gatete-bruno/3-tier

three-tier Blog-11

architecture is a software architecture pattern that divides an application into three separate logical layers, each responsible for specific functionalities.

These layers are:

Presentation Tier (or User Interface Tier): This tier is responsible for presenting information to the users and gathering user inputs. It typically includes user interfaces such as web browsers, mobile applications, or desktop applications. The presentation tier communicates with the other tiers to retrieve data and execute business logic.

Application Tier (or Business Logic Tier): Also known as the middle tier, this layer contains the business logic of the application. It processes and manipulates data, performs calculations, and implements the application's functionality. The application tier acts as an intermediary between the presentation tier and the data tier, translating user requests into operations on the data and vice versa.

Data Tier (or Data Storage Tier): This tier is responsible for storing and managing the application's data. It includes databases, file systems, or any other data storage mechanism. The data tier provides persistence for the application's data and is accessed by the application tier to retrieve or modify data based on user requests.

Why ?

The three-tier architecture separates concerns and promotes modularity, scalability, and maintainability in software applications. Each tier can be developed, deployed, and scaled independently, allowing for easier management and evolution of the system. Additionally, this architecture facilitates reusability of components and promotes a clear separation of concerns, making it easier to develop, test, and maintain the application over time.

Exploring Kubernetes: If you're new to Kubernetes, check out my previous blog post [link] for an introduction to Kubernetes and its core concepts.

Setting up Kubernetes Cluster: To get started, follow the steps outlined in my blog post [link] for a simple Kubernetes cluster setup using Kubespray.

Understanding Kubernetes Services: Kubernetes Services play a crucial role in enabling communication between pods. Learn about the different types of services and how they facilitate seamless communication within the cluster.

Deploying Frontend Web Service: We'll start by deploying the frontend tier of our application using Apache HTTP Server. Dive into the YAML configuration and learn how to define a Kubernetes Deployment for the frontend service.

Testing Frontend Deployment: Apply the configuration and verify the deployment by accessing the web server from any node's IP address using the NodePort service.

Deploying Backend Application Tier: Move on to deploying the backend application tier, tailored to our specific requirements. Create a Deployment configuration for the backend service and ensure its successful deployment.

Setting up Backend Database Tier: Enter the final phase by setting up the backend database tier using PostgreSQL. Learn about ConfigMaps, PersistentVolumes, and PersistentVolumeClaims to ensure data persistence and secure storage for the database.

Testing Database Connection: Validate the database connection by connecting to the PostgreSQL database from within a pod using the psql client.