Go lang union http.FileSystem
$ go get github.com/gnue/httpfs/unionfs
import "github.com/gnue/httpfs/unionfs"
package main
import (
"github.com/gnue/httpfs/unionfs"
"net/http"
)
func main() {
fs := unionfs.New(http.Dir("A"), http.Dir("B"))
http.Handle("/", http.FileServer(fs))
http.ListenAndServe(":8080", nil)
}
Simple union file system webserver