Step-by-Step Guide: Implementing & Testing the Logistics Service

This guide provides a detailed, step-by-step walkthrough for setting up, running, and testing the Logistics Service Module.

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🔧 Step 1: Environment Setup

1.1 Install Prerequisites

✅ Required Software:

• Java 17+ (or Node.js 16+)
• Docker (for databases & messaging)
• PostgreSQL (or MongoDB)
• Kafka (or RabbitMQ)
• Redis (caching)

📌 Install Docker (if missing):

# Linux (Debian/Ubuntu)
sudo apt update && sudo apt install docker.io docker-compose

# Mac (Homebrew)
brew install docker docker-compose

1.2 Clone the Repository

git clone https://github.com/your-repo/logistics-service.git
cd logistics-service

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⚙️ Step 2: Configure the Service

2.1 Set Up Environment Variables

Create a .env file in the root directory:

# Database
DB_URL=jdbc:postgresql://localhost:5432/logistics
DB_USER=admin
DB_PASSWORD=admin123

# Messaging
KAFKA_BROKERS=localhost:9092

# Caching
REDIS_HOST=localhost
REDIS_PORT=6379

# Fraud Detection
FRAUD_DETECTION_ENABLED=true
MAX_RETRIES=3

2.2 Start Dependencies with Docker

docker-compose up -d postgres kafka redis

✅ Verify running containers:

docker ps

(Should show postgres, kafka, and redis containers.)

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🚀 Step 3: Run the Logistics Service

3.1 Build & Run (Java/Spring Boot)

./mvnw clean install
./mvnw spring-boot:run

(Server starts at http://localhost:8080)

3.2 Build & Run (Node.js)

npm install
npm start

(Server starts at http://localhost:3000)

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🧪 Step 4: Testing the Service

4.1 Unit Tests

# Java
./mvnw test

# Node.js
npm test

✅ Expected: All tests pass (✔️ 15/15 tests OK).

4.2 Integration Tests

# Java
./mvnw verify -Pintegration-test

# Node.js
npm run test:integration

✅ Checks:

• Database connectivity ✅
• Kafka message publishing ✅
• Redis caching ✅

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📡 Step 5: API Testing (Manual Verification)

5.1 Test Delivery Routing

Request:

curl -X POST http://localhost:8080/api/deliveries \
  -H "Content-Type: application/json" \
  -d '{
    "orderId": "test123",
    "destination": "home",
    "address": "123 Main St"
  }'

✅ Expected Response:

{
  "status": "ROUTED",
  "deliveryMethod": "HOME_DELIVERY"
}

5.2 Test Fraud Detection

Trigger a suspicious delivery:

curl -X POST http://localhost:8080/api/fraud/check \
  -H "Content-Type: application/json" \
  -d '{
    "orderId": "fraud-test",
    "userId": "user-789",
    "location": "unexpected_country"
  }'

✅ Expected Response (Blocked):

{
  "status": "BLOCKED",
  "reason": "Suspicious location"
}

5.3 Test Error Handling

Simulate a failing delivery:

curl -X POST http://localhost:8080/api/deliveries \
  -H "Content-Type: application/json" \
  -d '{
    "orderId": "fail-test",
    "destination": "home",
    "simulateFailure": true
  }'

✅ Expected Behavior:

• Retries 3 times (check logs)
• Falls back to Drop Zone Network
• Logs error in Redis/ELK

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📊 Step 6: Monitoring & Logs

6.1 Check Application Logs

# Java (Spring Boot)
tail -f logs/application.log

# Node.js
npm run logs

6.2 Verify Kafka Messages

docker exec -it kafka /bin/kafka-console-consumer \
  --bootstrap-server localhost:9092 \
  --topic delivery-events

(Should show delivery routing events.)

6.3 Check Redis Cache

docker exec -it redis redis-cli KEYS "*"

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🚨 Troubleshooting

Issue	Solution
DB Connection Failed	Check .env DB credentials
Kafka Not Responding	Restart Kafka: docker restart kafka
Fraud Detection False Positives	Adjust thresholds in FraudConfig
High Retry Failures	Check network connectivity to HDS/DZN

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🎉 Next Steps

• Deploy to Kubernetes/AWS
• Set up Prometheus/Grafana for metrics
• Add CI/CD (GitHub Actions)

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✅ Success! Your Logistics Service is now running and testable. 🚀
For issues, refer to the GitHub repo.