xdrrpc (simple-nfs-server) - nfs server the easy way

Overview

simple-nfs-server is an example nfs server implementation that serves files from memory. xdrrpc is a golang library to create XDRRPC services also known as SUNRPC or ONCRPC (RFC 5531). Both are written in pure go, without using rpcgen toolchain (Sun Microsystems ONC RPC generator). xdrrpc conforms to golang net/rpc ServerCodec interface. API documentation for xdrrpc can be found in .

Installation

$ go get -u github.com/dzeromsk/xdrrpc/...

This will make the simple-nfs-server tool available in ${GOPATH}/bin, which by default means ~/go/bin.

Usage

simple-nfs-server serves all files from memory with limited support for attributes.

Usage of simple-nfs-server:
  -debug
        Enable debug prints
  -listen string
        Server listen address (default ":12049")

Example

Start simple-nfs-server

$ simple-nfs-server --debug -listen :12049

Mount on the client using fixed protocol (tcp), port (12049) and any mount point on localhost:

$ sudo mount -vvv -o nfsvers=3,proto=tcp,port=12049,mountvers=3,mountport=12049,mountproto=tcp 127.0.0.1:/ /mnt/example

Low level usage of xdrrpc package

import (
  "net/rpc"
  "github.com/dzeromsk/xdrrpc"
)

func init() {
  xdrrpc.Register(100005, 3, 0, "Mount", "Null")
}

type Mount struct {}

func (m *Mount) Null(args *mount.NullArgs, res *mount.NullRes) error {
	return nil
}

func main() {
	rpc.Register(mount)
	ln, _ := net.Listen("tcp", *listen)
	for {
		conn, _ := ln.Accept()
		go xdrrpc.ServeConn(conn)
	}
}

For helpers like nfs.ServeMux usage please take a look at xdrrpc/nfs and xdrrpc/example/memfs packages. Skimming through RFC 1813 will help too.

Features

• Simple.
• Memory only.
• Compatible with Linux kernel NFS Client.
• Implements stdlib ServerCodec.

Downsides

• Some features are missing.

Philosophy

xdrrpc conforms to golang net/rpc ServerCodec interface. At some point in future we should consider replacing net/rpc with custom RPC server implementation.

I made this to debug Linux NFS Client attribute caching behavior at work. Feel free to fork it.