Skip to main content

.Net5 Web API Managing Files Using Azure Blob Storage

In this article, we are going to understand the different file operations like uploading, reading, downloading, and deleting in .Net5 Web API application using Azure Blob Storage.

Azure Blob Storage:

Azure blob storage is Microsoft cloud storage. Blob storage can store a massive amount of file data as unstructured data. The unstructured data means not belong to any specific type, which means text or binary data. So something like images or pdf or videos to store in the cloud, then the most recommended is to use the blob store.

The key component to creating azure blob storage resource:

Storage Account:-
A Storage account gives a unique namespace in Azure for all the data we will save. Every object that we store in Azure Storage has an address. The address is nothing but the unique name of our Storage Account name. The combination of the account name and the Azure Storage blob endpoint forms the base address for each object in our Storage account. For example, if our Storage Account is named as 'myazurestorageaccount' then the base address will be like 'https://myazurestorageaccount.blob.core.windows.net'.

Containers:-
The containers are like folders in the file system. So storage account can have an unlimited number of containers. Inside each container can have an unlimited number of blobs.

Blobs:- 
Azure gives 3 types of blobs:
  • Block Blobs - Block of data managed individually. Most recommended for file uploading.
  • Append Blobs - Contains Block of data but with append operation.
  • Page Blogs

Create Azure Blob Storage In Azure Portal:

To consume any azure service we have to signup for the Azure portal, an additional bonus of the azure portal is users can use most of the service with free subscriptions. The free subscription is very handy for developers to learn about the azure service.

On the Azure portal dashboard page click on 'Create a resource'.

Search for 'Storage Account' and select to create.

Fill 'Create Storage Account' form.
  • 'Resource group' - enter the name of the resource group. Resource groups are just separators or wrappers.
  • 'Storage account name' - enter the unique name and this name will be used for creating the base address.
  • 'Location - you can select the default or choose your nearest location value.
  • 'Performance' - chose your preferred option(for free subscription go for the 'Standard' option)
  • 'Account Kind' - 'StorageV2(general purpose v2)' is the recommended option.
  • 'Replication' - chose your preferred option or select the default option.
Then remaining tabs you can skip or chose for creating the Storage Account.

Once storage created. In the left side menu under 'Blob Service' select 'Containers' then click on Create new container which opens a form for creation.
Inside of the 'New Container' form, enter your Container name and then select option 'access level' for the container.

Now while creating the container I'm assigning access level 'anonymous read access for container and blob' which gives permission to access the blobs with the domain address directly.


Create A .Net5 Web API Application:

Let's create .Net5 Web API application to implement our demo on Azure Blob Storage. The most recommended IDEs are Visual Studio 2019(Version 16.8.* supports .Net5) or Visual Studio Code.

Install Azure Blob .Net Packge:

Microsoft provides a .Net library to communicate with the Azure Blob Storage.
Package Manager:
Install-Package Azure.Storage.Blobs -Version 12.8.0
.Net CLI
dotnet add package Azure.Storage.Blobs --version 12.8.0

Add Azure Storage Account ConnectionString:

So to consume Azure Blob Storage into our Web API application we need to use 'ConnectionString' to establish a secured connection.

In Azure Storage Account, left-hand side under settings select 'Access Keys' menu and it will displays 'key1' and 'key2' access keys. We can choose any one connection string into our Web API application.

