Dockerize Spring Boot Application

In the fast-evolving landscape of software development, containerization has emerged as a key technology to streamline the deployment and scalability of applications. Docker, a popular containerization platform, allows developers to encapsulate their applications and dependencies into lightweight, portable containers. This article will guide you through the process of Dockerizing a Spring Boot application, enabling you to achieve consistency and ease of deployment across different environments.

Prerequisites:
Before diving into Dockerizing your Spring Boot application, ensure that you have the following prerequisites installed on your machine:
- Docker
- Java Development Kit (JDK)
- Spring Boot application codebase

Create a Dockerfile:
Start by creating a Dockerfile in the root directory of your Spring Boot project. This file will contain instructions for building a Docker image for your application.

# Use an official OpenJDK runtime as a parent image
FROM openjdk:11-jre-slim

# Set the working directory to /app
WORKDIR /app

# Copy the current directory contents into the container at /app
COPY . /app

# Specify the command to run on container start
CMD ["java", "-jar", "your-application.jar"]

Build the Docker Image:
Open a terminal, navigate to the project's root directory, and execute the following command to build the Docker image.
```
docker build -t your-image-name .
```
Run the Docker Container:
Once the image is built successfully, you can run a Docker container using the following command:
```
docker run -p 8080:8080 your-image-name
```
Replace your-image-name with the name you provided during the image build.
Access Your Spring Boot Application:
Open a web browser and navigate to http://localhost:8080 to access your Spring Boot application running inside the Docker container.
Congratulations! You've successfully Dockerized your Spring Boot application.
Additional Docker Commands:
- To list running containers: docker ps
- To stop a running container: docker stop container-id
- To remove a container: docker rm container-id
- To remove an image: docker rmi image-id
Docker Compose for Multi-Container Applications:
For more complex applications with multiple services, consider using Docker Compose. Create a docker-compose.yml file to define and run multi-container Docker applications.
```
version: '3'
services:
  app:
    image: your-image-name
    ports:
      - "8080:8080"
```
Run the application using:
```
docker-compose up
```
Access your application as usual.