.NET 5 REST API Tutorial: 01 Getting Started

 This is the first part of my .NET 5 REST API Tutorial. You will learn: • The scenario to be used across the tutorial • How to create a .NET 5 Web API project from scratch • How to use VS Code for building and debugging the project • How to trust the development certificate • How to use Swagger UI to interact with the API 

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a rest API allows your app or system to

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expose its functionality to multiple

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types of clients both inside and outside

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of your network including clients across

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the internet this is what you would use

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if you wanted to write a program to

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collect data from say Twitter Yahoo

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finance or even NASA if you're looking

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into building your own res API and

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you're considering the net platform for

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it please stay with me as I show you how

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to do this end to endend using the

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latest Innovations provided by Net 5

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I hope you enjoy

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it in the first part of this tutorial

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you're going to learn the scenario to be

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used across a tutorial how to create a

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net 5 web API project from

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scratch how to use Visual Studio code

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for building and debugging the project

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we're going to work

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on how to trust the development

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certificate installed by Net 5 and

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that's going to be needed for https

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access and how to use Swagger UI to

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interact with the

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API to follow the tutorial you're going

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to need a few things including the net 5

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SDK Visual Studio

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code and some basic understanding of the

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c c

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language now let's talk about the

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scenario that we're going to be using uh

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as a domain for this tutorial so let's

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imagine that we have some sort of a

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catalog system uh and that we have a

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bunch of items available in it so in

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this sense uh like I am uh video video

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gamer so I like to think of these items

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as items that I would use within a video

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game so items like potions uh sorts

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Shields and stuff like that right so

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that's a system that we have in place it

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has a catalog and uh of course we're

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going to have users that are going to be

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would like to manage this catalog uh via

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their their browser right they have a

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browser they want to manage this catalog

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of items

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somehow so and things that they would

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they would like to do is well uh how are

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we going to create items in the catalog

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H how can we retrieve uh the the list of

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items currently available in this

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catalog how can we update properties uh

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of of the items and how can we delete

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items in this catalog so as it is today

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h we do have the catalog available but

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we lack uh or we don't have uh a way to

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expose this catalog to the Internet so

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that people can just go ahead and manage

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it from the browser so that's where

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we're going to introduce a res API for

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this catalog and uh during this tutorial

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we're going to see how to build this R

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API from scratch using Net

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5 so here we are in Visual Studio code

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and the first thing we're going to do is

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open a brand new

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terminal and in this terminal we're just

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going to switch to the directory uh

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where we're going to create our project

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and to create a project we're going to

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be using the net

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CLI uh so to do that we're just going to

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say dot net new and the type of project

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that we want that we want to create for

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a rest API that's going to be web

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API and the name of the project is going

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to be catalog hit

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enter and that creates generates all the

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files based on the web API template so

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now I'm going to open that folder that

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got generated

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catalog and uh as you open as usual as

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you open a net project in Vis Studio

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code it will prompt you to add a few

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additional files for building and

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debugging the project so I'm going to

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say yes and those files get generated

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under that vs code so on the left side

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you can actually see all the generated

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files and let's take a quick look at at

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each of these

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files as a quick lab around so the first

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file we're going to look look at is the

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cspr file and this file uh is used this

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is called the project file and this is

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used to declare how we're going to build

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this project in this case we're saying

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that we're going to be using the net web

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SDK uh to build the project which

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includes a bunch of tools and tasks uh

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to specifically designed for web kind of

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projects the next interesting thing will

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be the target framework H monitor or

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Target framework which in our case is

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net five uh the target framework defines

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uh the API are face or what kind of apis

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are going to be available to your

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project in this case net five is

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perfectly good for us and the next thing

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is going to be a bunch of nou packages

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that we're not going to be diving into

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right now but those are just

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dependencies that we already acquir um

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on this project close that and the next

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file that I'm going to take a look is

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just program CS program CS is what we

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call the entry point of the application

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and what this will do is just uh pretty

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much uh raise or stand up the host that

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I mean the yeah the process that's going

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to become the host of our progam and it

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also declares a bunch of defaults and it

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also sets up what it what we call the

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start app uh startup class for our

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project so let's actually go to Startup

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and's see what's going on there uh

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really the main things in startup are

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that uh we have this property called

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configuration uh that we receive as part

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of the startup Constructor and this you

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can use anytime you need to read some

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configuration information from multiple

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sources like from environment variables

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or files different kinds of files or a

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bunch of other places configuration that

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you don't want to hardcode into your

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service the next interesting method is

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configure services and this is the the

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place where you would uh register all

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the services that you're going to be

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using across your application we'll talk

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about this later on in this video and

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the last interesting piece is the

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configure

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method this is what we configure what we

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call the

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ER the pipeline right the request

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Pipeline on asp.net and so this just

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defines a bunch of what we call middle

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Wares which are a additional components

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that will execute uh before uh your um

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before your your controller or your your

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code actually executes so each of the

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each of these can execute a uh as a

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request comes into H into the aset

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process and from there all the way into

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when your code executes uh but we're not

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going to be exploring this part in this

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video um a couple of other things are uh

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so we have a weather forecast so this is

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a a model that gets autogenerated for

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the sample application here just have a

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few very simple properties here and uh

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alongside this uh this model there's a

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controller now the controller in asp.net

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is just uh pretty much the class that

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handles the routes uh yeah pretty much

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the routes that uh your service exposes

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right but we're not going to be using

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this in this video so let's not dive too

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much into

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that a few other files upsetting Json

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this is where you can declare

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configuration uh that's going to be that

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you don't want to use hardcode into uh

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your into your your program your your

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source code uh so and right now it just

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has some configuration for login and the

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host that are allowed in the app there's

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also a variant of appsettings Json which

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is upsetting development Json uh so

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developing I mean the fact that it that

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says does say up settings. development.

