How to get a list of all the blobs in a container

Question

I have the account name and account key of a storage account in Azure. I need to get a list of all the blobs in a container in that account. (The "$logs" container).

I am able to get the information of a specific blob using the CloudBlobClient class but can't figure out how to get a list of all the blobs within the $logs container.

Answer 1

Here's the updated API call for WindowsAzure.Storage v9.0:

private static CloudBlobClient _blobClient = CloudStorageAccount.Parse("connectionstring").CreateCloudBlobClient();

public async Task<IEnumerable<CloudAppendBlob>> GetBlobs()
{
    var container = _blobClient.GetContainerReference("$logs");
    BlobContinuationToken continuationToken = null;

    //Use maxResultsPerQuery to limit the number of results per query as desired. `null` will have the query return the entire contents of the blob container
    int? maxResultsPerQuery = null;

    do
    {
        var response = await container.ListBlobsSegmentedAsync(string.Empty, true, BlobListingDetails.None, maxResultsPerQuery, continuationToken, null, null);
        continuationToken = response.ContinuationToken;
        foreach (var blob in response.Results.OfType<CloudAppendBlob>())
        {
            yield return blob;
        }
    } while (continuationToken != null);
}

Answer 2

There is a sample of how to list all of the blobs in a container at https://azure.microsoft.com/en-us/documentation/articles/storage-dotnet-how-to-use-blobs/#list-the-blobs-in-a-container:

// Retrieve storage account from connection string.
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
CloudConfigurationManager.GetSetting("StorageConnectionString"));

// Create the blob client.
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

// Retrieve reference to a previously created container.
CloudBlobContainer container = blobClient.GetContainerReference("photos");

// Loop over items within the container and output the length and URI.
foreach (IListBlobItem item in container.ListBlobs(null, false))
{
    if (item.GetType() == typeof(CloudBlockBlob))
    {
        CloudBlockBlob blob = (CloudBlockBlob)item;
        Console.WriteLine("Block blob of length {0}: {1}", blob.Properties.Length, blob.Uri);
    }
    else if (item.GetType() == typeof(CloudPageBlob))
    {
        CloudPageBlob pageBlob = (CloudPageBlob)item;
        Console.WriteLine("Page blob of length {0}: {1}", pageBlob.Properties.Length, pageBlob.Uri);
    }
    else if (item.GetType() == typeof(CloudBlobDirectory))
    {
        CloudBlobDirectory directory = (CloudBlobDirectory)item;
        Console.WriteLine("Directory: {0}", directory.Uri);
    }
}

Answer 3

Use ListBlobsSegmentedAsync which returns a segment of the total result set and a continuation token.

ref:https://docs.microsoft.com/en-us/azure/storage/blobs/storage-quickstart-blobs-dotnet?tabs=windows

Answer 4

Since you container name is $logs, so i think your blob type is append blob. Here's a method to get all blobs and return IEnumerable:

    private static CloudBlobClient _blobClient = CloudStorageAccount.Parse("connectionstring").CreateCloudBlobClient();
    public IEnumerable<CloudAppendBlob> GetBlobs()
    {
        var container = _blobClient.GetContainerReference("$logs");
        BlobContinuationToken continuationToken = null;

        do
        {
            var response = container.ListBlobsSegmented(string.Empty, true, BlobListingDetails.None, new int?(), continuationToken, null, null);
            continuationToken = response.ContinuationToken;
            foreach (var blob in response.Results.OfType<CloudAppendBlob>())
            {
                yield return blob;
            }
        } while (continuationToken != null);
    }

The method can be asynchronous, just use ListBlobsSegmentedAsync. One thing you need to note is the argument useFlatBlobListing need to be true which means that ListBlobs will return a flat list of files as opposed to a hierarchical list.