Purchase-Sale Service Configuration - SGIVU Config Repository

The Purchase-Sale Service (sgivu-purchase-sale) orchestrates vehicle purchase and sale transactions by coordinating data from User, Client, and Vehicle services.

Service Overview

Port

8084

Database

PostgreSQL

Type

Orchestration

Role

Transaction Management

Key Features

Transaction orchestration across multiple services
Purchase and sale record management
Integration with User, Client, and Vehicle services
Database migration with Flyway
RESTful API with OpenAPI documentation
Internal service authentication

Base Configuration

Server Settings

server:
  port: ${PORT:8084}

JPA Configuration

spring:
  jpa:
    open-in-view: false

Disabling open-in-view enforces proper transaction boundaries in this orchestration service.

Flyway Migration

spring:
  flyway:
    enabled: true
    locations: classpath:db/migration
    baseline-on-migrate: ${FLYWAY_BASELINE_ON_MIGRATE:false}
    baseline-version: 0
    validate-on-migrate: true

Database Configuration

Development
Production

spring:
  datasource:
    url: jdbc:postgresql://${DEV_PURCHASE_SALE_DB_HOST:host.docker.internal}:${DEV_PURCHASE_SALE_DB_PORT:5432}/${DEV_PURCHASE_SALE_DB_NAME}
    username: ${DEV_PURCHASE_SALE_DB_USERNAME}
    password: ${DEV_PURCHASE_SALE_DB_PASSWORD}
    driver-class-name: org.postgresql.Driver
  jpa:
    hibernate:
      ddl-auto: validate
    show-sql: true
    properties:
      hibernate:
        format_sql: true
  flyway:
    baseline-on-migrate: true
    clean-disabled: true

Development enables SQL logging with formatting for debugging transactions.

spring:
  datasource:
    url: jdbc:postgresql://${PROD_PURCHASE_SALE_DB_HOST}:${PROD_PURCHASE_SALE_DB_PORT}/${PROD_PURCHASE_SALE_DB_NAME}
    username: ${PROD_PURCHASE_SALE_DB_USERNAME}
    password: ${PROD_PURCHASE_SALE_DB_PASSWORD}
    driver-class-name: org.postgresql.Driver
  jpa:
    hibernate:
      ddl-auto: validate
  flyway:
    clean-disabled: true
    baseline-on-migrate: ${FLYWAY_BASELINE_ON_MIGRATE:false}

Production disables SQL logging for performance.

This service maintains its own database for transaction records while querying other services for related data.

Service Integration

Eureka Registration

eureka:
  instance:
    instance-id: ${spring.cloud.client.hostname}:${spring.application.name}:${random.value}
  client:
    service-url:
      defaultZone: ${EUREKA_URL:http://sgivu-discovery:8761/eureka}

Service Discovery Map

This service integrates with all business services:

services:
  map:
    sgivu-auth:
      name: sgivu-auth
      url: ${SGIVU_AUTH_URL:http://sgivu-auth:9000}
    sgivu-client:
      name: sgivu-client
      url: ${SGIVU_CLIENT_URL:http://sgivu-client:8082}
    sgivu-user:
      name: sgivu-user
      url: ${SGIVU_USER_URL:http://sgivu-user:8081}
    sgivu-vehicle:
      name: sgivu-vehicle
      url: ${SGIVU_VEHICLE_URL:http://sgivu-vehicle:8083}

Service Dependencies

sgivu-auth: Token validation and authorization
sgivu-client: Client (customer) information for transactions
sgivu-user: User information for transaction recording
sgivu-vehicle: Vehicle details for purchase/sale records

This is the only service that communicates with all other business services, making it a true orchestration layer.

Internal Service Authentication

service:
  internal:
    secret-key: "${SERVICE_INTERNAL_SECRET_KEY}"

The service uses this secret to authenticate API calls to User, Client, and Vehicle services.