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Json means that when we're running in

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development environment uh these

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settings will take precedence on top of

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the app settings Json so you could have

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a bunch of these app settings files for

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each of your uh environment like

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production test integration all all of

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these environments um now if we talk

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about environments uh may be a good time

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to take a look at the file generated

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that vs code uh which are task Json and

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launch launch Json task Json is just a

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file that declares the tasks uh this is

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a a key concept on Vis Studio code you

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can declare tasks and and a task is can

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be a bunch of things and in our case the

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most interesting task is the fact that

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we want to just run the net build

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command so net build which is going to

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be used for building our

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code and uh in terms of launch ad Json

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this is the file that controls what is

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going to be launch or executed and when

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we do like an F5 or when we start

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debugging the code in this case it's

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already pointing to the right dll for

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start to start

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debugging lastly uh we also have launch

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settings at Json and really the only

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interesting part here that that I'd like

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to you to take a look is the application

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URL uh here we are defining the URLs uh

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URLs in for our application uh in which

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case in this case we're saying we're

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going to be serving our our our server

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uh in a local host 5,000 and for the

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htps version we're reserving it which is

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going to be the default version uh is

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going to be

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50001 we're also declaring the actual H

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cord environment environment variable uh

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and we setting it as development and

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so uh Al to in Vis Studio code this is

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not the actual one that's been honored

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the one that will is going to be honored

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is in lunch Json uh as you see over here

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this is the one that takes presentent if

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stud cover so so that's good um what we

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want to do now is actually to test this

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this uh project just to make sure that

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everything is running as expected so

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what I'm going to do is I'm going to

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switch to the theog hub over here let me

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expand this a little bit and so what I'm

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going to do is just click and start

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debuging let's see what happens

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all right so browser pops up and then if

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you're getting this page here what it

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means uh it's Prett normal it means that

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uh we don't have uh the self-signed

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certificate that comes with net it has

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not been H trusted right and so and

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there's a very simple way to go around

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decision and to properly trust the

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certificate that comes with net so let

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me actually just close this and stop and

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let's switch back to the terminal the

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actually let me open a new terminal here

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yeah there it

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is so in order to trust the certificate

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that comes bundled with the net SDK H

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what you have to do is just

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type net

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defert

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https

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trust when you run this is you're going

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to get this popup uh asking you to

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confirm that you actually want to trust

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thater I'm going to say yes and then uh

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that pretty much should do it so I'm

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going to uh run it

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again let's see what we

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get all right so yeah so we still are

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not getting pretty much anything here

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but we are not seeing any trust issue

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anymore now if you actually want to see

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something meaningful here although it

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doesn't matter too much for us at this

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point what you can do is just go to

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Swagger and then you're going to get

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this this nice UI so this is what we

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call Swagger or also open API

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specification uh so this is a component

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that's is bundled now with Net 5 uh so

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you don't have to do anything to make it

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available as you saw we did nothing uh

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so it's just there uh in the/ Swagger

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URL and what this does is allows you to

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uh easily uh describe all the operations

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all the actions all the routes that are

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available in your API and allows you to

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also interact with them easily so for

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example if I just go to the get route

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and I click H try it out click execute

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it will go ahead and run it and we can

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see already some results for that

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route and then one thing that that I

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like to do uh as I work on these

12:25

projects is to uh really not uh open a

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browser every single time that that I

12:30

run the project uh so let let's actually

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switch a little bit the behavior of BS

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code so that we'll just keep this window

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open and then uh anytime we just hit a

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five or hit run uh it will not open more

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windows so to do that I'm going to stop

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here and we can go to launch the Json

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and close

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this the only thing that you have to do

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is just remove the server ready action

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section here

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here and that's pretty much it if I run

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again and by the way you can do this by

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just pressing a

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F5 which I'll do right now

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F5 that starts the host as you can see

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but we did not it did not open any more

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windows which is fine because we have

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the browser ready to go right

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there then the last thing that I like to

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do in terms of a project setup is to

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simplify how we build our project in

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Visual Studio code so for that let me

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minimize this and go back to visual

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studio code stop this close that what

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I'm going to do is to go to Tas adjacent

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and the only thing that I'm going to do

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is uh to add this little section here

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under the build task uh which is uh just

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the what we call the group which is kind

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buil and it says it's Default true what

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this does is that allows us to easily

13:59

build a project so now I can go to let

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me just save this saved I can go to uh

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terminal room build tasks and it

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immediately builds um without that we it

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will just have pop up yet another menu

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to do the build I can also now do

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control shift B and it will do the same

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thing so yes that just spits up our

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build

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situation so that's it for this video in

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the next one we're going to be

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introducing the domain entity which is

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item uh for this um for this service and

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also we'll introducing our repository

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class which is the one that's going to

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be in charge of both getting and uh

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persisting um the the items are going to

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be created across the service so yeah I

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hope this was useful and uh yeah if you

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like it uh please consider hitting the

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like button and don't forget to

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subscribe uh so that you know when I

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publish any new videos uh thanks a lot

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for watching and I'll see you next time