Now add the anyone connection string into the 'appsettings.Development.json' file.
appsettings.Development.json:
"ConnectionStrings": {
    "AzureBlobStorage":"your_azure_connection"
}

Register BlobServiceClient:

In a startup.cs file needs to register the 'Azure.Storage.Blobs.BlobServiceClient' so that it can be injected throughout our application where ever we need it. BlobServiceClient needs our azure connection string so we need to pass it as well.
Startup.cs:
services.AddScoped(_ => {
  return new BlobServiceClient(Configuration.GetConnectionString("AzureBlobStorage"));
});

Create API Endpoint To Upload Files To Azure Blob Storage:

Let's create a payload model for our upload API.
Models/FileModel.cs:
using Microsoft.AspNetCore.Http;

namespace AzureBlob.Api.Models
{
    public class FileModel
    {
        public IFormFile ImageFile{get;set;}
    }
}
  • The 'Microsoft.AspNetCore.Http.IFormFile' type can read the stream of file data from the client upload files.
Create a contract file like 'IFileManagerLogic.cs' which contains all abstract methods for file management for our sample. As the first step write an abstract method for file upload.
Logics/IFileManagerLogic.cs:
using System.Threading.Tasks;
using AzureBlob.Api.Models;

namespace AzureBlob.Api.Logics
{
    public interface IFileManagerLogic
    {
        Task Upload(FileModel model);
    }
}
Create an implementation file like 'FileManagerLogic.cs' which will implement all abstract methods of 'IFileManagerLogic.cs'.
Logics/FileManagerLogic.cs:
using System.Threading.Tasks;
using Azure.Storage.Blobs;
using AzureBlob.Api.Models;

namespace AzureBlob.Api.Logics
{
    public class FileManagerLogic: IFileManagerLogic
    {
        private readonly BlobServiceClient _blobServiceClient;
        public FileManagerLogic(BlobServiceClient blobServiceClient)
        {
            _blobServiceClient = blobServiceClient;
        }

        public async Task Upload(FileModel model)
        {
            var blobContainer = _blobServiceClient.GetBlobContainerClient("upload-file");

            var blobClient = blobContainer.GetBlobClient(model.ImageFile.FileName);

            await blobClient.UploadAsync(model.ImageFile.OpenReadStream());
        }
    }
}
  • (Line: 10) Injecting 'Azure.Storage.Blobs.BlobServiceClient'.
  • (Line: 15-22) Azure blob storage file uploading logic.
  • (Line: 17) The 'GetBlobContainerClient' create the instance of the 'BlobContainerClient'. To this method, we need to pass our container name that was created in the Azure. In my sample, my container name is "upload-file".
  • (Line: 19) The 'GetBlobClient'  method creates the instance of the 'BlobClient'. To this method, we need to pass the image name, this name will be given for our uploaded image to the Azure Blob Storage.
  • (Line: 21) The 'UploadAsync' method will upload our file stream to the Azure Blob Storage.
Now register our 'IFileManagerLogic' and 'FileManagerLogic' into the Startup.cs file.
Startup.cs:
services.AddScoped<IFileManagerLogic, FileManagerLogic>();
Create a controller like 'ImageController.cs', inside of it add action method for uploading the file.
Controllers/ImageController.cs:
using System.Threading.Tasks;
using AzureBlob.Api.Logics;
using AzureBlob.Api.Models;
using Microsoft.AspNetCore.Mvc;
namespace AzureBlob.Api.Controllers
{
    [ApiController]
    [Route("[controller]")]
    public class ImageController : ControllerBase
    {
        private readonly IFileManagerLogic _fileManagerLogic;
        
        public ImageController(IFileManagerLogic fileManagerLogic)
        {
            _fileManagerLogic = fileManagerLogic;
        }

        [Route("upload")]
        [HttpPost]
        public async Task<IActionResult> Upload([FromForm]FileModel model)
        {
            if (model.ImageFile != null)
            {
               await  _fileManagerLogic.Upload(model);
            }
            return Ok();
        }
    }
}
  • (Line: 13) Injected 'IFileManagerLogic'
  • (Line: 18-27) Action method for uploading the file. The attribute '[FromForm]' to read the file data from our form data that's going to be posted by the client.
Run the application and use the swagger UI to upload the file.
On successful file upload then go to our azure portal dashboard and then go to our Azure Blob Storage and then go to the container that we used in c# code there we can see our uploaded file stored as a blob.

