Copying file across Azure container without using azcopy

Question

I would like to Copy a file across Azure containers without using azcopy utility. Please help with the script(Spring boot or .net example).

I was able to upload\download file from\to local from\to container. Now wondering, how I could achieve remote to remote copy.

Following code is working fine. All I need now is remote copy.

using Azure.Storage.Blobs;
using Azure.Storage.Blobs.Models;
using Microsoft.Azure.Storage.Blob;
using System;
using System.IO;
using System.Threading.Tasks;

namespace whizlabblob
{
    class Program
    {
        static string storageconnstring = "DefaultEndpointsProtocol=https;AccountName=mainices;AccountKey=********************";
        static string containerName = "demo";
        static string filename = "sample.txt";
        static string filepath="C:\\Work\\sample.txt";
        static string downloadpath = "C:\\Work\\sample2.txt";
        static async Task Main(string[] args)
        {
            //Container().Wait();
            //CreateBlob().Wait();
            //GetBlobs().Wait();
            // GetBlob().Wait();
            Console.WriteLine("Complete");
            Console.ReadKey();
        }

        static async Task Container()
        {
         
            BlobServiceClient blobServiceClient = new BlobServiceClient(storageconnstring);
         
            BlobContainerClient containerClient = await blobServiceClient.CreateBlobContainerAsync(containerName);
        }



        static async Task CreateBlob()
        {
            
            BlobServiceClient blobServiceClient = new BlobServiceClient(storageconnstring);
            
            BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName);
            
            BlobClient blobClient = containerClient.GetBlobClient(filename);            
            using FileStream uploadFileStream = File.OpenRead(filepath);
            

            await blobClient.UploadAsync(uploadFileStream, true);
            uploadFileStream.Close();
        }


        static async Task GetBlobs()
        {
            
            BlobServiceClient blobServiceClient = new BlobServiceClient(storageconnstring);
            
            BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName);
            
            
            await foreach (BlobItem blobItem in containerClient.GetBlobsAsync())
            {
                Console.WriteLine("\t" + blobItem.Name);
            }

        }

        static async Task GetBlob()
        {
            
            BlobServiceClient blobServiceClient = new BlobServiceClient(storageconnstring);
            
            BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName);
            
            BlobClient blob = containerClient.GetBlobClient(filename);
            
            BlobDownloadInfo blobdata = await blob.DownloadAsync();

            
            using (FileStream downloadFileStream = File.OpenWrite(downloadpath))
            {
                await blobdata.Content.CopyToAsync(downloadFileStream);
                downloadFileStream.Close();
            }


            // Read the new file
            using (FileStream downloadFileStream = File.OpenRead(downloadpath))
            {
                using var strreader = new StreamReader(downloadFileStream);
                string line;
                while ((line = strreader.ReadLine()) != null)
                {
                    Console.WriteLine(line);
                }
            }

        }
    }
}

Answer 1

You were almost there :). In order to copy a blob from one container to another, you just need to create an instance of BlobClient for a blob in the target container and call StartCopyFromUriAsync method and pass the URI of the source blob.

Here's the code to do that:

    static async Task CopyBlob()
    {
        BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString);

        BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName);

        BlobClient blobClient = containerClient.GetBlobClient(filename);
        var blobUri = blobClient.Uri;

        BlobContainerClient targetContainerClient = blobServiceClient.GetBlobContainerClient("demo-copy");//This is the container where we want to copy the blob
        BlobClient targetBlobClient = targetContainerClient.GetBlobClient(filename);
        await targetBlobClient.StartCopyFromUriAsync(blobUri);
    }

A few things to keep in mind:

• Because you're copying blob in the same storage account, you just need the source blob's URI. However if you're copying blobs across storage account, you will need to ensure that the URI you provide to copy method should be publicly accessible.
• Again because you're copying blob in the same storage account, the server-side copy operation is synchronous. If you're copying blob across storage account, the operation is asynchronous and may take some time to finish. You must wait for the copy operation to finish before taking any action on the source blob (like deleting it).