Transaction Orchestration

The Purchase-Sale Service coordinates complex transactions:

Purchase Flow Example

Receive purchase request via API
Validate user (call User Service)
Validate client (call Client Service)
Validate vehicle availability (call Vehicle Service)
Create transaction record in local database
Update vehicle status (call Vehicle Service)
Return transaction confirmation

Sale Flow Example

Receive sale request via API
Validate seller (call User Service)
Validate buyer client (call Client Service)
Validate vehicle ownership (call Vehicle Service)
Create sale record in local database
Transfer vehicle ownership (call Vehicle Service)
Generate sale documentation

Consider implementing the Saga pattern for distributed transaction management with compensating actions.

Observability

Actuator Endpoints

Development
Production

management:
  endpoints:
    web:
      exposure:
        include: "*"
  endpoint:
    health:
      show-details: always

management:
  endpoints:
    web:
      exposure:
        include: health, info, prometheus
  endpoint:
    health:
      show-details: never

Distributed Tracing

management:
  tracing:
    sampling:
      probability: 0.1
  zipkin:
    tracing:
      endpoint: http://sgivu-zipkin:9411/api/v2/spans

Distributed tracing is especially valuable here to trace requests across User, Client, and Vehicle services.

Logging

logging:
  level:
    root: INFO

API Documentation

springdoc:
  swagger-ui:
    url: /docs/purchase-sale/v3/api-docs
    configUrl: /docs/purchase-sale/v3/api-docs/swagger-config

Production

openapi:
  server:
    url: ${OPENAPI_SERVER_URL}

Required Environment Variables

All Environments

Variable	Description	Example
`SERVICE_INTERNAL_SECRET_KEY`	Shared secret for internal APIs	`your-secret-key`

Development

Variable	Description	Default
`DEV_PURCHASE_SALE_DB_HOST`	Database host	`host.docker.internal`
`DEV_PURCHASE_SALE_DB_PORT`	Database port	`5432`
`DEV_PURCHASE_SALE_DB_NAME`	Database name	Required
`DEV_PURCHASE_SALE_DB_USERNAME`	Database username	Required
`DEV_PURCHASE_SALE_DB_PASSWORD`	Database password	Required

Production

Variable	Description
`PROD_PURCHASE_SALE_DB_HOST`	Database host
`PROD_PURCHASE_SALE_DB_PORT`	Database port
`PROD_PURCHASE_SALE_DB_NAME`	Database name
`PROD_PURCHASE_SALE_DB_USERNAME`	Database username
`PROD_PURCHASE_SALE_DB_PASSWORD`	Database password
`OPENAPI_SERVER_URL`	Public API docs URL

Optional

Variable	Description	Default
`PORT`	Service port	`8084`
`EUREKA_URL`	Eureka server URL	`http://sgivu-discovery:8761/eureka`
`SGIVU_AUTH_URL`	Auth service URL	`http://sgivu-auth:9000`
`SGIVU_CLIENT_URL`	Client service URL	`http://sgivu-client:8082`
`SGIVU_USER_URL`	User service URL	`http://sgivu-user:8081`
`SGIVU_VEHICLE_URL`	Vehicle service URL	`http://sgivu-vehicle:8083`

API Endpoints

Typical Purchase-Sale Service endpoints:

GET    /api/purchase-sales              - List transactions
GET    /api/purchase-sales/{id}         - Get transaction by ID
POST   /api/purchase-sales/purchase     - Create purchase
POST   /api/purchase-sales/sale         - Create sale
PUT    /api/purchase-sales/{id}         - Update transaction
DELETE /api/purchase-sales/{id}         - Cancel transaction
GET    /api/purchase-sales/client/{id}  - Get client transactions
GET    /api/purchase-sales/vehicle/{id} - Get vehicle history

All endpoints require authentication through the gateway.

Transaction Data Model

Typical transaction entity includes:

Transaction ID and type (purchase/sale)
User ID (who processed the transaction)
Client ID (customer)
Vehicle ID
Transaction amount and currency
Transaction date and status
Payment details
Notes and metadata

Error Handling

The orchestration service must handle failures gracefully:

Circuit Breaker Pattern

Consider implementing circuit breakers for service calls:

resilience4j:
  circuitbreaker:
    instances:
      userService:
        failure-rate-threshold: 50
        wait-duration-in-open-state: 10000
      clientService:
        failure-rate-threshold: 50
        wait-duration-in-open-state: 10000
      vehicleService:
        failure-rate-threshold: 50
        wait-duration-in-open-state: 10000

Retry Strategy

resilience4j:
  retry:
    instances:
      userService:
        max-attempts: 3
        wait-duration: 1000

Always implement timeout and retry logic when calling downstream services to prevent cascade failures.

