Skip to main content

NestJS API File Operations Using Azure Blob Storage

In this article, we are going to use Azure Blob Storage for all file operations like uploading, downloading, and deleting files from the NestJS API endpoint.

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 ''.

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.

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 NestJS Application:

Now our goal is to create NestJs endpoints for operating files in Azure Blob Storage. So let's create a NestJS application.
Command To Install CLI:
npm i -g @nestjs/cli
Command To Create NestJS App:
nest new your_project_name

Install Azure Blob Storage NodJS Package:

npm install @azure/storage-blob

Install NodeJS Multer Package:

In NestJS for handling file upload operation, it is the best choice to install the 'Multer' package. It is very effective in reading 'multipart/formdata'. The'Multer' also provides more type safety.
Multer Package:
npm i -D @types/multer

Azure Connectionstring:

There different ways like Authentication, ConnectionString, SharedSASToken, etc to communicate with the Azure Blob Storage.

In this demo, I'm going to use the ConnectionString in NestJS API to interact with the Azure Blob Storage. In Azure Storage Account, the left-hand side under settings select 'Access Keys' menu and it will display 'Key1' and 'Key2' access keys. We can choose any one of them.

NestJS Endpoint For Uploading File To Azure Blob Storage:

We have to implement our logic to create a file upload endpoint in NestJS.
import { BlobServiceClient, BlockBlobClient } from '@azure/storage-blob';
import { Injectable } from '@nestjs/common';

export class AppService {
  azureConnection = "DefaultEndpointsProtocol=https;AccountName=naveenazurestore;AccountKey=NLNxbk2ElnaMaUucTLt1zQDU1eOznjYUmCaiIeJB6O+934iedXSmss+r5gDePmZE6y99X8zZ8AItA==;";
  containerName = "upload-file";

    const blobClientService = BlobServiceClient.fromConnectionString(this.azureConnection);
    const containerClient = blobClientService.getContainerClient(this.containerName);
    const blobClient = containerClient.getBlockBlobClient(imageName);
    return blobClient;

  async upload(file:Express.Multer.File){
    const blobClient = this.getBlobClient(file.originalname);
    await blobClient.uploadData(file.buffer);
  • (Line: 1) Instances like 'BlobServiceClient' & 'BlockBlobClient' loading from '@azure/storage-blob'.
  • (Line: 7) Azure connection string.
  • (Line: 8) Azure Blob Storage container name. This our target container to upload our files from our NestJS API endpoint.
  • (Line: 11-16) The 'getBlobClient' method returns 'BlockBlobClient' from our specified 'Blob'(here Blob means our file to upload).
  • (Line: 12)  Configuring our azure connection string into the 'BlobServiceClient'.
  • (Line: 13)  Configuring our container name.
  • (Line: 14)  Configuring the name of our file to be upload and returning the 'BlockBlobClient' instance. The 'BlockBlobClient' now contains all the configurations like connection, container, filename.
  • (Line: 18-21) The 'upload' method contains logic to upload files to Azure Blob Storage. Its input parameter is a file of type 'Multer.File'.
  • (Line: 19) Fetching 'BlockBlobClient' instance.
  • (Line: 20) Invoking file upload call by using 'uploadData' method from the 'BlockBlobClient' instance. The 'uploadData' takes file buffer as input.
import { Controller, Post, UploadedFile, UseInterceptors } from '@nestjs/common';
import { FileInterceptor } from '@nestjs/platform-express';
import { AppService } from './app.service';

export class AppController {
  constructor(private readonly appService: AppService) {}

  async upload(@UploadedFile() file: Express.Multer.File):Promise<string>{
    await this.appService.upload(file);
    return "uploaded";
  • (Line: 11) The 'FileInterceptor' reads all file stream from the 'myfile'(name attribute value or form data value).
  • (Line: 12) The '@UploadedFile()' decorator grabs the all file information and assigns it to the variable like 'file' in our sample. Here we are defining the type as 'Express.Multer.File'.
  • (Line: 13) Passing file to the 'upload' method.
Now let's test our endpoint from the 'Postman' tool(Note: While uploading from Postman tool, clear all headers).
Now check in the Azure dashboard.

Create NestJS Endpoint To Read File:

The new endpoint going to fetch the steam of file from the Azure Blob Storage and then render it on the browser.
async getfileStream(fileName: string){
  const blobClient = this.getBlobClient(fileName);
  var blobDownloaded = await;
  return blobDownloaded.readableStreamBody;
  • Fetching required image or file stream from Azure Blob Storage by using the 'download()' method of 'BlockBlobClien' instance.
import { Controller, Get, Header, Post, Query, Res, UploadedFile, UseInterceptors } from '@nestjs/common';
import { FileInterceptor } from '@nestjs/platform-express';
import { AppService } from './app.service';
// some code hidden for display purpose
export class AppController {
  constructor(private readonly appService: AppService) {}

  async readImage(@Res() res,@Query('filename') filename){
    const file = await this.appService.getfileStream(filename);
    return file.pipe(res);
  • (Line: 11) '@Header()' decorator used to specify the 'Content-Type' and its value 'image/webp'(webp is image format like jpg, png, webp, etc). Because of this header value, the image stream going to be rendered on the browser.
  • (Line: 12) '@Res()' decorator is response object. '@Query()' decorator to capture query params.
  • (Line: 13-14) After getting the file stream from Azure Blob Storage, we are flushing the stream into the response object.
Now try to access this new endpoint and check the result.