Endpoint To Fetch Image From Azure Blob Storage:

One way to access the image from the Azure Blob Storage is accessing directly with the Azure base address.
Another way is from the Web API endpoint to read a stream of the image from the Azure Blob Storage. First, let's create an abstract method like 'Get(string fileName)' in 'IFileManagerLogic.cs'.
Logics/IFileManagerLogic.cs:
Task<byte[]> Get(string imageName);
Now let's implement logic to fetch the stream of data from the Azure Blob Storage in 'FileManagerLogic.cs'.
Logics/FileManagerLogic.cs:
public async Task<byte[]> Get(string imageName)
{
	var blobContainer = _blobServiceClient.GetBlobContainerClient("upload-file");

	var blobClient = blobContainer.GetBlobClient(imageName);
	var downloadContent = await blobClient.DownloadAsync();
	using (MemoryStream ms = new MemoryStream())
	{
		await downloadContent.Value.Content.CopyToAsync(ms);
		return ms.ToArray();
	}
}
  • (Line: 1) The 'Get' method expects the file name as an input parameter. The return type for this method is an array of byte data.
  • (Line: 3) Creating the instance of 'BlobConainer' by configuring our container name like 'upload-file'.
  • (Line: 5) Creating the instance of  'BlobClient' by configuring our image file name.
  • (Line: 6) The 'DownloadAsync' method communicates with the Azure Blob Storage and downloads our image from the specified container.
Create an action method to fetches the image by the name as an input parameter.
Controllers/ImageController.cs:
[Route("get")]
[HttpGet]
public async Task<IActionResult> Get(string fileName)
{
	var imgBytes = await _fileManagerLogic.Get(fileName);
	return File(imgBytes, "image/webp");
}
  • Here we output the bytes array of image data from the 'File' object.
Now let's test our endpoint by adding our image name as a query parameter value.

Endpoint Download File:

For image download, we can use the logic that was implemented for fetching the image. So here we can simply consume the method 'Get(string fileName)' from the 'FileManagerLogic.cs'.
Controllers/ImageController.cs:
[Route("download")]
[HttpGet]
public async Task<IActionResult> Download(string fileName)
{
	var imagBytes = await _fileManagerLogic.Get(fileName);
	return new FileContentResult(imagBytes, "application/octet-stream"){
		FileDownloadName = Guid.NewGuid().ToString()+".webp",
	};
}
  • (Line: 5) Getting image as byte array format.
  • Retruning 'FileContentResult' object by inputing our image byte array data. The content type "application/octet-stream" instructs the browser to download the file. Here we specifying the name of the image after downloading.
So that all about the file managing approaches of Azure Blob Storage from .Net5 Web API.

Video Session:

Support Me!
Buy Me A Coffee PayPal Me

Wrapping Up:

Hopefully, I think this article delivered some useful information of approaches to consume Azure Blob Storage in .Net5 Web API. I love to have your feedback, suggestions, and better techniques in the comment section below.

Refer:

Follow Me:

Comments

  1. It is a really good blog and saved my lot of time. I liked the way it is explain all steps in detail.

    ReplyDelete
  2. really amazing blog thanks for your time to wrote this blog

    ReplyDelete

Post a Comment

Popular posts from this blog

Angular 14 Reactive Forms Example

In this article, we will explore the Angular(14) reactive forms with an example. Reactive Forms: Angular reactive forms support model-driven techniques to handle the form's input values. The reactive forms state is immutable, any form filed change creates a new state for the form. Reactive forms are built around observable streams, where form inputs and values are provided as streams of input values, which can be accessed synchronously. Some key notations that involve in reactive forms are like: FormControl - each input element in the form is 'FormControl'. The 'FormControl' tracks the value and validation status of form fields. FormGroup - Track the value and validate the state of the group of 'FormControl'. FormBuilder - Angular service which can be used to create the 'FormGroup' or FormControl instance quickly. Form Array - That can hold infinite form control, this helps to create dynamic forms. Create An Angular(14) Application: Let'

