Katalyst.App.Storage 1.2.1

App.Storage

Vendor-agnostic object storage for .NET: upload, open, delete, and existence checks via IFileStorage, with built-in Amazon S3 and Azure Blob Storage providers. Streams are used end-to-end (from a web app, pass IFormFile.OpenReadStream() when uploading).

This project is not referenced by the rest of the WebTemplate by default; add a PackageReference to Katalyst.App.Storage or a ProjectReference when you adopt it.

Packages

• AWSSDK.S3 — S3 API; credentials follow the AWS SDK default chain.
• Azure.Storage.Blobs — Blob service.
• Microsoft.Extensions.* — options and DI.

Registration

Use AddAppStorage and pick one of UseAmazonS3, UseAzureBlob, or UseCustom. The configuration section names below match AppStorageOptions.SectionName ("Storage") plus a provider key.

using App.Storage.DependencyInjection;

builder.Services.AddAppStorage(builder.Configuration, storage =>
{
    storage.UseAmazonS3(builder.Configuration.GetSection("Storage:AmazonS3"));
    // or: storage.UseAzureBlob(builder.Configuration.GetSection("Storage:AzureBlob"));
});

Inject IFileStorage where you need to read or write objects.

Example appsettings.json (Amazon S3)

{
  "Storage": {
    "AmazonS3": {
      "BucketName": "my-app-uploads",
      "Prefix": "uploads",
      "Region": "us-east-1"
    }
  }
}

Region is optional (defaults to us-east-1). Prefix is optional and prepended to every object key.

Example appsettings.json (Azure Blob)

{
  "Storage": {
    "AzureBlob": {
      "ConnectionString": "UseDevelopmentStorage=true;",
      "ContainerName": "uploads",
      "Prefix": "files"
    }
  }
}

Ensure the container exists (or create it out of band); the library does not create the container automatically.

Usage

using App.Storage.Contracts;

public class MyService(IFileStorage files)
{
    public async Task SaveAsync(string key, Stream content, CancellationToken ct)
    {
        await files.UploadAsync(key, content, contentType: "application/pdf", ct);
    }

    public async Task<Stream> LoadAsync(string key, CancellationToken ct)
    {
        return await files.OpenReadAsync(key, ct); // dispose the stream when done
    }

    public Task DeleteAsync(string key, CancellationToken ct) => files.DeleteAsync(key, ct);

    public Task<bool> ExistsAsync(string key, CancellationToken ct) => files.ExistsAsync(key, ct);
}

Custom provider

Implement IFileStorage and register:

services.AddAppStorage(configuration, storage => storage.UseCustom<MyFileStorage>());