What to consider in .NET Core / 5 / 6+ Projects

Welcome, perhaps your relatively new to .NET Core, you may come from Java, PHP, or even the older .NET Framework.

All too often I see devs, and architects that are not completely familiar with .NET Core implement solutions that are essentially already baked into .NET Core itself. They may have used .NET Framework in the past years ago, and use the same principles applied to .NET Core. This is not a good approach to take, for one it’s reinventing the wheel, usually with code that is less battle tested, and often not as extensible. It also requires extra maintenance and custom documentation, with less support.

Well here I aim to explain the core concepts in .NET Core’s base layers to help you get up to speed quickly. I am assuming you already know C# to some degree, and how it plugs into .NET in general. You also understand design patterns and understand how to write clean maintainable code.

Quick overview with .NET Framework to .NET Core

First off .NET Core != .NET Framework …. that’s right, while they share syntactical similarities, nuget, and tooling and so on, they are essentially completely different platforms.

• .NET Framework from .NET Framework 1 - .NET Framework 4.8
• .NET Core 1.0 - .NET Core 3.1 and now just .NET 5 / .NET 6 ….. etc

.NET Framework
Designed specifically for Windows OS and released around 2001. Requires Windows tooling such as Visual Studio for editing, and I.I.S for ASP.NET Web Servers, was the .NET ecosystem up until .NET Core come around.

• Closed source Proprietary framework
• Windows only development and runtimes (there were spinoffs such as Mono for other platforms, and various other runtimes)
• ASP.NET Minmum memory for a request was approx 26kb
• ASP.NET Extensibility was somewhat complex.
• Suited SOAP, WCF, XML techs

.NET Core
Re-architected from the ground up for new open cross platform developments. Released 2014

• Cross-platform development and runtimes
• Open source
• Open standards
• Highly configurable and extensible
• Command line tooling infrastructure
• Lighter, significant performance improvements
• Dependency Injection is first class principle
• Web Api minimum request memory ~2kb
• designed for modern development approaches such as Web Api’s, JSON, REST.
• Provided a command line tool dnx which was later changed to dotnet in later versions.

In essence, .NET 5/6/7+ is the current and future of .NET…… there is no point going back to the older .NET Framework unless legacy projects have no alternative

Core concepts, patterns, considerations for .NET Core/5+ apps

Item	Description
Abstractions	Define interfaces
Builders	- Define a pattern to build something
	- Web Host builders
	- Configuration Builders
Middleware	Defining Request / Response Pipelines
Configuration	Unlike .NET Framework, Configuration in .NET Core is incredibly flexible and simple at the same time. Very simple to extend and create new ConfigurationSource(s) and Providers, you can retrieve config from file(s), databases, environment, command line and access it consistently using IConfiguration or IOptions<T> patterns
Command line tooling	- dotnet provides access to built in compilation and runtime tooling, as well as custom built local and global tools
	- dotnet ef provides database migrations, updates and reverse engineering tooling
	- dotnet new command for scaffolding new solutions, projects, files. Creating custom templates.
	- dotnet tools for console based applications
Dependency Injection	Now a first class principle. Code by abstraction
Health Checks	Health checking multiple services, consider app, db, custom services etc
Localization	For localizing content according to a culture, different languages, time zones etc

Explicit Abstractions

Item	Description
IServiceCollection	- .NET’s Dependency Injection Service registration builder
IConfiguration	- .NET flexible overridable configuration system, gather config from multiple sources
IOptions<T>	- Strongly typed configuration suitable for injection based on .NET’s flexible configuration system
ILogger<T>	- Genericly typed class Logging suitable for class injection
ILoggingFactory	- Logging factory to create loggers
IDistributedCache	- Distributed caching such as Redis, Sql, Mem, etc
IHttpClientFactory	- Injectable factory for creating safe pooled HttpClients
IHealthCheck	- For a custom healthcheck to plugin to healthcheck system
IStringLocalizer<T>	- Simple string localization with OOTB functionality, and extendable