FileBlobEmulator

A lightweight Azure Blob Storage emulator that stores blobs directly on the file system. Designed as a faster alternative to Azurite for local development and testing.

Features

• ✅ File-based storage - Blobs stored directly as files, not JSON
• ✅ Azure Blob API compatible - Works with Azure SDK
• ✅ SharedKey authentication - Full HMAC-SHA256 signature validation
• ✅ Block blob support - Single-shot and block upload
• ✅ Container operations - Create, delete, list blobs
• ✅ Swagger UI - API documentation in development mode

Quick Start

Prerequisites

• .NET 9.0 SDK
• Docker (optional)

Environment Variables

Variable	Description	Required
BLOB_ACCOUNT_NAME	Storage account name	✅ Yes
BLOB_ACCOUNT_KEY	Base64-encoded account key	✅ Yes
BLOB_ROOT	Root directory for blob storage	No (default: blob-data)

Run Locally

# Set environment variables
export BLOB_ACCOUNT_NAME=devstoreaccount1
export BLOB_ACCOUNT_KEY=Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw==

# Run the application
cd src/services/FileBlobEmulator
dotnet run

The server will start at https://localhost:5001 (or http://localhost:5000).

Run with Docker (Recommended)

docker run -d \
  -p 5000:8080 \
  -e BLOB_ACCOUNT_NAME=devstoreaccount1 \
  -e BLOB_ACCOUNT_KEY=Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw== \
  -v $(pwd)/blob-data:/app/blob-data \
  tieuanhquoc/fileblobemulator:latest

Build from Source

# Clone and build
docker build -t fileblobemulator .

# Or run with .NET directly
cd src/services/FileBlobEmulator
dotnet run

API Endpoints

Container Operations

Method	Endpoint	Description
PUT	/{account}/{container}?restype=container	Create container
DELETE	/{account}/{container}?restype=container	Delete container
GET	/{account}/{container}?restype=container&comp=list	List blobs

Blob Operations

Method	Endpoint	Description
PUT	/{account}/{container}/{blob}	Upload blob (single-shot)
PUT	/{account}/{container}/{blob}?comp=block&blockid=...	Upload block
PUT	/{account}/{container}/{blob}?comp=blocklist	Commit blocks
GET	/{account}/{container}/{blob}	Download blob
DELETE	/{account}/{container}/{blob}	Delete blob

Usage with Azure SDK

using Azure.Storage.Blobs;

var connectionString = "DefaultEndpointsProtocol=http;" +
    "AccountName=devstoreaccount1;" +
    "AccountKey=Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw==;" +
    "BlobEndpoint=http://localhost:5000/devstoreaccount1";

var client = new BlobServiceClient(connectionString);
var container = client.GetBlobContainerClient("mycontainer");
await container.CreateIfNotExistsAsync();

var blob = container.GetBlobClient("myblob.txt");
await blob.UploadAsync(BinaryData.FromString("Hello, World!"));

Development

Swagger UI

Access Swagger UI at https://localhost:5001/swagger (development mode only).

Logs

Logs are written to:

• Console (all levels)
• logs/blobserver-{date}.log (Warning+ as JSON)

License

Apache License 2.0 - See LICENSE for details.