Service Communication

RestTemplate / WebClient

The service uses Spring’s HTTP clients to call other services:

// Example: Calling Client Service
ResponseEntity<ClientDto> response = restTemplate.exchange(
    clientServiceUrl + "/api/clients/" + clientId,
    HttpMethod.GET,
    httpEntity,
    ClientDto.class
);

Authentication Headers

Include the internal secret in requests:

HttpHeaders headers = new HttpHeaders();
headers.set("X-Internal-Secret", serviceInternalSecretKey);

Performance Considerations

Caching

Cache frequently accessed data from other services:

spring:
  cache:
    type: caffeine
    caffeine:
      spec: maximumSize=500,expireAfterWrite=10m

Parallel Service Calls

When data from multiple services is needed, call them in parallel:

CompletableFuture<User> userFuture = userService.getUserAsync(userId);
CompletableFuture<Client> clientFuture = clientService.getClientAsync(clientId);
CompletableFuture<Vehicle> vehicleFuture = vehicleService.getVehicleAsync(vehicleId);

CompletableFuture.allOf(userFuture, clientFuture, vehicleFuture).join();

Security

Service-to-Service Authentication

All internal API calls must include the shared secret.

Transaction Authorization

Verify user permissions before allowing transaction creation:

Check user role (admin, sales, etc.)
Validate transaction limits
Audit all operations

Monitoring

Key Metrics

Monitor these metrics for the orchestration service:

Transaction success/failure rates
Service call latencies (User, Client, Vehicle)
Database query performance
Error rates by service
Circuit breaker states

Alerts

Set up alerts for:

High failure rates
Service unavailability
Slow transaction processing
Circuit breaker opens

Configuration Files

sgivu-purchase-sale.yml - Base configuration
sgivu-purchase-sale-dev.yml - Development overrides
sgivu-purchase-sale-prod.yml - Production overrides

User Service

User data provider

Client Service

Client data provider

Vehicle Service

Vehicle data provider

Auth Service

Token validation

Overview

Getting Started

Service Configuration

Environment Management

Operations

​Service Overview

Port

Database

Type

Role

​Key Features

​Base Configuration

​Server Settings

​JPA Configuration

​Flyway Migration

​Database Configuration

​Service Integration

​Eureka Registration

​Service Discovery Map

​Internal Service Authentication

​Transaction Orchestration

​Purchase Flow Example

​Sale Flow Example

​Observability

​Actuator Endpoints

​Distributed Tracing

​Logging

​API Documentation

​Required Environment Variables

​All Environments

​Development

​Production

​Optional

​API Endpoints

​Transaction Data Model

​Error Handling

​Circuit Breaker Pattern

​Retry Strategy

​Service Communication

​RestTemplate / WebClient

​Authentication Headers

​Performance Considerations

​Caching

​Parallel Service Calls

​Security

​Service-to-Service Authentication

​Transaction Authorization

​Monitoring

​Key Metrics

​Alerts

​Configuration Files

​Related Services

User Service

Client Service

Vehicle Service

Auth Service

Build docs developers (and LLMs) love

Service Overview

Key Features

Base Configuration

Server Settings

JPA Configuration

Flyway Migration

Database Configuration

Service Integration

Eureka Registration

Service Discovery Map

Internal Service Authentication

Transaction Orchestration

Purchase Flow Example

Sale Flow Example

Observability

Actuator Endpoints

Distributed Tracing

Logging

API Documentation

Required Environment Variables

All Environments

Development

Production

Optional

API Endpoints

Transaction Data Model

Error Handling

Circuit Breaker Pattern

Retry Strategy

Service Communication

RestTemplate / WebClient

Authentication Headers

Performance Considerations

Caching

Parallel Service Calls

Security

Service-to-Service Authentication

Transaction Authorization

Monitoring

Key Metrics

Alerts

Configuration Files

Related Services