.NET 7 Web API CRUD Using Entity Framework Core

In this article, we are going to implement a sample .NET 7 Web API CRUD using the Entity Framework Core. Web API: Web API is a framework for building HTTP services that can be accessed from any client like browser, mobile devices, and desktop apps. In simple terminology API(Application Programming Interface) means an interface module that contains programming functions that can be requested via HTTP calls either to fetch or update data for their respective clients. Some of the Key Characteristics of API: Supports HTTP verbs like 'GET', 'POST', 'PUT', 'DELETE', etc. Supports default responses like 'XML' and 'JSON'. Also can define custom responses. Supports self-hosting or individual hosting, so that all different kinds of apps can consume it. Authentication and Authorization are easy to implement. The ideal platform to build the REST full services. Install The SQL Server And SQL Management Studio: Let's install the SQL server on our l

ReactJS(v18) JWT Authentication Using HTTP Only Cookie

In this article, we will implement the ReactJS application authentication using the HTTP-only cookie. HTTP Only Cookie: In a SPA(Single Page Application) Authentication JWT token either can be stored in browser 'LocalStorage' or in 'Cookie'. Storing the JWT token inside of the cookie then the cookie should be HTTP Only. The HTTP-ONly cookie nature is that it will be only accessible by the server application. Client apps like javascript-based apps can't access the HTTP-Only cookie. So if we use the authentication with HTTP-only JWT cookie then we no need to implement the custom logic like adding authorization header or storing token data, etc at our client application. Because once the user authenticated cookie will be automatically sent to the server by the browser on every API call. Authentication API: To authenticate our client application with JWT HTTP-only cookie, I developed a NetJS(which is a node) Mock API. Check the GitHub link and read the document on G

.NET6 Web API CRUD Operation With Entity Framework Core

In this article, we are going to do a small demo on AspNetCore 6 Web API CRUD operations. What Is Web API: Web API is a framework for building HTTP services that can be accessed from any client like browser, mobile devices, desktop apps. In simple terminology API(Application Programming Interface) means an interface module that contains a programming function that can be requested via HTTP calls to save or fetch the data for their respective clients. Some of the key characteristics of API: Supports HTTP verbs like 'GET', 'POST', 'PUT', 'DELETE', etc. Supports default responses like 'XML' and 'JSON'. Also can define custom responses. Supports self-hosting or individual hosting, so that all different kinds of apps can consume it. Authentication and Authorization are easy to implement. The ideal platform to build REST full services. Create A .NET6 Web API Application: Let's create a .Net6 Web API sample application to accomplish our

Angular 14 State Management CRUD Example With NgRx(14)

In this article, we are going to implement the Angular(14) state management CRUD example with NgRx(14) NgRx Store For State Management: In an angular application to share consistent data between multiple components, we use NgRx state management. Using NgRx state helps to avoid unwanted API calls, easy to maintain consistent data, etc. The main building blocks for the NgRx store are: Actions - NgRx actions represents event to trigger the reducers to save the data into the stores. Reducer - Reducer's pure function, which is used to create a new state on data change. Store - The store is the model or entity that holds the data. Selector - Selector to fetch the slices of data from the store to angular components. Effects - Effects deals with external network calls like API. The effect gets executed based the action performed Ngrx State Management flow: The angular component needs data for binding.  So angular component calls an action that is responsible for invoking the API call.  Aft

Unit Testing Asp.NetCore Web API Using xUnit[.NET6]

