How Can You Easily Create Your First Docker Image With a Dockerfile for Reliable App Deployment?

What Are the Simple Steps to Build a Successful Docker Image Using a Dockerfile for Your Project?

Making your own Docker image with a Dockerfile is a smart way to run your app anywhere. This process means you don’t have to set up everything again and again. Here’s how you can do it, step by step, using clear language and easy actions.

What Is a Docker Image?

A Docker image is like a small box. Inside, you put everything your app needs—your code, the tools, and the libraries. This box can run on any computer that has Docker installed. It helps your app work the same way, every time, everywhere.

What Is a Dockerfile?

A Dockerfile is a plain text file. It has a list of instructions. These instructions tell Docker how to build your image. Think of it as a recipe. You write what you need, and Docker follows your steps from the top to the bottom.

Steps to Create Your First Docker Image

Step 1: Get Docker Ready

Make sure Docker is installed and running on your computer. If you don’t have it yet, download it from the official Docker website.

Step 2: Make a Project Folder

1. Open your terminal.
2. Make a new folder for your project:

   mkdir my-docker-app
   cd my-docker-app

Step 3: Create a Dockerfile

1. In your project folder, open your text editor.
2. Make a new file called Dockerfile (no file extension).

Step 4: Write the Dockerfile Instructions

Here’s a simple example for a Python app:

FROM ubuntu:latest
WORKDIR /usr/src/app
COPY . .
RUN apt-get update && apt-get install -y \
python3 \
python3-pip
CMD ["python3", "mteScript.py"]

• FROM ubuntu:latest tells Docker to start from the latest Ubuntu image.
• WORKDIR /usr/src/app sets the working folder inside the image.
• COPY . . copies everything from your project folder into the image.
• RUN apt-get update && apt-get install -y python3 python3-pip installs Python and pip.
• CMD ["python3", "mteScript.py"] tells Docker what to run when the container starts.

Step 5: Add Your Python Script

In the same folder, create a file called mteScript.py.

Add this code:

def message():
print("Hi Geeks! Welcome to maketecheasier.com")
if __name__ == "__main__":
message()

Step 6: Build Your Docker Image

In your terminal, run:

docker build -t python-docker-demo .

• -t python-docker-demo names your image.
• The . means Docker should look for the Dockerfile in the current folder.

If you used a different file name for your Dockerfile, use:

docker build -f ExampleDockerfile -t python-docker-demo .

Step 7: Check Your Image

To see your new image, run:

docker images

Your image should be listed as python-docker-demo.

Step 8: Test Your Image

To run your app in a container, use:

docker run python-docker-demo

You should see the message from your Python script appear in the terminal.

Building your first Docker image with a Dockerfile is a great way to make your app easy to run and share. It brings confidence and peace of mind, knowing your app will work the same way, every time, on any machine. You now have a clear, simple path to create and run your own Docker image. This skill will make your app development and deployment much smoother and more reliable.