Welcome to the TechTalk hands-on lab! This lab is designed to guide you through three crucial aspects of modern software development: Resilience, CI/CD workflows, and Observability. By the end of this lab, you’ll have hands-on experience with Resilience4j in Java, setting up a GitHub workflow, and implementing observability with Prometheus.

This lab is divided into three sections:

1. Java Resilience4j
2. GitHub Workflow
3. Prometheus Observability

You should complete these sections in the order presented. Each section builds on the concepts learned in the previous one, providing a comprehensive understanding of resilience and observability in software development.

In this section, you’ll work with an existing Java application that demonstrates how to implement resilience patterns using the Resilience4j library. Resilience patterns like Circuit Breaker, Rate Limiter, and Retry are essential for building robust applications that can handle failures gracefully.

Key Objectives:

• Integrate Resilience4j into the Java application.
• Implement Circuit Breaker, Rate Limiter, Time limiter, and Retry patterns.
• Test the resilience features and understand their impact on application stability.

Once you complete the hands-on exercises in this section, you can move on to the next topic, where you'll automate the deployment and testing of this resilient application using GitHub workflows.

The second part of this lab focuses on Continuous Integration/Continuous Deployment (CI/CD) using GitHub Actions. Here, you will learn how to automate the build, test, and deployment processes of your Java application.

Key Objectives:

• Set up a GitHub Actions workflow to automate the build and test process.
• Integrate the Resilience4j application with a CI/CD pipeline.
• Automate the deployment process to ensure that the application is always up-to-date with the latest changes.

After mastering the GitHub workflow, you'll be ready to implement observability in the deployed application using Prometheus, which is the final part of this lab.

In the final section, you'll integrate Prometheus for observability, which is crucial for monitoring the health and performance of your application. Observability allows you to understand the internal state of your application based on the data it generates, which is vital for maintaining resilient and reliable services.

Key Objectives:

• Integrate Prometheus with the Java application.
• Set up metrics collection to monitor application performance.
• Visualize the data in Grafana to gain insights into the application's behavior.

By the end of this lab, you will have a robust Java application equipped with resilience patterns, automated CI/CD workflows using GitHub, and comprehensive observability through Prometheus. Each section is designed to build on the previous one, so be sure to complete them in the order provided.

Good luck, and enjoy the hands-on experience!

For more detailed instructions and specific configuration steps, please refer to the individual guides provided in each section.