Day 2/40 Days of K8s: Dockerize a Project 🐳

Prerequisites:

1. Docker Installation:

   • Use Play with Docker (dockerhub credentials required)

   • (Or) Install Docker Desktop locally (recommended for future use) https://www.docker.com/products/docker-desktop/

Steps:

1. Clone the repo:

    git clone https://github.com/docker/getting-started-app.git
   

2. Navigate to the project directory:

    cd getting-started-app/
   

3. Create a Dockerfile:

    vi Dockerfile
   

4. Add the following content to the Dockerfile:

# Use an official base image of Linux OS where our app will run
FROM node:18-alpine

# Set the working directory inside the container
WORKDIR /app

# Copy all files from the current directory to /app in the container
COPY . .

# Install dependencies and build your application
RUN yarn install --production

# Command to run on container startup
CMD ["node", "src/index.js"]

# Expose the port your app listens on
EXPOSE 3000

5. Build Docker Image:

    docker build -t vivekmanne/todo-app:v1 .
   

6. List Docker Images:

    docker images
   

7. Run Docker Container:

    docker run -dp 3000:3000 vivekmanne/todo-app:v1
   

8. View Running Containers:

    docker ps
   

9. Exec into Container Shell:

    docker exec -it d437e2fbaec1 /bin/sh
   

10. View Container Logs:

    docker logs -f d437e2fbaec1
    

11. Push Docker Image to Docker Hub:

    docker login
    docker push vivekmanne/todo-app:v1
    

Challenge:

For this simple application, the image is over 200MB:

REPOSITORY                TAG       IMAGE ID       CREATED             SIZE
vivekmanne/todo-app       v1        3dbe0cf498bb   About an hour ago   217MB

Optimization:

We'll optimize this to create a leaner image for:

1. Fast processing / performance

2. Less disk space consumption

3. Reduced attack surface area

Our hero: "Multi-stage-Dockerfile" - Coming up in Day 3 of the CKA series!

Stay tuned for more Docker and Kubernetes insights! 🚀 #40DaysOfKubernetes #Docker #Containerization #DevOps