Profiles

🔍 What Is It?

Spring Profiles provide a way to segregate parts of your application configuration and make it only available in certain environments.

Profile-specific config files:

• →application.yml — defaults for all profiles
• →application-dev.yml — dev overrides
• →application-test.yml — test overrides
• →application-staging.yml — staging overrides
• →application-prod.yml — production overrides

Profile-specific beans:

• →@Profile("dev") — only register this bean in dev
• →@Profile("!prod") — register in all profiles except prod
• →@Profile({"dev", "test"}) — register in dev and test

Activation:

• →SPRING_PROFILES_ACTIVE=prod (environment variable — production)
• →--spring.profiles.active=dev (command line)
• →spring.profiles.active=dev (application.properties — never for prod)
• →@ActiveProfiles("test") (tests)

🎯 Why Do We Need It?

Without profiles, you'd either:

• →Have one config file with if/else logic (messy)
• →Manually edit properties before each deployment (error-prone)
• →Have different code branches per environment (unmaintainable)

Profiles provide a clean, declarative way to manage environment differences.

🏗️ What Happens in Real Projects?

Standard enterprise profile setup:

• →dev: H2 in-memory DB, DEBUG logging, all Actuator endpoints exposed, hot reload
• →test: Testcontainers or H2, INFO logging, no external services
• →staging: Real database (staging), INFO logging, same config as prod
• →prod: Production database, WARN logging, minimal Actuator exposure, SSL

⚙️ How It Works

Spring loads application.yml first, then application-{profile}.yml. Profile-specific properties override defaults. Multiple active profiles are supported — properties from later profiles override earlier ones.

💻 Example

Profile Configuration — Environment-specific configuration and profile-specific beans.

# application.yml (defaults)
spring:
  application:
    name: order-service
server:
  port: 8080
logging:
  level:
    root: INFO

---
# application-dev.yml
spring:
  datasource:
    url: jdbc:h2:mem:devdb
    driver-class-name: org.h2.Driver
  jpa:
    hibernate:
      ddl-auto: create-drop
    show-sql: true
  h2:
    console:
      enabled: true
logging:
  level:
    com.company: DEBUG
    org.hibernate.SQL: DEBUG
management:
  endpoints:
    web:
      exposure:
        include: "*"

---
# application-prod.yml
spring:
  datasource:
    url: jdbc:postgresql://${DB_HOST}:5432/${DB_NAME}
    username: ${DB_USERNAME}
    password: ${DB_PASSWORD}
  jpa:
    hibernate:
      ddl-auto: validate
logging:
  level:
    root: WARN
    com.company: INFO
management:
  endpoints:
    web:
      exposure:
        include: health,info,metrics

🤔 Common Confusions

🚨 Common Production Issues

✅ Best Practices

🏛️ Architect's Note

💬 Frequently Asked Questions

🎯 Key Takeaways

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