: high-cpu-utilization

    metric: CPUUtilization

    namespace: AWS/EC2

    statistic: Average

    comparison: “>=”

    threshold: 70

    period: 300

    evaluation_periods: 2

    alarm_actions:

      – arn:aws:autoscaling:region:account-id:scalingPolicy:policy-id:autoScalingGroupName/group-name

    region: us-east-1

Conclusion

By combining the power of AWS Auto Scaling with Ansible’s automation capabilities, you can create a scalable and resilient infrastructure that adapts to your workload. This approach simplifies resource management and ensures cost efficiency and high availability.

References

Automate Ansible playbook deployment with Amazon EC2 and GitHub

Keeping Ansible effortless with AWS Systems Manager