Technology and Digital TransformationCloud Computing

• Understanding Cloud-Native Applications: Cloud-native applications are designed to leverage elastic, scalable cloud infrastructure.
• 12-Factor App Methodology: Emphasizes practices such as one codebase per application, dependency management, and configuration storage in the environment.

• Making an app stateless so it can be easily scaled across multiple instances without session management issues.

• Adopt the 12-Factor principles:
• Use environment variables for configuration settings.
• Port-bind services to make them accessible through specific URLs or ports.
• Maintain parity between development and production environments.

• Convention over Configuration: Spring Boot minimizes configuration needed to set up a new application.
• Embedded Servers: The use of embedded servers (like Tomcat) simplifies deployment and reduces complexity.

• Creating a new Spring Boot application using the spring-boot-starter-web dependency to quickly set up a web server.

• Initialize a Spring Boot project:
• Use the Spring Initializr to generate a starter project.
• Add necessary dependencies directly in the pom.xml or build.gradle file.

• Health Checks and Metrics: Actuator endpoints provide essential metrics, health checks, and more.
• Custom Endpoints: Creating custom Actuator endpoints tailored to specific application needs.

• Enabling the /actuator/health endpoint to monitor the health status of the application.

• Enable Actuator in Spring Boot:
• Add the spring-boot-starter-actuator dependency.
• Customize endpoints in the application.properties (e.g., management.endpoints.web.exposure.include=health,info).

• Service Discovery with Eureka: Registering and discovering services dynamically.
• Configuration Management with Config Server: Centralized management of application configurations.

• Setting up a Eureka server and client to automatically discover and register services.

• Setup Eureka for Service Discovery:
• Add spring-cloud-starter-netflix-eureka-server to the server project and spring-cloud-starter-netflix-eureka-client to client projects.
• Configure the application.yml with necessary server URLs for registration.

• Circuit Breakers with Hystrix: Protecting systems from cascading failures through circuit breaking.
• Client-Side Load Balancing with Ribbon: Distributing load across multiple service instances.

• Implementing a Hystrix command to wrap a potentially failing call and provide a fallback method in case of failure.

• Use Hystrix for Fault Tolerance:
• Include the spring-cloud-starter-netflix-hystrix dependency.
• Annotate methods with @HystrixCommand and specify fallback methods.

• Message Queues with RabbitMQ: Decoupling services using message queues for asynchronous communication.
• Event Sourcing and CQRS: Storing state changes as events and separating read and write operations.

• Setting up a RabbitMQ message broker and configuring a Spring Boot application to send and receive messages.

• Integrate RabbitMQ:
• Add spring-boot-starter-amqp dependency.
• Configure connection settings in application.properties.
• Annotate listener methods with @RabbitListener.

• OAuth2 for Single Sign-On: Securing applications using OAuth2 protocol.
• Spring Security: Comprehensive security framework to handle authentication and authorization.

• Securing REST endpoints using Spring Security’s annotations and configurations.

• Implement Spring Security:
• Add spring-boot-starter-security dependency.
• Configure security settings in the SecurityConfig with @EnableWebSecurity.

• Unit Testing with JUnit: Isolating and testing individual units of code.
• Integration Testing: Testing interactions between multiple components or services.

• Writing a Spring Boot integration test using @SpringBootTest and MockMvc.

• Conduct Integration Tests:
• Use @SpringBootTest to load the full application context.
• Utilize MockMvc to perform HTTP requests and perform assertions.

• Containerization with Docker: Packaging applications in Docker containers for consistent deployments.
• Continuous Integration/Continuous Deployment (CI/CD): Automating build, test, and deployment processes.

• Creating a Dockerfile to containerize a Spring Boot application.

• Dockerize a Spring Boot App:
• Write a Dockerfile that specifies the base image and commands to build the application.
• Use Docker Compose for deploying multi-container applications.

• Deploying to Cloud Foundry: Using Cloud Foundry’s facilities to deploy and manage applications at scale.
• Service Bindings: Connecting applications to managed services like databases and message queues.

• Using the cf CLI to push a Spring Boot application to Cloud Foundry.

• Deploy to Cloud Foundry:
• Install the Cloud Foundry CLI (cf).
• Use cf push to deploy an app, specifying manifest details in manifest.yml.

Technology and Digital TransformationCloud Computing