12-Factor Spring Boot Notepad Application

This is a Spring Boot application demonstrating the Twelve-Factor App methodology.

To view the presentation click here.

If you downlaod the repo open presentation.html.

In either case you can also review slide notes for more information.

Prerequisites

• Git
• Heroku CLI
• OpenJDK (Version specified in system.properties, typically 17 or higher)

Building the Deck

To rebuild presentation.html after changing presentation.md, first install marp then run it.

marp presentation.md

Local Development

1. Clone the repository:

   git clone <repository-url>
   cd <repository-directory>

2. Run the application locally using Maven:

   ./mvnw spring-boot:run

   The application will be accessible at http://localhost:8080.

Deployment to Heroku

This application is configured for Heroku deployment using a Procfile and system.properties.

1. Log in to Heroku:

   heroku login

2. Create a Heroku Application You can create a new app directly or specify a name.

   heroku create

   If you omit <your-app-name>, Heroku will generate one for you. This command also sets up a heroku git remote.

3. Provision a External Services

   heroku addons:create heroku-postgresql:essential-0 --wait
   heroku addons:create heroku-redis:mini --wait

4. Deploy the Application: Push your code to the heroku remote (ensure your main branch is up-to-date, e.g., main or master depending on your setup).

   git push heroku main 

   (If your main branch is named differently, like master, use git push heroku master:main or git push heroku master if your Heroku app's default branch is master).

5. Check Build Logs & Status: You can view the build process and logs:

   heroku logs --tail

6. Open the Application: Once deployed, open your application in the browser:

   heroku open

Configuration

• Java Version: Specified in system.properties.
• Process Types: Defined in the Procfile (e.g., web: java -jar target/twelvefactor-notepad-0.0.1-SNAPSHOT.jar).
• Application Properties: Spring Boot configuration is managed in src/main/resources/application.properties and profile-specific properties (e.g., application-dev.properties, application-prod.properties). Heroku Config Vars can be used to override these properties for different environments.

Further Resources & Links

Explore these resources to learn more about the Twelve-Factor App methodology, Spring Boot, and Heroku:

• The Twelve-Factor App: 12factor.net
• Spring Boot Guides: spring.io/guides
• Spring Cloud Documentation: spring.io/projects/spring-cloud
• Twelve-Factor Repository: github.com/heroku/12factor
• Simplifying JVM App Development with Heroku’s Buildpack Magic
• Heroku Platform: heroku.com (for deploying applications)

If you have questions or suggestions regarding this sample application, please open an issue or pull request!