Building a .NET Cloud Application

Introduction

In my first two articles, we first looked at the four common types of .NET applications we may find out in the field. We briefly discussed these four types of applications and then in the second article, we looked at the design and architecture at a high level which would apply to all these applications in general terms. Next, we build the first type of application, the .NET desktop application. After that we built the .NET web application. Today, we will look to move this web application to the cloud.

Requirements for building this application

Unlike the previous two articles where we built a .NET desktop and .NET web application, in this article we will not be building an application from scratch. Instead, we will be moving the .NET web application built in the previous article to the cloud. Hence, we will be deploying the application to Microsoft Azure. The requirements for this article are as below,

A Microsoft Azure account

You can easily sign-up for the one-month free Microsoft Azure account to implement the solution in this article. However, if you have already used this one free month, you can easily use a “Pay as you go” subscription as I have done so to deploy this application to the cloud.

The Data Source

Let us start by setting up the SQL database in Microsoft Azure. Log into your Microsoft Azure portal account and you will see the first screen as below,

If you do not have a current subscription, then to add a new one, select subscriptions and you will be directed to a new page as below,

Here I selected the option “Pay-As-You-Go” and signed up for this. The name of this subscription is also “Pay-As-You-Go”. After that we see the Microsoft Azure main page as below,

Here, we will start by creating a database using the “SQL databases” option.

This is a PAAS (Platform-As-A-Service) feature. As you can see there are no existing databases currently in our subscription. We start to create a new database,

Here we create a new resource group called “EmployeeCloud”. We will place all resources in this resource group. This will make it easy to maintain all resources. We name the server “munibclouddb” and place it in the “East US” region. The database is named “EmployeeDB”. We also use the most basic “Compute + storage” tier which is “Basic” and this gives us a storage of 1GB. We also setup the administrator account for the server (munibadmin).

Once created, we see the below,

Here we see that two resources have been created, A SQL sever and SQL database. Next, in order to maintain this database server from our local machine, we need to open the firewall to it from our machine.

As seen above, select the option “Firewalls and virtual networks” and add your Client IP address to the rules and click “Save”. You can now access this database server from SQL Server Management Studio on your local machine.

Next, go to the option “Query editor (preview)” and create the table used in the previous article as below,

CREATE TABLE [dbo].[Employees](
[Employee_ID] [int] IDENTITY(1,1) NOT NULL,
[First_Name] [nvarchar](50) NOT NULL,
[Last_Name] [nvarchar](50) NOT NULL,
[Date_Birth] [smalldatetime] NOT NULL,
[Street_Address] [nvarchar](100) NULL,
[City] [nvarchar](50) NOT NULL,
[Province] [char](2) NOT NULL,
[Date_Joining] [smalldatetime] NOT NULL,
[Date_Leaving] [smalldatetime] NULL,
CONSTRAINT [PK_Employees] PRIMARY KEY CLUSTERED
(
[Employee_ID] ASC)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

also, add a new record using the below query,

INSERT INTO [dbo].[Employees] (First_Name, Last_Name, Date_Birth, Street_Address, City, Province, Date_Joining)
VALUES ('John', 'Doe', '1980-10-01', '100 Street West','Toronto','ON','2020-01-15')

Now, if we open the database in SSMS we see the below,

At this point, we have created our SQL server and database in Microsoft Azure. We will now proceed to setting up the data access Web API application.

The Data Access Layer

The data access layer application would be deployed as a Web App under the Azure App services. This is also a PAAS solution. We will be deploying the “EmployeeDALWebApi” application created in the previous article here.

We navigate to the “App Services” main page as below,

Here we create a new “App Service” as below,

Most of the above is self-explanatory. I would just like to mention a few things. We will use the “.NET Core 3.1” runtime stack as our application was developed using the “.NET Core 3.1” target. We will also deploy our application on a “Windows” based machine, although we could also have used a Linux one. The Windows Plan used is “ASP-EmployeeCloud-b88e” which could be thought as the app server. We will be adding the front end MVC core application to this same plan. Finally, the Sku and size used is the Free F1 tier.

Once created, we see the below,

Now, we see that a “App Service Plan” and “App Service” have been created.

The next step is to publish our application to the App service created in Microsoft Azure. We open the solution we created in the previous article, select the “EmployeeDALWebApi” project and select “publish” as below,

Once we click “Publish”, our application will be published to the cloud. We can verify as below,

Now, before we can test the Employee controller, we need to open the firewall of the database to the app we just created. This is done as below,

From the “Database server”, set “Allow Azure services and resources to access this server” to “Yes” and save.

Next, we need to update the connection string for the app. Copy the connection string from the “Overview” page of the database and then select the “App Service Edito (Preview)” from the app service as below,

Once, this step is complete, the data access layer application is now fully deployed, and we can verify from the browser as below,

Next, we move to the business logic layer and Presentation layer.

The Business Logic Layer and Presentation Layer

The business logic layer will be deployed as part of the presentation layer. We will create a new web app service in Microsoft Azure and deploy the “EmployeeWebApp” application, created in the previous article to it. This will serve as the business and presentation layer for the solution.

Let us start by creating a new Web App service as below,

Once the web app service is created, we are ready to deploy the MVC core application to it. However, there is one small change needed. We need to update the base address of the web api service (to point to the service just deployed in the cloud) as below,

Please note that I have kept the base address in the code. However, this can be moved into the configuration file of the MVC core application.

Next, we publish the “EmployeeWebApp” as below,

Once published, the deployment is complete, and we can navigate to the employee controller in the front-end application as below,

Finally, there is one more thing I would like to mention here. There are numerous ways to secure the connection sting like using Azure Vault etc. However, for now, we will simply move this to the configuration of the Web API application as below,

Now, the connection string will be read from here we can set it to an empty string in the “appsettings. json” file.

The complete list of all resources used to setup the solution is below,

Remember to delete the “Resource group”, once you are done with this solution in order to avoid costs.

Summary

In this article, we covered the simple process to move an MVC core and Web API core application to the cloud into Microsoft Azure. As you can see this is a very simple process. There are many things that can be done to extend this application for scalability, add application usage instrumentation etc. and I will leave these to you to further investigate. In the next article, we will look to build a mobile application front end which will communicate with the web API we have created.