fsoss

fsoss is a Go library that implements the afero filesystem interface for Aliyun OSS (Object Storage Service).

It allows you to use Aliyun OSS as a backend for any application that uses afero, enabling easy switching between local filesystem, memory filesystem, and OSS.

Installation

go get github.com/techquest-tech/fsoss

Usage

package main

import (
	"fmt"
	"log"
	"os"

	"github.com/spf13/afero"
	"github.com/techquest-tech/fsoss"
)

func main() {
	endpoint := "oss-cn-hangzhou.aliyuncs.com"
	accessKeyID := "your-access-key-id"
	accessKeySecret := "your-access-key-secret"
	bucketName := "your-bucket-name"

	// Create a new OSS filesystem instance
	ossFs, err := fsoss.NewOssFs(endpoint, accessKeyID, accessKeySecret, bucketName)
	if err != nil {
		log.Fatal(err)
	}

	// Use it like any other afero.Fs
	var AppFs afero.Fs = ossFs

	// Create a file
	f, err := AppFs.Create("test.txt")
	if err != nil {
		log.Fatal(err)
	}
	f.WriteString("Hello, Aliyun OSS!")
	f.Close()

	// Read a file
	f, err = AppFs.Open("test.txt")
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()

	b := make([]byte, 100)
	n, _ := f.Read(b)
	fmt.Println(string(b[:n]))

	// Check file info
	fi, err := AppFs.Stat("test.txt")
	if err == nil {
		fmt.Printf("Size: %d, ModTime: %s\n", fi.Size(), fi.ModTime())
	}
}

Features

• Implements afero.Fs interface.
• Uses local temporary files for read/write operations to ensure full compatibility (seeking, partial writes, etc.).
• Uploads changes to OSS only on Close() or Sync().
• Supports directory simulation (OSS prefixes).

Limitations

• Chmod, Chown, Chtimes are no-ops as OSS metadata is different from POSIX attributes.
• Performance: Opening a file downloads it entirely to a local temporary file. This ensures compatibility but may be slow for large files if you only need a small part.
• Atomicity: File writes are atomic (put object), but directory operations are not fully atomic.

License

MIT