Tech Stack used in this Project

Rust App that calculates the Fibonacci sequence and deploys it to Kubernetes

Tip

• This project provides various implementations of the Fibonacci sequence in Rust, including recursive, memoized, iterative, and dynamic programming approaches.
• It also includes a Kubernetes deployment with Helm charts deploying to minikube.
• Cluster has also Prometheus and Grafana installed to monitor the application.

Tip

The Fibonacci sequence is a series of numbers in which each number is the sum of the two preceding ones, usually starting with 0 and 1.

Tip

The sequence starts: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...

Tip

The Fibonacci sequence is defined by the recurrence relation: F(n) = F(n-1) + F(n-2) with base cases F(0) = 0 and F(1) = 1.

Tip

The Fibonacci sequence grows exponentially, so the recursive implementation is not efficient for large values of n.

Tip

The iterative and dynamic programming implementations are more efficient for large values of n.

Tip

The memoized recursive implementation is more efficient than the simple recursive implementation because it avoids redundant calculations.

Tip

The pattern matching implementation is similar to the simple recursive implementation but uses pattern matching instead of if-else statements.

Tip

The dynamic programming implementation uses an array to store the Fibonacci numbers and avoids redundant calculations.

The following implementations are provided:

• fibonacci: A simple recursive implementation.
• fibonacci_match: A recursive implementation using pattern matching.
• fibonacci_dp: An implementation using dynamic programming.
• fibonacci_memo: A memoized recursive implementation.
• fibonacci_iterative: An iterative implementation.

Prerequisites

Important

Before you begin, ensure you have the following tools installed:

1. Rust & Cargo (for local builds/verification, optional if you only build in Docker).
2. Docker (to build and push container images).
3. Helm (to manage Kubernetes deployments).
4. Minikube or a Kubernetes Cluster (for testing).
5. Docker Hub Account (to push container images).

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1. Building the Docker Image

Tip

You can build the Docker image using the provided Dockerfile Tag the image after its building Using your username login to Docker Hub and push the image to Docker Hub.

docker login --username ${DOCKER_USERNAME}
docker build -t fibonacci_rust:latest .
docker tag fibonacci_rust:latest ${DOCKER_USERNAME}/fibonacci_rust:${DOCKER_TAG}
docker push ${DOCKER_USERNAME}/fibonacci_rust:${DOCKER_TAG}

1. Deploying the Application to Kubernetes via Terraform

Tip

This repository includes a simple Terraform module (in the terraform/ directory) that deploys the fibonacci container into Kubernetes. The key files are:

• main.tf – Terraform configuration.

1.1 Deploy the Application

Tip

Navigate to the terraform/ directory and run the following commands to deploy the application:

terraform init

terraform validate

terraform apply -var="docker_username=your_docker_username" -var="docker_image_tag=your_docker_image_tag"

• Once all resources are deployed you can start the minikube service to access the application.

minikube service fibonacci-service

• You can go to this section to see about monitoring 2.5 Monitoring the Application with Prometheus and Grafana

2. Deploying the Application to Kubernetes

2.1 Deploy via Helm Charts - Helm Chart Overview

Tip

This repository includes a simple Helm chart (in the fibonacci/ directory, for example) that deploys the fibonacci container into Kubernetes. The key files are:

• Chart.yaml – Chart metadata.
• values.yaml – Default values (e.g., image, replicas, etc.).
• templates/ – Contains Kubernetes manifests (Deployment, Service, etc.).

2.2 Creating Secret

Tip

Create a secret to pull the image from Docker Hub:

kubectl create secret docker-registry regcred \
--docker-server=docker.io \
--docker-username=myusername \
--docker-password=MY_PERSONAL_ACCESS_TOKEN \
--docker-email=myemail@example.com

Then reference it in your values.yaml or deployment.yaml:

Tip

Add the following to your deployment.yaml file:

imagePullSecrets:
- name: regcred

2.3 Install Helm Chart

Tip

Navigate to the fibonacci/ directory and install the Helm chart for the first time:

helm install fibonacci . --set image.repository=${DOCKER_USERNAME}/fibonacci_rust --set image.tag=${DOCKER_TAG}

Warning

Do not execute helm install again as it will overwrite the existing deployment.

Tip

If you already have the chart installed and want to upgrade it:

helm upgrade --install fibonacci . --set image.repository=${DOCKER_USERNAME}/fibonacci_rust --set image.tag=${DOCKER_TAG}

Tip

Check the deployment status:

helm status fibonacci
kubectl get pods
kubectl get services
kubectl get deployments

2.4 Launching the Application

Tip

Launch a service to expose the application. Your default web browser will open the application.:

minikube service fibonacci-service

Tip

You can access the logs of the pod in /var/log/fibonacci.log go inside the pod and check the logs

kubectl exec -it <your-pod-name>  -- /bin/sh
cat fibonacci.log

2.5 Monitoring the Application with Prometheus and Grafana

Tip

You can monitor the application using Prometheus and Grafana.

Tip

Access the Prometheus dashboard at http://localhost:9090 and the Grafana dashboard at http://localhost:3000.

Important

You need to port forward the Prometheus and Grafana services to access them locally:

kubectl port-forward svc/prometheus 9090:9090

kubectl port-forward svc/grafana 3000:3000

Tip

Go to http://localhost:9090 to access the Prometheus dashboard. You will see a similar picture as below if you look for the requests_total metric:

Tip

Go to http://localhost:3000 to access the Grafana dashboard. Login with the default username and password (admin/admin). Get your IP with the following command:

kubectl get svc prometheus -n default -o jsonpath='{.spec.clusterIP}'

Tip

Go to the Grafana dashboard and add a new data source with the IP address you just got from the previous command.

http://<your-ip>:9090

Tip

You will see a similar picture as below if you look for the requests_total metric:

3 .Cleaning Up

Warning

This will uninstall helm release.

helm uninstall fibonacci

Caution

This will delete the deployment, secret, service and the minikube cluster.

kubectl delete secret regcred
minkube delete