Upload File Into Azure Blob Storage And Trigger Blob Storage Using Azure Function

Step 8

Add blob storage connection string and container name inside the app settings file.

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*",
  "ConnectionStrings": {
    "AzureBlobStorageKey": ""
  },
  "BlobContainer": "jdlearningblobcontainer"
}

Step 9

Register a few services inside the Program class

using Azure.Storage.Blobs;
using AzureBlobStorageDemo.Repositories;
using Microsoft.Extensions.Configuration;
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddScoped(_ => {
    return new BlobServiceClient(builder.Configuration.GetConnectionString("AzureBlobStorageKey"));
});
builder.Services.AddScoped < IBlobStorage, BlobStorage > ();
builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
var app = builder.Build();
// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment()) {
    app.UseSwagger();
    app.UseSwaggerUI();
}
app.UseHttpsRedirection();
app.UseAuthorization();
app.MapControllers();
app.Run();

Step 10

Create a new files controller

using AzureBlobStorageDemo.Models;
using AzureBlobStorageDemo.Repositories;
using Microsoft.AspNetCore.Mvc;
namespace AzureBlobStorageDemo.Controllers {
    [Route("api/[controller]")]
    [ApiController]
    public class FilesController: ControllerBase {
        private readonly IBlobStorage _blobService;
        public FilesController(IBlobStorage blobService) {
            _blobService = blobService;
        }
        /// <summary>
        /// upload file
        /// </summary>
        /// <param name="fileDetail"></param>
        /// <returns></returns>
        [HttpPost("Upload")]
        public async Task < IActionResult > UploadFile([FromForm] FileDetails fileDetail) {
            if (fileDetail.file != null) {
                await _blobService.UploadFileAsync(fileDetail);
            }
            return Ok();
        }
    }
}

Step 11

Run your project

Azure Blob Trigger Function

Step 1

Open visual studio and create a new azure function

Step 2

Configure your new function

Step 3

Provide some additional information like connection string setting name and container name.

Step 4

We need the following NuGet Packages.

Step 5

Create a new Blob Details class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace AzureBlobTriggerFunction {
    public class BlobDetails {
        public Guid Id {
            get;
            set;
        }
        public string FileName {
            get;
            set;
        }
        public bool isFileUploaded {
            get;
            set;
        }
        public DateTime DateOfUpdation {
            get;
            set;
        }
    }
}

Step 6

Add blob storage connection string inside the local setting JSON file

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet",
    "AzureBlobStorageKey": ""
  }
}

Step 7

Finally, add the following code inside the function which triggers blob storage and saves the uploaded file data inside the SQL Server Database. Here I added SQL Code, but in real-time if you want to process your data and need to send it anywhere, you can add code as per your requirement.

using System;
using System.Data.SqlClient;
using System.IO;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Host;
using Microsoft.Extensions.Logging;
namespace AzureBlobTriggerFunction {
    public class BlobTrigger {
        [FunctionName("BlobTrigger")]
        public void Run([BlobTrigger("jdlearningblobcontainer/{name}", Connection = "AzureBlobStorageKey")] Stream myBlob, string name, ILogger log) {
            log.LogInformation($ "C# Blob trigger function Processed blob\n Name:{name} \n Size: {myBlob.Length} Bytes");
            using(SqlConnection conn = new SqlConnection("Data Source=DESKTOP-8RL8JOG;Initial Catalog=AzureDemo;User Id=sa;Password=database@1;")) {
                conn.Open();
                var insertQuery = $ "INSERT INTO [BlobDetails] (FileName,isFileUploaded,DateOfUpdation) VALUES('{name}', '{true}' , '{DateTime.UtcNow}')";
                using(SqlCommand cmd = new SqlCommand(insertQuery, conn)) {
                    var rows = cmd.ExecuteNonQuery();
                    log.LogInformation($ "{rows} rows were updated");
                }
            }
        }
    }
}

Step 8

Now, run your function application.

You can see in the above image our function is in the running add listen to blob storage.

Step 9

Upload a file using the Web API application

After the file is uploaded on Azure, our function triggers blob storage, receives the file details, and stores them inside the SQL Server Database Table.

(Note: This is just for an example purpose. If you want to process your data and perform some operations, then add that code as per your requirement.

Conclusion

Here we discuss the azure storage account and blob trigger functions. Also, the step-by-step implementation using .NET Core.

Happy Learning!