Katalyst.Core.FileStorage 1.0.0

Core.FileStorage

Small abstraction over blob/object storage with dependency injection: local filesystem, Amazon S3, or Azure Blob Storage. The active backend is chosen from configuration (Storage:Provider).

Installation

Reference this project (or package) from your application and ensure configuration is available (IConfiguration). For S3, configure AWS credentials using the AWS SDK default credential chain. For Azure, supply a storage connection string.

Transitive packages include AWSSDK.S3 and Azure.Storage.Blobs; unused providers still ship with those dependencies today.

Configuration (appsettings.json)

All providers share a root section Storage. Set Storage:Provider to one of:

Names are compared case-insensitively.

Example: Local filesystem

{
  "Storage": {
    "Provider": "Local",
    "Local": {
      "RootPath": "C:\\app-data\\blobs",
      "Prefix": ""
    }
  }
}

For paths that must not follow this heuristic (for example ASP.NET content root instead of the project folder), set RootPath to an absolute path you compute at startup (e.g. Path.Combine(builder.Environment.ContentRootPath, "App_Data", "files")).

Example: Amazon S3

{
  "Storage": {
    "Provider": "S3",
    "AmazonS3": {
      "BucketName": "my-app-bucket",
      "Region": "us-east-1",
      "Prefix": "uploads"
    }
  }
}

Example: Azure Blob Storage

{
  "Storage": {
    "Provider": "Azure",
    "AzureBlob": {
      "ConnectionString": "DefaultEndpointsProtocol=https;AccountName=...;AccountKey=...;EndpointSuffix=core.windows.net",
      "ContainerName": "my-container",
      "Prefix": "uploads"
    }
  }
}

You can keep all three subsections in one file and switch Provider between environments.

Registering services

ASP.NET Core minimal hosting

using Core.FileStorage.DependencyInjection;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddAppStorage(builder.Configuration);

var app = builder.Build();

Resolve Core.FileStorage.Contracts.IFileStorage from DI (constructors or minimal APIs).

Console app or generic host (ServiceCollection)

using Core.FileStorage.Contracts;
using Core.FileStorage.DependencyInjection;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

var configuration = new ConfigurationBuilder()
    .SetBasePath(AppContext.BaseDirectory)
    .AddJsonFile("appsettings.json", optional: false)
    .Build();

var services = new ServiceCollection();
services.AddSingleton<IConfiguration>(configuration);
services.AddAppStorage(configuration);

await using ServiceProvider provider = services.BuildServiceProvider();
var storage = provider.GetRequiredService<IFileStorage>();

Using IFileStorage

using Core.FileStorage.Contracts;

// Upload
await using var upload = new MemoryStream(System.Text.Encoding.UTF8.GetBytes("Hello"));
await storage.UploadAsync("documents/hello.txt", upload, contentType: "text/plain", cancellationToken);

// Exists
var exists = await storage.ExistsAsync("documents/hello.txt", cancellationToken);

// Download (dispose the stream when finished)
await using var readStream = await storage.OpenReadAsync("documents/hello.txt", cancellationToken);

// Delete
await storage.DeleteAsync("documents/hello.txt", cancellationToken);

Custom implementation

Register your own type instead of calling AddAppStorage:

services.AddSingleton<IFileStorage, MyCustomFileStorage>();

Constants

Section and provider key names are defined on Core.FileStorage.AppStorageOptions (SectionName = "Storage", ProviderKey = "Provider").