Task Management Platform

Microservice-based task management platform with task lifecycle, event-driven statistics, notifications, and Keycloak-ready authentication.

Highlights

• Microservice architecture with a single API entry point (api-gateway)
• Authentication is being moved to Keycloak
• Role-based access from Keycloak (ROLE_USER, ROLE_ADMIN)
• Task lifecycle: create, update, start, complete, delete
• Event-driven integration via Kafka
• Aggregated statistics service (global and per-user)
• Notification service with MongoDB log storage
• Observability stack: Prometheus, Grafana, Zipkin, Loki

Architecture

flowchart LR
    GW["API Gateway"]

    GW --> US["user-service"]
    GW --> TS["task-service"]
    GW --> SS["statistics-service"]

    TS -->|"validate user via Feign"| US

    TS -->|"TaskEvent"| K["Kafka"]
    K --> NS["notification-service"]
    K --> SS

    US --> UDB[("PostgreSQL\nuser-db")]
    TS --> TDB[("PostgreSQL\ntask-db")]
    SS --> SDB[("PostgreSQL\nuser-db")]
    NS --> MDB[("MongoDB")]

    TS --> R[("Redis cache")]

    TS --> Z["Zipkin"]
    US --> Z
    SS --> Z
    NS --> Z
    GW --> Z

Loading

Services

Service	Responsibility	Storage / Integration
api-gateway	Single entry point, request routing, CORS	Spring Cloud Gateway
user-service	Profile management, user status, admin operations	PostgreSQL (user-db)
task-service	Task CRUD + lifecycle + business rules	PostgreSQL (task-db), Redis, Kafka
statistics-service	Global and per-user task analytics	PostgreSQL (user-db), Kafka
notification-service	Sends notifications and stores notification logs	Kafka, MongoDB, SMTP
common	Shared DTO/models/events	Maven module

Tech Stack

Backend

• Java 21
• Spring Boot 3
• Spring Cloud Gateway
• Spring Data JPA
• Spring Validation
• Spring Security
• OpenFeign

Data & Messaging

• PostgreSQL 15
• MongoDB
• Redis
• Apache Kafka (KRaft)
• Liquibase

Observability

• Micrometer
• Prometheus
• Grafana
• Zipkin
• Loki

Infra & Dev

• Docker / Docker Compose
• Maven (multi-module)

Project Structure

task-management/
|- api-gateway/
|- common/
|- db-init/
|- k8s/
|- notification-service/
|- statistics-service/
|- task-service/
|- user-service/
|- docker-compose.yaml
|- pom.xml
`- README.md

Prerequisites

• Docker + Docker Compose
• Optional for local run (without Docker): Java 21, Maven

Configuration

Create root .env:

DB_USERNAME=postgres
DB_PASSWORD=postgres
DB_uNAME=user-db
DB_tNAME=task-db
GMAIL_USER=your_email@gmail.com
GMAIL_PASSWORD=your_app_password

Run with Docker Compose

docker compose up --build -d

Check containers:

docker compose ps

Stop:

docker compose down

Main URLs

• Gateway: http://localhost:8080
• Grafana: http://localhost:3000
• Prometheus: http://localhost:9090
• Zipkin: http://localhost:9411
• Mongo Express: http://localhost:8085

API Overview (via Gateway)

Base URL: http://localhost:8080

Users

Keycloak will issue access tokens. The gateway and services should accept Bearer tokens from Keycloak.

• GET /users/{id}
• PUT /users/{id}

Admin routes:

• GET /users
• POST /users
• POST /users/{id}/banUser
• DELETE /users/{id}/delete

Tasks

• GET /tasks
• GET /tasks/{id}
• POST /tasks
• PUT /tasks/{id}
• DELETE /tasks/{id}
• POST /tasks/{id}/start
• POST /tasks/{id}/complete

Statistics

• GET /stats/task
• GET /stats/user/{userId}

Event Flow

task-service publishes TaskEvent to Kafka topic task-events.

Consumers:

• statistics-service updates global and per-user counters
• notification-service sends notifications and stores event logs in MongoDB