pastebin-app

Full-stack pastebin demo with a Spring Boot API, React UI, Keycloak login, PostgreSQL metadata storage, MinIO paste-content storage, and Hazelcast-backed caching.

Русская версия

Field	Value
Status	Finished sandbox demo
Type	Full-stack demo / integration playground
Primary stack	Java 17, Spring Boot 3.0.10, React 18, CRA 5, Keycloak 20, PostgreSQL 14, MinIO, Hazelcast
Main flow	Authenticated user creates a paste, backend stores metadata in PostgreSQL and content in MinIO, then retrieves by hash

Project scope

• Demo / sandbox project, not a production deployment.
• Useful for local experiments with JWT/OIDC authentication, object storage, API documentation, caching, and containerized dependencies.
• Intended to show architecture and integration points rather than a hardened deployment model.

Quick start

cp .env.example .env
# Fill placeholder values before first run.
docker compose up -d

Run the backend and frontend in separate terminals:

cd pastebin-backend
./gradlew bootRun --args='--spring.profiles.active=dev'

cd pastebin-frontend
npm install
npm start

Service matrix

Service	Path / image	Runtime/framework	Port	Responsibility	Verify command
Frontend	pastebin-frontend/	React 18.2.0, CRA 5.0.1, Keycloak JS 20.0.3, PrimeReact 9.3.0	3000	Browser UI, Keycloak login, paste create/find forms	npm test, npm run build
Backend	pastebin-backend/	Java 17, Spring Boot 3.0.10, Gradle 8.2.1	8081	REST API, JWT validation, persistence orchestration	./gradlew test, ./gradlew build
PostgreSQL	postgres:14.8-alpine3.18	Docker Compose	54322 -> 5432	Paste metadata and tags	docker compose ps postgres
Keycloak DB	postgres:14.8-alpine3.18	Docker Compose	5434 -> 5432	Keycloak persistence	docker compose ps keycloak-postgres
Keycloak	quay.io/keycloak/keycloak:20.0.2	Docker Compose	8282 -> 8080	Local OIDC provider, realm pastebin	docker compose ps keycloak
MinIO	minio/minio	Docker Compose	9000, 9001	Paste content object storage	docker compose ps minio
Hazelcast Management Center	hazelcast/management-center:5.2.0	Docker Compose	8080	Local cache observability UI	docker compose ps hazelcast-management-center

Architecture

React UI (localhost:3000)
  -> Keycloak (localhost:8282, realm pastebin, frontend-client)
  -> Spring Boot API (localhost:8081, Bearer JWT)
       -> PostgreSQL: paste metadata, tags, expiration
       -> MinIO: paste text content under bin/<hash>
       -> Hazelcast: pasteByHash cache and hashQueue

Important boundaries:

• Directional UI/API calls are hardcoded for local development: frontend calls http://localhost:8081, Keycloak runs at http://localhost:8282.
• Backend allows unauthenticated access only to /api/v1/docs/**; all other requests require a Bearer JWT.
• Paste text is stored in MinIO. PostgreSQL stores metadata and content_path.
• realm-export.json is present for Keycloak realm bootstrap. docker-compose.yml starts Keycloak with --import-realm; if the realm is not imported automatically in a local setup, import that file manually in Keycloak.

API overview

Method	Path	Auth	Description
POST	/api/v1/paste	Bearer JWT	Create a paste and return its hash
GET	/api/v1/paste/{hash}	Bearer JWT	Load paste metadata and content by hash
GET	/api/v1/docs/swagger-ui.html	Public	Swagger UI
GET	/api/v1/docs/api-docs	Public	OpenAPI JSON

Create payload shape:

{
  "title": "Example",
  "author": "Mark",
  "tags": ["demo", "pastebin"],
  "text": "Paste content",
  "expiration": "N"
}

The UI exposes N, 10m, and 1M. The backend also accepts 1Y, 1H, 1D, 1W, 2W, 6M, or a yyyy-MM-dd date.

Local development

Backend

cd pastebin-backend
./gradlew test
./gradlew spotlessCheck
./gradlew spotbugsMain
./gradlew bootRun --args='--spring.profiles.active=dev'

Frontend

cd pastebin-frontend
npm install
npm test
npm run build
npm start

Useful URLs

Component	URL	Notes
Frontend	http://localhost:3000	React development server
Backend API	http://localhost:8081/api/v1/paste	Requires Bearer JWT
Swagger UI	http://localhost:8081/api/v1/docs/swagger-ui.html	Public docs path from application-dev.yml
OpenAPI JSON	http://localhost:8081/api/v1/docs/api-docs	Public docs path from application-dev.yml
Keycloak	http://localhost:8282	Local admin/realm UI
Hazelcast Management Center	http://localhost:8080	Local observability UI
MinIO Console	http://localhost:9001	Local object storage console

Limitations / security

• Do not use placeholder credentials outside local development.
• Keep .env local and replace every placeholder before the first run.
• Local frontend config hardcodes Keycloak and backend URLs; external deployments need configuration work.
• Backend disables CSRF and uses stateless JWT validation for the demo API.
• This repo is intentionally a demo and should not be treated as a secure production deployment.
• No CI is currently configured.

Status

Portfolio/demo project. The code is public as an architecture and implementation reference, not as a production-ready service.

License

MIT