docker-kubernetes-python-app

This project is a Python flask application, that is containerized by docker and deployed using Kubernetes.

The Architecture of the project will flow like this:

Prerequisites

To successfully build, package and deploy the application, the following needs to be installed on your machine - either local machine or virtual machine:

• Docker: the containerization engine. Click HERE to install docker.
• Minikube: a local kubernetes installation which makes it easy to learn and develop applications on kubernetes easily. Click HERE to install minikube.
• Kubectl: a command line utility to interact with kubernetes clusters. Install kubectl from HERE
• VS code: code editor to build your code and configuration files. Install VS Code from HERE

Write your python code

Create an app.py file on your vscode and write a simple python code using flask framework to return Hello JT...Welcome to Kodecamp to the screen

Then create another file called reuirements.txt to store your major application requirement. Here, we have just one requirement which is flask:

Dockerize the application

After creating the application source code, and the requirements file, we will write a Dockerfile to containerize the application using a python slim image

To build the docker image, run this simple command

docker build -t johntoby/python-app .

This will build the application image named johntoby/python-app

To run the application locally using docker and expose it on port 5000, we will run the following command:

docker run -it -p 5000:5000 johntoby/python-app

Since the application is running on an ec2 instance, I will browse the public ip of my ec2 instance on port 5000 i.e. 54.89.171.65:5000

This confirms the application is successfully dockerized and running on port 5000.

Push the image to dockerhub

Login to dockerhub and authenticate to your CLI. Then run this command to push the local image to dockerhub

docker push johntoby/python-app

Deply the application to kubernetes

We will use minikube to deploy the application on kubernetes.

Run this command to start minikube

minikube start

Create deployment.yaml file to deploy the image

run this command to check if your deployment is created successfully

kubectl get deployment

Create your service.yaml file to expose the application on port 5000

Run this command to check if your service is successfully created

kubectl get service

To check the service, run this command

minikube service

Finally, to port-forward the service to be able to view it on the browser, run this command:

kubectl port-forward service/kodecamp-service 5000:5000

The application should be available on the browser at localhost:5000

Thanks.