webdav: added an rclone vendor to work with rclone serve webdav

Fixes #7160

backend/webdav/webdav.go

@@ -91,6 +91,9 @@ func init() {
 			}, {
 				Value: "sharepoint-ntlm",
 				Help:  "Sharepoint with NTLM authentication, usually self-hosted or on-premises",
+			}, {
+				Value: "rclone",
+				Help:  "rclone WebDAV server to serve a remote over HTTP via the WebDAV protocol",
 			}, {
 				Value: "other",
 				Help:  "Other site/service or software",
@@ -644,6 +647,10 @@ func (f *Fs) setQuirks(ctx context.Context, vendor string) error {
 		// so we must perform an extra check to detect this
 		// condition and return a proper error code.
 		f.checkBeforePurge = true
+	case "rclone":
+		f.canStream = true
+		f.precision = time.Second
+		f.useOCMtime = true
 	case "other":
 	default:
 		fs.Debugf(f, "Unknown vendor %q", vendor)

cmd/serve/webdav/webdav_test.go

@@ -65,7 +65,7 @@ func TestWebDav(t *testing.T) {
 		// Config for the backend we'll use to connect to the server
 		config := configmap.Simple{
 			"type":   "webdav",
-			"vendor": "owncloud",
+			"vendor": "rclone",
 			"url":    w.Server.URLs()[0],
 			"user":   testUser,
 			"pass":   obscure.MustObscure(testPass),

docs/content/webdav.md

@@ -53,7 +53,9 @@ Choose a number from below, or type in your own value
    \ (sharepoint)
  5 / Sharepoint with NTLM authentication, usually self-hosted or on-premises
    \ (sharepoint-ntlm)
- 6 / Other site/service or software
+ 6 / rclone WebDAV server to serve a remote over HTTP via the WebDAV protocol
+   \ (rclone)
+ 7 / Other site/service or software
    \ (other)
 vendor> 2
 User name
@@ -149,6 +151,8 @@ Properties:
         - Sharepoint Online, authenticated by Microsoft account
     - "sharepoint-ntlm"
         - Sharepoint with NTLM authentication, usually self-hosted or on-premises
+    - "rclone",
+        - rclone WebDAV server to serve a remote over HTTP via the WebDAV protocol,
     - "other"
         - Other site/service or software
 
@@ -379,6 +383,14 @@ For Rclone calls copying files (especially Office files such as .docx, .xlsx, et
 --ignore-size --ignore-checksum --update
 ```
 
+## Rclone
+
+Use this option if you are hosting remotes over WebDAV provided by rclone.
+Read [rclone serve webdav](commands/rclone_serve_webdav/) for more details.
+
+rclone serve supports modified times using the `X-OC-Mtime` header.
+
+
 ### dCache
 
 dCache is a storage system that supports many protocols and

fstest/testserver/init.d/TestWebdavRclone

@@ -12,6 +12,7 @@ start() {
     run rclone serve webdav --user $USER --pass $PASS --addr ${IP}:${PORT} ${DATADIR}
     
     echo type=webdav
+    echo vendor=rclone
     echo url=http://${IP}:${PORT}/
     echo user=$USER
     echo pass=$(rclone obscure $PASS)