https://github.com/buzzcosm/hello-docker
A simple Spring Boot application demonstrating various Docker containerization approaches for Java applications.
https://github.com/buzzcosm/hello-docker
docker docker-compose docker-image graalvm-native-image java-21-lts maven spring-boot
Last synced: about 2 months ago
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A simple Spring Boot application demonstrating various Docker containerization approaches for Java applications.
- Host: GitHub
- URL: https://github.com/buzzcosm/hello-docker
- Owner: buzzcosm
- License: mit
- Created: 2025-05-30T21:26:36.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2025-06-04T07:48:44.000Z (about 1 year ago)
- Last Synced: 2025-09-01T12:47:35.985Z (10 months ago)
- Topics: docker, docker-compose, docker-image, graalvm-native-image, java-21-lts, maven, spring-boot
- Language: Dockerfile
- Homepage:
- Size: 228 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Hello Docker
A simple Spring Boot application demonstrating various Docker containerization approaches for Java applications.
## Description
This project showcases how to containerize a Spring Boot application using different Docker strategies:
- Standard JAR-based containerization
- Multi-stage builds for optimized images
- GraalVM native image compilation for smaller footprint and faster startup
The application itself is a minimal REST API with a single endpoint:
- `GET /` - Returns the greeting message "Hello Docker 👋"
## Prerequisites
- Java 21
- Docker
- Docker Compose
- Maven 3.9+ (or use the included Maven wrapper)
## Getting Started
### Clone the Repository
```bash
git clone https://github.com/buzzcosm/hello-docker.git
cd hello-docker
```
### Build and Run Locally
```bash
./mvnw clean package
java -jar target/hello-docker.jar
```
The application will be available at http://localhost:8080
## 🐳 Docker Containerization Benchmark
## 🐳🔧 Dockerfile commands
* FROM initializes the build stage and defines the base image to build on.
* WORKDIR sets the working directory for any RUN, CMD, ENTRYPOINT, COPY, and ADD directives that follow in the Dockerfile.
* COPY copies new files or directories into the Docker image.
* RUN executes commands on top of the current image as a new layer and commits the results.
* EXPOSE configures Docker to open a specific network port for listening on the container, in this case port 8080.
* ENV sets environment variables.
* CMD provides the default execution command when the container is run.
## 🧪 Automated Build & Test Scripts
**s.** *directory*: `scripts/build_and_test_image_v*.sh`
This script will:
- Check if Docker is running
- Automatically build the image
- Start the container using docker-compose.yml
- Test the HTTP response for the string Hello Docker
- Print the result
- Stop and remove the container afterward
## 🧩(optional) Java containers with Jib
- [Building Java containers with Jib](https://cloud.google.com/java/getting-started/jib)
Helper - Get Digest if image:
> `docker inspect : --format='{{index .RepoDigests 0}}'`
### Build Docker Image
```shell
./mvnw clean compile jib:dockerBuild
```
### Test
```shell
docker run --platform linux/amd64 -it --rm -p 8080:8080 --name hello-docker-jib hello-docker:jib
```
## 🧩(optional) Spring-Boot Container
- [Packaging OCI Images](https://docs.spring.io/spring-boot/maven-plugin/build-image.html)
```shell
./mvnw spring-boot:build-image -Dspring-boot.build-image.imageName=hello-docker:spring-boot-build
```