rclone/cmd/serve/http/http.go
Nick Craig-Wood 629c0d0f65 serve http: fix serving files of unknown length
Before this change serving files of unknown length were always
returned as 0 length files.

This change serves them correctly, but does not support Range:
requests on them.

See: https://forum.rclone.org/t/serve-http-behavior-when-the-size-is-unknown/21319
2020-12-27 22:01:41 +00:00

232 lines
5.9 KiB
Go

package http
import (
"io"
"net/http"
"os"
"path"
"strconv"
"strings"
"time"
"github.com/rclone/rclone/cmd"
"github.com/rclone/rclone/cmd/serve/httplib"
"github.com/rclone/rclone/cmd/serve/httplib/httpflags"
"github.com/rclone/rclone/cmd/serve/httplib/serve"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/accounting"
"github.com/rclone/rclone/vfs"
"github.com/rclone/rclone/vfs/vfsflags"
"github.com/spf13/cobra"
)
func init() {
httpflags.AddFlags(Command.Flags())
vfsflags.AddFlags(Command.Flags())
}
// Command definition for cobra
var Command = &cobra.Command{
Use: "http remote:path",
Short: `Serve the remote over HTTP.`,
Long: `rclone serve http implements a basic web server to serve the remote
over HTTP. This can be viewed in a web browser or you can make a
remote of type http read from it.
You can use the filter flags (e.g. --include, --exclude) to control what
is served.
The server will log errors. Use -v to see access logs.
--bwlimit will be respected for file transfers. Use --stats to
control the stats printing.
` + httplib.Help + vfs.Help,
Run: func(command *cobra.Command, args []string) {
cmd.CheckArgs(1, 1, command, args)
f := cmd.NewFsSrc(args)
cmd.Run(false, true, command, func() error {
s := newServer(f, &httpflags.Opt)
err := s.Serve()
if err != nil {
return err
}
s.Wait()
return nil
})
},
}
// server contains everything to run the server
type server struct {
*httplib.Server
f fs.Fs
vfs *vfs.VFS
}
func newServer(f fs.Fs, opt *httplib.Options) *server {
mux := http.NewServeMux()
s := &server{
Server: httplib.NewServer(mux, opt),
f: f,
vfs: vfs.New(f, &vfsflags.Opt),
}
mux.HandleFunc(s.Opt.BaseURL+"/", s.handler)
return s
}
// Serve runs the http server in the background.
//
// Use s.Close() and s.Wait() to shutdown server
func (s *server) Serve() error {
err := s.Server.Serve()
if err != nil {
return err
}
fs.Logf(s.f, "Serving on %s", s.URL())
return nil
}
// handler reads incoming requests and dispatches them
func (s *server) handler(w http.ResponseWriter, r *http.Request) {
if r.Method != "GET" && r.Method != "HEAD" {
http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
return
}
w.Header().Set("Accept-Ranges", "bytes")
w.Header().Set("Server", "rclone/"+fs.Version)
urlPath, ok := s.Path(w, r)
if !ok {
return
}
isDir := strings.HasSuffix(urlPath, "/")
remote := strings.Trim(urlPath, "/")
if isDir {
s.serveDir(w, r, remote)
} else {
s.serveFile(w, r, remote)
}
}
// serveDir serves a directory index at dirRemote
func (s *server) serveDir(w http.ResponseWriter, r *http.Request, dirRemote string) {
// List the directory
node, err := s.vfs.Stat(dirRemote)
if err == vfs.ENOENT {
http.Error(w, "Directory not found", http.StatusNotFound)
return
} else if err != nil {
serve.Error(dirRemote, w, "Failed to list directory", err)
return
}
if !node.IsDir() {
http.Error(w, "Not a directory", http.StatusNotFound)
return
}
dir := node.(*vfs.Dir)
dirEntries, err := dir.ReadDirAll()
if err != nil {
serve.Error(dirRemote, w, "Failed to list directory", err)
return
}
// Make the entries for display
directory := serve.NewDirectory(dirRemote, s.HTMLTemplate)
for _, node := range dirEntries {
if vfsflags.Opt.NoModTime {
directory.AddHTMLEntry(node.Path(), node.IsDir(), node.Size(), time.Time{})
} else {
directory.AddHTMLEntry(node.Path(), node.IsDir(), node.Size(), node.ModTime().UTC())
}
}
sortParm := r.URL.Query().Get("sort")
orderParm := r.URL.Query().Get("order")
directory.ProcessQueryParams(sortParm, orderParm)
// Set the Last-Modified header to the timestamp
w.Header().Set("Last-Modified", dir.ModTime().UTC().Format(http.TimeFormat))
directory.Serve(w, r)
}
// serveFile serves a file object at remote
func (s *server) serveFile(w http.ResponseWriter, r *http.Request, remote string) {
node, err := s.vfs.Stat(remote)
if err == vfs.ENOENT {
fs.Infof(remote, "%s: File not found", r.RemoteAddr)
http.Error(w, "File not found", http.StatusNotFound)
return
} else if err != nil {
serve.Error(remote, w, "Failed to find file", err)
return
}
if !node.IsFile() {
http.Error(w, "Not a file", http.StatusNotFound)
return
}
entry := node.DirEntry()
if entry == nil {
http.Error(w, "Can't open file being written", http.StatusNotFound)
return
}
obj := entry.(fs.Object)
file := node.(*vfs.File)
// Set content length if we know how long the object is
knownSize := obj.Size() >= 0
if knownSize {
w.Header().Set("Content-Length", strconv.FormatInt(node.Size(), 10))
}
// Set content type
mimeType := fs.MimeType(r.Context(), obj)
if mimeType == "application/octet-stream" && path.Ext(remote) == "" {
// Leave header blank so http server guesses
} else {
w.Header().Set("Content-Type", mimeType)
}
// Set the Last-Modified header to the timestamp
w.Header().Set("Last-Modified", file.ModTime().UTC().Format(http.TimeFormat))
// If HEAD no need to read the object since we have set the headers
if r.Method == "HEAD" {
return
}
// open the object
in, err := file.Open(os.O_RDONLY)
if err != nil {
serve.Error(remote, w, "Failed to open file", err)
return
}
defer func() {
err := in.Close()
if err != nil {
fs.Errorf(remote, "Failed to close file: %v", err)
}
}()
// Account the transfer
tr := accounting.Stats(r.Context()).NewTransfer(obj)
defer tr.Done(r.Context(), nil)
// FIXME in = fs.NewAccount(in, obj).WithBuffer() // account the transfer
// Serve the file
if knownSize {
http.ServeContent(w, r, remote, node.ModTime(), in)
} else {
// http.ServeContent can't serve unknown length files
if rangeRequest := r.Header.Get("Range"); rangeRequest != "" {
http.Error(w, "Can't use Range: on files of unknown length", http.StatusRequestedRangeNotSatisfiable)
return
}
n, err := io.Copy(w, in)
if err != nil {
fs.Errorf(obj, "Didn't finish writing GET request (wrote %d/unknown bytes): %v", n, err)
return
}
}
}