Project Overview

This project demonstrates the basic workings of Docker and Kubernetes, focusing on:

1. A simple Hello-world Docker container.
2. A Python Flask ping-pong service that responds to "ping".
3. A Go program for pattern detection in string.

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Setting Up Docker and Kubernetes

Docker was pre-installed on my machine. I enabled Kubernetes in Docker to deploy and manage containerized applications.

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Hello World

Running Locally with Docker

I pulled the hello-world Docker image from Docker Hub and ran it in a Docker container on my local machine. This service prints "Hello, Docker!" to the Terminal.

Deploying with Kubernetes

I deployed the hello-world Docker container using Kubernetes. The hello-world-docker folder contains a hello-world.yaml file, which defines the application and its deployment to a Kubernetes cluster.

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Breakdown of hello-world.yaml

• API Version:
  The apiVersion is v1, which indicates the use of a stable Kubernetes API.

• Kind:
  The kind is Pod, which specifies that the deployment will run the hello-world container inside a Kubernetes Pod.

• Metadata:

  • name: The name of the Pod, which is set to hello-world.

• Spec:

  • containers: Contains the configuration for the container:
    • name: The name of the container, which is hello-world.
    • image: Specifies the Docker image to use, which is hello-world.

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Steps to Run on Terminal

Running Locally with Docker

1. Pull the Docker Image:
   Downloaded the hello-world image from Docker Hub using the following command:

   docker pull hello-world

2. Run the Docker Container: Started the container locally to see the "Hello from Docker!" message:

docker run hello-world

Deploying with Kubernetes

1. Apply the Kubernetes Configuration: The hello-world.yaml file contains deployment specifications. Used it to deploy the application to a Kubernetes cluster:

kubectl apply -f hello-world-docker/hello-world.yaml

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Ping Pong Service

This service implements a simple Python script that responds to the /ping endpoint with the message "pong". The service listens on port 5000.

Folder Structure

The code for this service is located in the ping-pong-python folder. It contains the following files:

1. ping-pong-python.py

This file contains the Python code to:

• Listen on port 5000.
• Respond to the /ping endpoint with the message "pong".

2. Dockerfile

This file contains the configuration to create a Docker image for the ping-pong-python.py script.

3. ping-pong-deployment.yaml

This file contains the Kubernetes deployment configuration for the Ping Pong service.

Breakdown of ping-pong-deployment.yaml:

• apiVersion: apps/v1 (a stable API version for Kubernetes).
• kind: Deployment (to manage multiple replicas of pods running the Ping Pong service).
• metadata:
  • name: Name of the Deployment (ping-pong-deployment).
• spec:
  • selector:
    • matchLabels: Identifies the pod with the label name: ping-pong-app.
  • template:
    • metadata:
      • labels: Sets the pod label to name: ping-pong-app.
    • spec:
      • containers:
        • image: The container image (ashwin0711/ping-pong-app).
        • name: The container name (ping-pong-app-container).
        • ports:
          • containerPort: Exposes port 5000 from the container.

4. Makefile

This file automates the following tasks:

• Building the Docker image for the Ping Pong service.
• Deploying the containerized application to Kubernetes.

Go Program: Pattern Detection

Overview

This program checks if a string follows a specific pattern:

• Starts with "i" or "I".
• Contains "a" or "A" anywhere in the middle.
• Ends with "n" or "N".

Code Location

The code for this program is located in the main.go file.

How It Works

1. Reads an input string.
2. Evaluates the string against the defined pattern.
3. Returns whether the string matches the pattern.