The API Gateway Entry Point

What Was Built

ApiGatewayApplication.java — the single @SpringBootApplication that wires all 8 modules together.

@SpringBootApplication(scanBasePackages = "com.iam")
@EntityScan(basePackages = "com.iam.authcore.entity")
@EnableJpaRepositories(basePackages = "com.iam.authcore.repository")
public class ApiGatewayApplication {
    public static void main(String[] args) {
        SpringApplication.run(ApiGatewayApplication.class, args);
    }
}

Component Scanning

All modules live under com.iam.*:

com.iam.authcore
com.iam.oauth-oidc
com.iam.saml-federation
com.iam.scim
com.iam.mfa
com.iam.device-flow
com.iam.demo-resource

scanBasePackages = "com.iam" picks up all @Component, @Service, @Controller beans across all modules without listing each package explicitly.

Entities and repositories are only in auth-core. The @EntityScan and @EnableJpaRepositories annotations are scoped to com.iam.authcore.entity and com.iam.authcore.repository respectively — they don't need to scan broadly.

Configuration

# backend/api-gateway/src/main/resources/application.yml
spring:
  datasource:
    url: jdbc:postgresql://localhost:5432/iam_engine
    username: iam_user
    password: ${POSTGRES_PASSWORD}  # resolved from infra/.env
  data:
    redis:
      host: localhost
      port: 6379
      password: ${REDIS_PASSWORD}   # resolved from infra/.env

server:
  port: 8080

management:
  endpoints:
    web:
      exposure:
        include: health,info
  endpoint:
    health:
      show-details: always

Running

# Start Docker infrastructure first
docker compose -f infra/docker-compose.yml up -d

# Apply database schema (once, after Docker is up)
docker exec -i iam-postgres psql -U iam_user -d iam_engine \
  < backend/auth-core/src/main/resources/db/migration/V1__init.sql

# Start the application
./mvnw spring-boot:run -pl backend/api-gateway
# Starts on http://localhost:8080

Health Check

curl http://localhost:8080/actuator/health
# Expected: {"status":"UP"} with db=UP and redis=UP

Test Configuration

Tests use H2 in-memory database instead of PostgreSQL:

# backend/api-gateway/src/test/resources/application.yml
spring:
  datasource:
    url: jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1
    driver-class-name: org.h2.Driver
  jpa:
    hibernate:
      ddl-auto: create-drop
  flyway:
    enabled: false

Redis is mocked in tests via @MockBean since it's not available in the test environment.