Create NestJS Endpoint To Download Image:

The new endpoint on opening it on a browser it's going to download the image from the Azure blob storage.

So logic to download image same as the read image endpoint just we created above, the only difference we need to add a one addition header decorator here.
@Header('Content-Disposition', 'attachment; filename=test.webp')
async downloadImage(@Res() res,@Query('filename') filename){
    const file = await this.appService.getfileStream(filename);
    return file.pipe(res);
(Line: 3) This header 'Content-Disposition' and its value 'attachment' makes the browser understand that response should be downloaded.

Create NestJS Endpoint To Delete Image:

The new endpoint going to delete the files from the Azure blob storage.
async delete(filename: string){
 const blobClient = this.getBlobClient(filename);
 await blobClient.deleteIfExists();
  • The 'deleteIfExists' method going to delete the file if exists on the Azure blob storage.
async delete(@Query('filename') filename){
 await this.appService.delete(filename);
 return "deleted";
That's all about file operation in Azure Blob Storage from the NestJS application.

Video Session:

Support Me!
Buy Me A Coffee PayPal Me

Wrapping Up:

Hopefully, I think this article delivered some useful information about NestJS API file operations using Azure Blob Storage. I love to have your feedback, suggestions, and better techniques in the comment section below.


Follow Me:


  1. Nice tutorial. I was looking for a file upload example using NestJS and possibly Multer... This video gave me some good hints...


Post a Comment

Popular posts from this blog

Blazor WebAssembly Custom Authentication From Scratch

In this article, we are going to explore and implement custom authentication from the scratch. In this sample, we will use JWT authentication for user authentication. Main Building Blocks Of Blazor WebAssembly Authentication: The core concepts of blazor webassembly authentication are: AuthenticationStateProvider Service AuthorizeView Component Task<AuthenticationState> Cascading Property CascadingAuthenticationState Component AuthorizeRouteView Component AuthenticationStateProvider Service - this provider holds the authentication information about the login user. The 'GetAuthenticationStateAsync()' method in the Authentication state provider returns user AuthenticationState. The 'NotifyAuthenticationStateChaged()' to notify the latest user information within the components which using this AuthenticationStateProvider. AuthorizeView Component - displays different content depending on the user authorization state. This component uses the AuthenticationStateProvider

How Response Caching Works In Asp.Net Core

What Is Response Caching?: Response Caching means storing of response output and using stored response until it's under it's the expiration time. Response Caching approach cuts down some requests to the server and also reduces some workload on the server. Response Caching Headers: Response Caching carried out by the few Http based headers information between client and server. Main Response Caching Headers are like below Cache-Control Pragma Vary Cache-Control Header: Cache-Control header is the main header type for the response caching. Cache-Control will be decorated with the following directives. public - this directive indicates any cache may store the response. private - this directive allows to store response with respect to a single user and can't be stored with shared cache stores. max-age - this directive represents a time to hold a response in the cache. no-cache - this directive represents no storing of response and always fetch the fr

Endpoint Routing In Asp.Net Core

How Routing Works In  Core 2.1 And Below Versions?: In Asp.Net Core routing is configured using app.UseRouter() or app.UseMvc() middleware. app.UseMvc(routes => { routes.MapRoute( name: "default", template: "{controller=Home}/{action=Index}/{id?}"); }); Here in Dotnet Core version 2.1 or below versions on the execution of route middleware request will be navigated appropriate controller matched to the route. An operation or functionality which is dependent on route URL or route values and that need to be implemented before the execution of route middleware can be done by accessing the route path from the current request context as below app.Use(async (context, next) => { if(context.Request.Path.Value.IndexOf("oldvehicle") != -1) { context.Response.Redirect("vehicle"); } else { await next(); } }); app.UseMvc(routes => { routes.MapRoute( name: "vehicleRoute", template: "vehicle", defaul

Asp.Net Core MVC Form Validation Techniques

Introduction: Form validations in any applications are like assures that a valid data is storing on servers. All programing frameworks have their own individual implementations for form validations. In Dotnet Core MVC application server-side validations carried on by the models with the help of Data Annotations and the client-side validations carried by the plugin jQuery Unobtrusive Validation. jQuery Unobtrusive Validation is a custom library developed by Microsoft based on the popular library  jQuery Validate . In this article, we are going to learn how the model validation and client-side validation works in Asp.Net Core MVC Application with sample examples. Getting Started: Let's create an Asp.Net Core MVC application project using preferred editors like Microsoft Visual Studio or Microsoft Visual Studio Code. Here I'm using Visual Studio. Let's create an MVC controller and name it as 'PersonController.cs' and add an action method as bel

