SideSoftware.Storage

Azure Blob Storage abstractions and implementation for .NET 10, with configurable file size limits, content type validation, SAS URL generation, and async streaming.

Installation

dotnet add package SideSoftware.Storage

Configuration

Add blob storage settings to your appsettings.json:

{
  "BlobStorage": {
    "ConnectionString": "UseDevelopmentStorage=true",
    "DefaultContainer": "documents",
    "DefaultSasExpirationMinutes": 60,
    "MaxFileSizeBytes": 10485760,
    "AllowedContentTypes": [
      "image/jpeg",
      "image/png"
    ]
  }
}

Register services in your DI container:

builder.Services.Configure<BlobStorageSettings>(
    builder.Configuration.GetSection(BlobStorageSettings.SectionName));

builder.Services.AddSingleton<IBlobStorageService, AzureBlobStorageService>();

Usage

Upload a file

var result = await blobStorage.UploadAsync("reports/monthly.pdf", fileStream);
// result.FullPath => "documents/reports/monthly.pdf"

Upload with options

var result = await blobStorage.UploadAsync("photo.jpg", imageBytes, new UploadBlobOptions
{
    ContainerName = "images",
    ContentType = "image/jpeg",
    Overwrite = false,
    Metadata = new Dictionary<string, string> { ["Author"] = "Jane" }
});

Download a file

// Streaming download
var result = await blobStorage.DownloadAsync("reports/monthly.pdf");
await result.Content.CopyToAsync(outputStream);

// Byte array download
byte[] bytes = await blobStorage.DownloadBytesAsync("reports/monthly.pdf");

Generate a SAS URL

var sas = await blobStorage.GetSasUrlAsync("reports/monthly.pdf", new BlobSasOptions
{
    ExpirationMinutes = 30,
    AllowRead = true,
    ContentDisposition = "attachment; filename=\"report.pdf\""
});
// sas.Url => time-limited URL for direct access

List blobs

await foreach (var blob in blobStorage.ListAsync(prefix: "reports/"))
{
    Console.WriteLine($"{blob.BlobName} ({blob.SizeBytes} bytes)");
}

Other operations

bool exists = await blobStorage.ExistsAsync("photo.jpg");
StoredBlobInfo? info = await blobStorage.GetInfoAsync("photo.jpg");
bool deleted = await blobStorage.DeleteAsync("photo.jpg");
await blobStorage.CopyAsync("photo.jpg", "photo-backup.jpg");
await blobStorage.EnsureContainerExistsAsync("my-container");

Credential Document Storage

A higher-level ICredentialDocumentStorage interface is included for managing credential documents (e.g., pilot licenses, medical certificates) with structured blob paths and metadata:

builder.Services.AddSingleton<ICredentialDocumentStorage, CredentialDocumentStorage>();

// Upload
var doc = await credentialStorage.UploadAsync(
    personId, "pilot-license", fileStream, "license.pdf");

// Get a time-limited view URL
string viewUrl = await credentialStorage.GetViewUrlAsync(doc.BlobPath);

// Get a download URL (prompts browser to save)
string downloadUrl = await credentialStorage.GetDownloadUrlAsync(
    doc.BlobPath, "pilot-license.pdf");

// List all documents for a person
await foreach (var item in credentialStorage.ListForPersonAsync(personId))
{
    Console.WriteLine($"{item.OriginalFileName} - {item.ContentType}");
}

License

MIT