Kubernetes EC2 Autoscaling with FastAPI on Kubernetes

📚 Project Overview

This project demonstrates Infrastructure as Code (IaC) to deploy Kubernetes worker nodes on AWS EC2 instances using Terraform, Ansible, Docker, and Kubernetes. It also deploys a sample FastAPI application inside Kubernetes automatically.

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🛠 How to Run

1. Prerequisites

• AWS Account
• IAM User with EC2 permissions
• Terraform (>= 1.7.0)
• Ansible (9.3.0)
• Python3 environment
• SSH Key Pair for EC2 access

2. Setup

git clone https://github.com/Vrana710/k8s-ec2-autoscaling-demo.git
cd k8s-ec2-autoscaling

Install requirements:

pip install -r requirements.txt

3. Provision EC2 Instance

cd infrastructure/terraform
terraform init
terraform apply -auto-approve

Get the Public IP from output.

4. Configure Ansible Inventory

Edit config/inventory.ini:

[all]
<public_ip> ansible_user=ubuntu ansible_ssh_private_key_file=../your_key_name.pem

5. Configure EC2 Server

cd infrastructure/ansible
ansible-playbook playbook.yml -i ../../config/inventory.ini

This installs Docker, Kubernetes components, and CloudWatch agent.

6. Initialize Kubernetes Cluster

SSH into EC2:

ssh -i ../your_key_name.pem ubuntu@<public_ip>

Initialize Kubernetes:

sudo kubeadm init --pod-network-cidr=10.244.0.0/16
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Install Flannel CNI:

kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

7. Build FastAPI Docker Image

cd ~/app
sudo docker build -t fastapi-app:latest .

8. Deploy FastAPI App to Kubernetes

kubectl apply -f app/deployment.yaml

Check deployment:

kubectl get pods
kubectl get svc

Access FastAPI app via public IP.

9. Monitor and Scale

Monitor CPU manually:

bash scripts/monitor_and_scale.sh

If CPU exceeds threshold, new nodes are provisioned.

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🎯 Outcome

• Fully provisioned EC2 instance
• Configured Kubernetes + CloudWatch
• FastAPI app deployed inside Kubernetes
• Ready for manual or automatic scaling
• GitHub Actions pipeline ready for full automation

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📈 Architecture Diagram

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📦 Project Structure

k8s-ec2-autoscaling/
├── app/
│   ├── main.py
│   ├── Dockerfile
│   └── deployment.yaml
├── config/
│   ├── inventory.ini
│   └── terraform.tfvars (with updated values)
├── infrastructure/
│   ├── terraform/
│   └── ansible/
├── scripts/
│   └── monitor_and_scale.sh
├── .github/workflows/deploy.yml
├── requirements.txt
└── docs/
    └── README.md

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⚙️ Terraform Variable Configuration

Edit config/terraform.tfvars:

region = "your name of region"
ami_id = "your ami id"
key_name = "your key name"
instance_type = "your instance type"

Important: Key name is the AWS EC2 Key Pair name (without .pem).

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🛡️ Security

• SSH via key-pair only
• Minimum necessary ports open (22, 80)
• Terraform-managed security groups
• CloudWatch Agent installed for monitoring

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