How to Create Docker Image With Dockerfile: A Step-By-Step Guide

How to Create A Base Image Using Scratch? A Step-By-Step Guide

Step 1: Creating A Dockerfile

Firstly we have to create a file with name Dockerfile in your directory.

vim Dockerfile

The following illustrates about creating a Dockerfile:

Step 2: Write Dockerfile Instructions

Inside the Dockerfile write the instructions that needed for defining environment and setup needed for an application that typically includes for specifying image, copying file, installing dependencies and configuring the runtime environment.

# Use an existing base image
FROM ubuntu:latest

# Set the working directory in the container
WORKDIR /app

# Copy application files from host to container
COPY . .

# Install dependencies
RUN apt-get update && apt-get install -y \
    python3 \
    python3-pip

# Set the default command to execute when the container starts
CMD ["python3", "app.py"]

The following screenshot specifies about defining the docker instructions:

Here also ensure to have app.py sample python application as shown in the following:

# app.py

def main():
    print("Hello, Docker!")

if __name__ == "__main__":
    main()

The following screenshot specifies about providing a python application:

Step 3: Build Your Docker Image

Here, in the step build the docker image from the Dockerfile using the following command:

docker build -t myimg .

The following screenshot specifies about building a docker image:

Step 4: Verify The Image

After once buildig the docker image verify it whether it is created successful or not with running following command:

docker images

The following command specifies the successful creation of docker image:

Step 5: Test the Docker Image ( Optional )

For the testing the docker image locally try on creating a container with that image with the following command:

docker run -d -p 8080:80 myimg

The following screenshot specifies about the creating a container to the new build docker image:

How to Create Docker Image?

Docker is a powerful containerization tool that enables developers to package their applications and their dependencies into a single unit called Docker image. The Docker image offers seamless deployment, scalability, and portability. In this article, I will make sure that you understand what is docker and guide you through the steps to create a Docker image.

Table of Content

What is Docker?
What is Docker Image?
Why Create Docker Images?
How to Create Docker Image With Dockerfile: A Step-By-Step Guide
How to Create A Base Image Using Scratch? A Step-By-Step Guide
How to Create a Full Image Using tar?
How to Optimize Your Docker Image Size?
How to Host Your Docker Image?
Examples of Docker Commands for Creating a Dockerfile
Dockerfile vs Docker Image Vs Container
Docker Image Commands
Key Commands of Docker Image And Docker Container
Examples of Docker Image UseCases
How To Create A Docker Image On Docker Desktop: A Step-By-Step Guide
How to Create a Docker Image from Docker Container? A Step-By-Step Guide
Conclusion
Create Docker Image – FAQs