HMAC File Server

HMAC File Server is a secure, scalable, and feature-rich file server with advanced capabilities like HMAC authentication, resumable uploads, chunked uploads, file versioning, and optional ClamAV scanning for file integrity and security. This server is built with extensibility and operational monitoring in mind, including Prometheus metrics support and Redis integration.

Credits: The HMAC File Server is based on the source code of Thomas Leister's prosody-filer. Many features and design elements have been inspired or derived from this project.

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Features

• HMAC Authentication: Secure file uploads and downloads with HMAC tokens.
• File Versioning: Enable versioning for uploaded files with configurable retention.
• Chunked and Resumable Uploads: Handle large files efficiently with support for resumable and chunked uploads.
• ClamAV Scanning: Optional virus scanning for uploaded files.
• Prometheus Metrics: Monitor system and application-level metrics.
• Redis Integration: Use Redis for caching or storing application states.
• File Expiration: Automatically delete files after a specified TTL.
• Graceful Shutdown: Handles signals and ensures proper cleanup.
• Deduplication: Remove duplicate files based on hashing for storage efficiency.
• Auto-Adjust Worker Scaling: Dynamically optimize HMAC and ClamAV workers based on system resources when enabled.

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Repository

• Primary Repository: GitHub Repository
• Alternative Repository: uuxo.net Git Repository

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Installation

Prerequisites

• Go 1.20+
• Redis (optional, if Redis integration is enabled)
• ClamAV (optional, if file scanning is enabled)

Clone and Build

# Clone from the primary repository
git clone https://github.com/PlusOne/hmac-file-server.git

# OR clone from the alternative repository
git clone https://git.uuxo.net/uuxo/hmac-file-server.git

cd hmac-file-server
go build -o hmac-file-server main.go

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Configuration

The server configuration is managed through a config.toml file. Below are the supported configuration options:

Auto-Adjust Feature

When AutoAdjustWorkers is enabled, the number of workers for HMAC operations and ClamAV scans is dynamically determined based on system resources. This ensures efficient resource utilization.

If AutoAdjustWorkers = true, the values for NumWorkers and NumScanWorkers in the configuration file will be ignored, and the server will automatically adjust these values.

Network Events Monitoring

Setting NetworkEvents = false in the server configuration disables the logging and tracking of network-related events within the application. This means that functionalities such as monitoring IP changes or recording network activity will be turned off.

Precaching

The precaching feature allows the server to pre-cache storage paths for faster access. This can improve performance by reducing the time needed to access frequently used storage paths.

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Example config.toml

[server]
ListenPort = "8080"
UnixSocket = false
StoragePath = "./uploads"
LogLevel = "info"
LogFile = ""
MetricsEnabled = true
MetricsPort = "9090"
FileTTL = "1y"
DeduplicationEnabled = true
MinFreeBytes = "100MB"
AutoAdjustWorkers = true  # Enable auto-adjustment for worker scaling
NetworkEvents = false     # Disable logging and tracking of network-related events
PIDFilePath = "./hmac_file_server.pid"  # Path to PID file
Precaching = true  # Enable pre-caching of storage paths

[timeouts]
ReadTimeout = "480s"
WriteTimeout = "480s"
IdleTimeout = "65s"  # nginx/apache2 keep-alive 60s

[security]
Secret = "changeme"

[versioning]
EnableVersioning = false
MaxVersions = 1

[uploads]
ResumableUploadsEnabled = true
ChunkedUploadsEnabled = true
ChunkSize = "64MB"
AllowedExtensions = [".txt", ".pdf", ".png", ".jpg", ".jpeg", ".gif", ".bmp", ".tiff", ".svg", ".webp", ".wav", ".mp4", ".avi", ".mkv", ".mov", ".wmv", ".flv", ".webm", ".mpeg", ".mpg", ".m4v", ".3gp", ".3g2", ".mp3", ".ogg"]

[downloads]
ResumableDownloadsEnabled = true
ChunkedDownloadsEnabled = true
ChunkSize = "64MB"

[clamav]
ClamAVEnabled = false
ClamAVSocket = "/var/run/clamav/clamd.ctl"
NumScanWorkers = 2
ScanFileExtensions = [".exe", ".dll", ".bin", ".com", ".bat", ".sh", ".php", ".js"]

[redis]
RedisEnabled = false
RedisAddr = "localhost:6379"
RedisPassword = ""
RedisDBIndex = 0
RedisHealthCheckInterval = "120s"

[workers]
NumWorkers = 4
UploadQueueSize = 5000

[file]
FileRevision = 1  # Revision number for file handling

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Running the Server

Basic Usage

Run the server with a configuration file:

./hmac-file-server -config ./config.toml

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Metrics Server

If MetricsEnabled is set to true, the Prometheus metrics server will be available on the port specified in MetricsPort (default: 9090).

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Testing

To run the server locally for development:

go run main.go -config ./config.toml

Use tools like cURL or Postman to test file uploads and downloads.

Example File Upload with HMAC Token

curl -X PUT -H "Authorization: Bearer <HMAC-TOKEN>" -F "file=@example.txt" http://localhost:8080/uploads/example.txt

Replace <HMAC-TOKEN> with a valid HMAC signature generated using the configured Secret.

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Monitoring

Prometheus metrics include:

• File upload/download durations
• Memory usage
• CPU usage
• Active connections
• HTTP requests metrics (total, method, path)

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Additional Features

• Deduplication: Automatically remove duplicate files based on hashing.
• Versioning: Store multiple versions of files and keep a maximum of MaxVersions versions.
• ClamAV Integration: Scan uploaded files for viruses using ClamAV.
• Redis Caching: Utilize Redis for caching file metadata for faster access.
• Auto-Adjust Worker Scaling: Optimize the number of workers dynamically based on system resources.

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Build & Run

1. Clone the repository.
2. Build the server:
   go build -o hmac-file-server cmd/server/main.go
3. Run the server:
   ./hmac-file-server --config ./cmd/server/config.toml