In this article, you will see a Web API solution template which is built on Hexagonal Architecture with all essential features using .NET Core.
Introduction
This is kick-off project which will have all essential things integrated to it. When we have to start with a new project, then we should think of business. When business requirement is ready, then we have to start focusing the business and we should be ready with basic / essential libraries.
We will see some important libraries order wise, which should be integrated to our project for kick-off.
Essentials Libraries/ Steps to be Ready for ASP.NET Core
- Application is implemented on Hexagonal architecture
- Web API
- Entityframework Core
- Expection handling
- Unit testing via NUnit
- Versioning
- Swagger UI
- Loggings — seriLog
- Health checks UI
- JWT authentication
What is Hexagonal Architecture
It is Architecture pattern which is introduced by Alistair Cockburn in 2005, which will solve problems in maintaining application. In traditional architecture, where we use to implement by Database centric architecture.
Hexagonal Architecture, or to call it properly, “Ports and Adapters pattern”, is driven by the idea that the application is central to your system. All inputs and outputs reach or leave the core of the application through a port that isolates the application from external technologies, tools and delivery mechanics.
Hexagonal Architecture is based on the inversion of control principle. It’s composed of domain concentric architecture where layers interface with each other towards the Domain (Entities/Classes).
Main benefit of Hexagonal architecture is plug & play, flexibility and de-coupling. In this approach, we can see that all the Layers are dependent only on the Domain layer.
Benefits of Hexagonal Architecture
- Plug & play: We can add or remove adapter based on our development, like we can replace Rest adapter with GraphQL or gRPC adapter. Rest all logic will be remain same.
- Testability: As it decoupled all layers, so it is easy to write test case for each components.
- Adaptability/Enhance: Adding new way to interact with application is very easy.
- Sustainability: We can keep all third party libraries in Infrastructure layer and hence maintenance will be easy.
- Database Independent: Since database is separated from data access, it is quite easy switch database providers.
- Clean code: As business logic is away from presentation layer, it is easy to implement UI (like React, Angular or Blazor).
- Well organised: Project is well organised for better understanding and for onboarding for new joinee to project.
Disadvantages of Hexagonal Architecture
- Domain layer will be heavy: Lots of logic will be implemented in Domain layer (sometimes called as Core layer).
- Bunch of layers: For implementing small application like CRUD operation, then too bunch of layers should be implemented.
Layers of the Hexagonal Architecture
In this approach, we can see that all the Layers are dependent only on the Core Layers.
Domain Api layer
Domain Api Layers (Core layer) is implemented in center and never depends on any other layer. It is contract for domain layer interaction(ports) so that primary and secondary adapters can implement the contract. This is also known and DIP or Dependency Inversion Principle.
Domain layer
Domain Layers (Business layer) which has business logic. and it is keep clean with no other dependencies.
Rest Adapter layer
Rest Adapter also known as left port’s adapter and primary adapter where we implement restful service (i.e., GET, POST, PUT, DELETE, etc.).
Persistence Adapter layer
Rest Adapter also known as right port's adapter and secondary adapter where we have implement Entity framework core which already implements a repository design pattern. DbContext will be UOW (Unit of Work) and each DbSet is the repository. This interacts with our database using dataproviders.
Bootstrap/Presentation Layer
This is final build of project, where it all begin.
Getting Started with Hexagonal Architecture
Step 1: Download and Install Visual Studio Extension from Project Template
Download and install Visual Studio extension from Microsoft marketplace.
Step 2: Create Project
Select project type as WebAPI, and select Hexagonal Architecture.
Step 3: Select Hexagonal Architecture project template
Select project type as Web API, and select Hexagonal Architecture.
Step 4: Project is ready
Step 5: Build and run application
Health check UI
Navigate to Health Checks UI https://localhost:44377/healthcheck-ui and make sure everything is green.
** Change port number according to your application.
Swagger UI
Swagger UI https://localhost:44377/OpenAPI/index.html
** Change port number according to your application.
What problem does this solution solve
App generator solution includes all essential libraries with best practice, which will helps quick start project. Developer can concentrate on Business requirement and build entities. This helps save lots of development time.
Below are some essentials libraries which is already included in project with best practice built on Hexagonal architecture.
- Entity Framework Core
- Dependency injection
- Logging-Serilog
- Authentication
- Swagger/ OpenAPI
- Error handling
- Unit testing via NUnit
- Versioning
How does this help someone else
This solution helps for developer who can save development time and concentrate on Business module. And if he/she with less experience then it helps to maintain best practices in project (like clean code).
How does the code actually work
This is project template which is hosted in marketplace.visualstudio.com. Download this extension from marketplace and install in your visual studio. While creating project select this template.
Conclusion
In this article, we have seen what is Hexagonal Architecture and the difference between Design, Architecture pattern and Architecture Style. Project template will help us to quick start application.