.NET Core MVC Application File Upload To Physical Location With Buffered Technique

Buffering Technique In File Upload: The server will use its Memory(RAM) or Disk Storage to save the files on receiving a file upload request from the client.  Usage of Memory(RAM) or Disk depends on the number of file requests and the size of the file.  Any single buffered file exceeding 64KB is moved from Memory to a temp file on disk.  If an application receives heavy traffic of uploading files there might be a chance of out of Disk or RAM memory which leads to crash application. So this Buffer technique used for small files uploading. In the following article, we create a sample for the file uploading using .NET Core MVC application. Create The .NET Core MVC Project: Let's create a .NET Core MVC project, here for this sample I'm using Visual Studio Code as below.   Check the link to use the Visual Studio Code for .NET Core Application . IFormFile: Microsoft.AspNetCore.Http.IFormFile used for file upload with buffered technique. On uploading files f

Ionic Picker Sample Code In Angular

Introduction: Ionic Picker(ion-picker) is a popup slides up from the bottom of the device screen, which contains rows with selectable column separated items. The main building block of ion-picker as follows: PickerController PickerOptions PickerController: PickerController object helps in creating an ion-picker overlay. create(opts?: Opts): Promise<Overlay> PickerController create method helps in create the picker overlay with the picker options PickerOptions: PickerOptions is a configuration object used by PickerController to display ion-picker. Single Column Ionic Picker: single.item.picker.ts: import { Component } from "@angular/core"; import { PickerController } from "@ionic/angular"; import { PickerOptions } from "@ionic/core"; @Component({ selector: "single-column-picker", templateUrl:"single.item.picker.html" }) export class SingleItemPicker { animals: string[] = ["Tiger&quo

.Net Core HttpClient JSON Extension Methods Using System.Net.Http.Json Package

.Net Core 3.0 onwards Microsoft brought up a new package called System.Net.Http.Json. This new package provides JSON extension methods for HttpClient. These JSON extension methods will have a prebuild mechanism for serializing or deserializing response data or payload of HttpClient call. System.Net.Http.Json extension methods that are provided to HttpClient, few of them are mentioned below. GetFromJsonAsync PostAsJsonAsync PutAsJsonAsync ReadFromJsonAsync In this article, we understand System.Net.Http.Json package by implementing the HttpClient samples by with and without JSON extension methods and compare them. Create A .Net Core Web API Sample Application: Let's create a .Net Core sample Web API application, from this application we will consume another Web API by implementing HttpClient calls. We can create a Web API sample application using IDE like Visual Studio 2019(Supports .Net Core 3.0 plus) or  Visual Studio Code . Create A Typed Client: In .Net Core using the Http

GraphQL API Integration In Asp.Net Core Application

Introduction: GraphQL is a query language for your API and a server-side runtime for executing queries by using a type system you define for your data. GraphQL can be integrated into any framework like ASP.NET, Java, NestJs, etc and it isn't tied to any specific database or storage engine and is instead backed by your existing code and data. How GraphQL API Different From Rest API: GraphQL exposes a single end-point or route for the entire application, regardless of its responses or actions. HTTP-POST is the only Http verb recommended by the GraphQL. The client applications (consumers of API) can give instructions to GraphQL API about what type of properties to be returned in the response. Building Blocks Of GraphQL API: The main building blocks of GraphQL API is Schemas and Types.  A 'Schema' in GrpahQL API describes the functionality available to the clients connect to API. Schema mostly consists of GraphQL Object Types, Queries, Mutations, etc. T

ASP.NET Core Web API Versioning

Introduction: An iteration and evolutionary changes of an ASP.NET Core Web API is handled by Versioning. Versioning of an API gives confidence to the clients which consumes API for a long time. Any changes or development of an API will be accessible using the new version and it won't cause issues to the clients consuming the old version of API. When To Use Versioning: Any API response changes. Developing an API by implementing testing levels like 'Alpha', 'Beta', and 'RC' versions before releasing Production. Deprecating an API which means API going to be removed or upgraded by a version within a short period. Versioning Types: Query String Versioning Url Path Versioning Media Type Versioning API Version Nuget: To Configure versioning to AspNet Core Web API Microsoft provided a library(Microsoft.AspNetCore.Mvc.Versioning). So to use the versioning library please install NuGet below.              Install-Package Microsoft.A

Blazor Server CRUD Operations

Introduction: Blazor Server is a web framework to develop server-side single-page applications. Blazor is made up of components with the combinations on C#, Html, CSS.  Blazor Server is production-ready from the .Net Core 3.0.  Blazor Server Working Mechanism: Blazor Server is a very light-weight web development framework.  In Blazor Server, not all code gets downloaded to the client browsers. Blazor Server made of components these components can be a block of code or page with respective navigation.  Blazor server application communicates with the server with a SignalR background connection which is inbuilt functionality. Application click,  form submission, change events, application page navigation every operation is carried out by the SignalR connection by communicating with the server.  Blazor updates the Html DOM very gently on every data update without any overhead. Blazor Server application maintains a nice intelligent tree structure to update the required inform