In this article, we are going to write test cases to an Asp.NetCore Web API(.NET6) application using the xUnit. xUnit For .NET: The xUnit for .Net is a free, open-source, community-focused unit testing tool for .NET applications. By default .Net also provides a xUnit project template to implement test cases. Unit test cases build upon the 'AAA' formula that means 'Arrange', 'Act' and 'Assert' Arrange - Declaring variables, objects, instantiating mocks, etc. Act - Calling or invoking the method that needs to be tested. Assert - The assert ensures that code behaves as expected means yielding expected output. Create An API And Unit Test Projects: Let's create a .Net6 Web API and xUnit sample applications to accomplish our demo. We can use either Visual Studio 2022 or Visual Studio Code(using .NET CLI commands) to create any.Net6 application. For this demo, I'm using the 'Visual Studio Code'(using the .NET CLI command) editor. Create a fo

Angular 14 Crud Example

In this article, we will implement CRUD operation in the Angular 14 application. Angular: Angular is a framework that can be used to build a single-page application. Angular applications are built with components that make our code simple and clean. Angular components compose of 3 files like TypeScript File(*.ts), Html File(*.html), CSS File(*.cs) Components typescript file and HTML file support 2-way binding which means data flow is bi-directional Component typescript file listens for all HTML events from the HTML file. Create Angular(14) Application: Let's create an Angular(14) application to begin our sample. Make sure to install the Angular CLI tool into our local machine because it provides easy CLI commands to play with the angular application. Command To Install Angular CLI npm install -g @angular/cli Run the below command to create the angular application. Command To Create Angular Application ng new name_of_your_app Note: While creating the app, you will see a noti

Part-1 Angular JWT Authentication Using HTTP Only Cookie[Angular V13]

In this article, we are going to implement a sample angular application authentication using HTTP only cookie that contains a JWT token. HTTP Only JWT Cookie: In a SPA(Single Page Application) Authentication JWT token either can be stored in browser 'LocalStorage' or in 'Cookie'. Storing JWT token inside of the cookie then the cookie should be HTTP Only. The HTTP-Only cookie nature is that it will be only accessible by the server application. Client apps like javascript-based apps can't access the HTTP-Only cookie. So if we use authentication with HTTP only JWT cookie then we no need to implement custom logic like adding authorization header or storing token data, etc at our client application. Because once the user authenticated cookie will be automatically sent to the server by the browser on every API call. Authentication API: To implement JWT cookie authentication we need to set up an API. For that, I had created a mock authentication API(Using the NestJS Se

ReactJS(v18) Authentication With JWT AccessToken And Refresh Token

In this article, we are going to do ReactJS(v18) application authentication using the JWT Access Token and Refresh Token. JSON Web Token(JWT): JSON Web Token is a digitally signed and secured token for user validation. The JWT is constructed with 3 important parts: Header Payload Signature Create ReactJS Application: Let's create a ReactJS application to accomplish our demo. npx create-react-app name-of-your-app Configure React Bootstrap Library: Let's install the React Bootstrap library npm install react-bootstrap bootstrap Now add the bootstrap CSS reference in 'index.js'. src/index.js: import 'bootstrap/dist/css/bootstrap.min.css' Create A React Component 'Layout': Let's add a React component like 'Layout' in 'components/shared' folders(new folders). src/components/shared/Layout.js: import Navbar from "react-bootstrap/Navbar"; import { Container } from "react-bootstrap"; import Nav from "react-boot

A Small Guide On NestJS Queues

NestJS Application Queues helps to deal with application scaling and performance challenges. When To Use Queues?: API request that mostly involves in time taking operations like CPU bound operation, doing them synchronously which will result in thread blocking. So to avoid these issues, it is an appropriate way to make the CPU-bound operation separate background job.  In nestjs one of the best solutions for these kinds of tasks is to implement the Queues. For queueing mechanism in the nestjs application most recommended library is '@nestjs/bull'(Bull is nodejs queue library). The 'Bull' depends on Redis cache for data storage like a job. So in this queueing technique, we will create services like 'Producer' and 'Consumer'. The 'Producer' is used to push our jobs into the Redis stores. The consumer will read those jobs(eg: CPU Bound Operations) and process them. So by using this queues technique user requests processed very fastly because actually