⬅️ Back to Architecture

Configuration Overview

This section documents how the Inventory Service is configured through Spring Boot, property files, environment variables, and Java configuration classes. Configuration drives behavior across environments (local, test, production) without code changes.

What is Configuration?

In Spring Boot, configuration means:

  • Property files (application.yml, application-prod.yml, etc.) define environment-specific values
  • Java classes with @Configuration and @ConfigurationProperties create beans and bind properties
  • Environment variables override properties at runtime (highest priority)
  • Profiles select which property files and beans are active

Configuration Layers

Environment Variables (highest priority)
    ↓
application-{profile}.yml
    ↓
application.yml (base defaults)
    ↓
Java Configuration Classes (@Configuration)
    ↓
Default Values (lowest priority)

Directory Structure

Configuration sources are organized across two main areas:

Property Files (src/main/resources/)

src/main/resources/
├── application.yml              # Base config, shared across all environments
├── application-prod.yml         # Production overrides
├── application-test.yml         # Test/CI overrides
└── application.properties       # App name (used by Spring Boot)

Java Configuration (src/main/java/.../config/)

src/main/java/com/smartsupplypro/inventory/config/
├── AppProperties.java           # Custom app properties (demo mode, frontend URLs)
├── SecurityConfig.java          # OAuth2 and method-level security setup
├── SecurityAuthorizationHelper.java  # Authorization rules for endpoints
├── SecurityEntryPointHelper.java     # Authentication failure handling
├── SecurityFilterHelper.java         # API vs browser request detection
└── SecuritySpelBridgeConfig.java    # SpEL bridge for security expressions

Configuration by Topic

Topic File Purpose
Spring Config Classes spring-config-classes.md Beans, mappers, security setup
Property Files application-config-files.md YAML/properties structure
Profiles & Environments profiles-and-environments.md How profiles control behavior
Database & Oracle database-and-oracle-wallet.md Connection, wallet, credentials
Logging & Monitoring logging-and-monitoring.md Log levels, output paths
Feature Flags feature-flags-and-demo-mode.md Demo mode, custom flags
External Services external-services-and-secrets.md OAuth2, secret injection

Common Configuration Tasks

Running with Different Profiles

# Local development (default, no profile)
mvn spring-boot:run

# With test profile (H2 in-memory DB)
mvn spring-boot:run -Dspring-boot.run.arguments="--spring.profiles.active=test"

# With prod profile (Oracle DB)
mvn spring-boot:run -Dspring-boot.run.arguments="--spring.profiles.active=prod"

Setting Environment Variables

Configuration priorities (highest to lowest):

# 1. Environment variables override everything
export DB_URL="jdbc:oracle:thin:@..."
export APP_DEMO_READONLY="true"

# 2. Profile-specific files (application-prod.yml)
#    Use these for profile defaults

# 3. Base config file (application.yml)
#    Use for shared defaults

# 4. Java defaults in code
#    Use as fallback

Key Environment Variables

These are the primary knobs for runtime configuration:

Variable Default Purpose
SPRING_PROFILES_ACTIVE (none) Which profile(s) to activate
DB_URL (required in prod) Oracle database URL
DB_USER (required in prod) Database username
DB_PASS (required in prod) Database password
APP_DEMO_READONLY true Enable read-only demo mode
APP_FRONTEND_BASE_URL https://localhost:5173 Frontend redirect URL for OAuth2
APP_ADMIN_EMAILS (empty) Comma-separated admin email list
SPRING_SECURITY_OAUTH2_CLIENT_REGISTRATION_GOOGLE_CLIENT_ID (required) Google OAuth2 client ID
SPRING_SECURITY_OAUTH2_CLIENT_REGISTRATION_GOOGLE_CLIENT_SECRET (required) Google OAuth2 secret

How Configuration Flows Through the App

Environment Variables
        ↓
    Spring Boot loads properties
        ↓
    @ConfigurationProperties classes bind values
        ↓
    @Configuration classes create beans
        ↓
    Controllers & Services @Autowired inject beans
        ↓
    Application behavior adapts to config

Example: Demo Mode

  1. Config value: APP_DEMO_READONLY=true (environment variable)
  2. Binding: AppProperties.isDemoReadonly field receives value
  3. Bean creation: SecurityConfig uses props.isDemoReadonly() when building filter chain
  4. Authorization: SecurityAuthorizationHelper.configureAuthorization() permits GET requests without login
  5. Result: Public can read inventory without login; writes still require admin role

Configuration Profiles Used

Profile Database Use Case When Active
(default) PostgreSQL/Oracle Local dev (requires .env setup) When SPRING_PROFILES_ACTIVE is not set
test H2 in-memory CI/CD, unit tests In test environments
prod Oracle Production (Fly.io, cloud) SPRING_PROFILES_ACTIVE=prod

⬅️ Back to Architecture