HMAC File Server Release Notes

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.

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.

---

Installation

Prerequisites

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

Clone and Build

git clone https://github.com/your-repo/hmac-file-server.git
cd hmac-file-server
go build -o hmac-file-server main.go

---

Configuration

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

Server Configuration

Key	Description	Example
ListenPort	Port or Unix socket to listen on	":8080"
UnixSocket	Use a Unix socket (true/false)	false
Secret	Secret key for HMAC authentication	"your-secret-key"
StoragePath	Directory to store uploaded files	"/mnt/storage/hmac-file-server"
LogLevel	Logging level (info, debug, etc.)	"info"
LogFile	Log file path (optional)	"/var/log/hmac-file-server.log"
MetricsEnabled	Enable Prometheus metrics (true/false)	true
MetricsPort	Prometheus metrics server port	"9090"
FileTTL	File Time-to-Live duration	"168h0m0s"
DeduplicationEnabled	Enable file deduplication based on hashing	true
MinFreeBytes	Minimum free space required on storage path (in bytes)	104857600

Uploads

Key	Description	Example
ResumableUploadsEnabled	Enable resumable uploads	true
ChunkedUploadsEnabled	Enable chunked uploads	true
ChunkSize	Chunk size for chunked uploads (bytes)	1048576
AllowedExtensions	Allowed file extensions for uploads	[".png", ".jpg"]

Time Settings

Key	Description	Example
ReadTimeout	HTTP server read timeout	"2h"
WriteTimeout	HTTP server write timeout	"2h"
IdleTimeout	HTTP server idle timeout	"2h"

ClamAV Configuration

Key	Description	Example
ClamAVEnabled	Enable ClamAV virus scanning (true)	true
ClamAVSocket	Path to ClamAV Unix socket	"/var/run/clamav/clamd.ctl"
NumScanWorkers	Number of workers for file scanning	2

Redis Configuration

Key	Description	Example
RedisEnabled	Enable Redis integration	true
RedisDBIndex	Redis database index	0
RedisAddr	Redis server address	"localhost:6379"
RedisPassword	Password for Redis authentication	""
RedisHealthCheckInterval	Health check interval for Redis	"30s"

Workers and Connections

Key	Description	Example
NumWorkers	Number of upload workers	2
UploadQueueSize	Size of the upload queue	50

---

Running the Server

Basic Usage

Run the server with a configuration file:

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

Metrics Server

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

---

Development Notes

• Versioning: Enabled via EnableVersioning. Ensure MaxVersions is set appropriately to prevent storage issues.
• File Cleaner: The file cleaner runs hourly and deletes files older than the configured FileTTL.
• Redis Health Check: Automatically monitors Redis connectivity and logs warnings on failure.

---

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.

---

Monitoring

Prometheus metrics include:

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

---

Example config.toml

[server]
listenport = "8080"
unixsocket = false
storagepath = "/mnt/storage/"
loglevel = "info"
logfile = "/var/log/file-server.log"
metricsenabled = true
metricsport = "9090"
DeduplicationEnabled = true
filettl = "336h" # 14 days
minfreebytes = 104857600 # 100 MB in bytes

[timeouts]
readtimeout = "4800s"
writetimeout = "4800s"
idletimeout = "24h"

[security]
secret = "example-secret-key"

[versioning]
enableversioning = false
maxversions = 1

[uploads]
resumableuploadsenabled = true
chunkeduploadsenabled = true
chunksize = 8192
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"]

[clamav]
clamavenabled = true
clamavsocket = "/var/run/clamav/clamd.ctl"
numscanworkers = 2

[redis]
redisenabled = true
redisdbindex = 0
redisaddr = "localhost:6379"
redispassword = ""
redishealthcheckinterval = "120s"

[workers]
numworkers = 2
uploadqueuesize = 50

This configuration file is set up with essential features like Prometheus integration, ClamAV scanning, and file handling with deduplication and versioning options. Adjust the settings according to your infrastructure needs.

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.

This release ensures an efficient and secure file management system, suited for environments requiring high levels of data security and availability.