Version v1.49.0

docs/content/commands/rclone_serve_ftp.md

@@ -1,5 +1,5 @@
 ---
-date: 2019-06-20T16:09:42+01:00
+date: 2019-08-26T15:19:45+01:00
 title: "rclone serve ftp"
 slug: rclone_serve_ftp
 url: /commands/rclone_serve_ftp/
@@ -165,6 +165,72 @@ This mode should support all normal file system operations.
 If an upload or download fails it will be retried up to
 --low-level-retries times.
 
+### Auth Proxy
+
+If you supply the parameter `--auth-proxy /path/to/program` then
+rclone will use that program to generate backends on the fly which
+then are used to authenticate incoming requests.  This uses a simple
+JSON based protocl with input on STDIN and output on STDOUT.
+
+There is an example program
+[bin/test_proxy.py](https://github.com/rclone/rclone/blob/master/test_proxy.py)
+in the rclone source code.
+
+The program's job is to take a `user` and `pass` on the input and turn
+those into the config for a backend on STDOUT in JSON format.  This
+config will have any default parameters for the backend added, but it
+won't use configuration from environment variables or command line
+options - it is the job of the proxy program to make a complete
+config.
+
+This config generated must have this extra parameter
+- `_root` - root to use for the backend
+
+And it may have this parameter
+- `_obscure` - comma separated strings for parameters to obscure
+
+For example the program might take this on STDIN
+
+```
+{
+	"user": "me",
+	"pass": "mypassword"
+}
+```
+
+And return this on STDOUT
+
+```
+{
+	"type": "sftp",
+	"_root": "",
+	"_obscure": "pass",
+	"user": "me",
+	"pass": "mypassword",
+	"host": "sftp.example.com"
+}
+```
+
+This would mean that an SFTP backend would be created on the fly for
+the `user` and `pass` returned in the output to the host given.  Note
+that since `_obscure` is set to `pass`, rclone will obscure the `pass`
+parameter before creating the backend (which is required for sftp
+backends).
+
+The progam can manipulate the supplied `user` in any way, for example
+to make proxy to many different sftp backends, you could make the
+`user` be `user@example.com` and then set the `host` to `example.com`
+in the output and the user to `user`. For security you'd probably want
+to restrict the `host` to a limited list.
+
+Note that an internal cache is keyed on `user` so only use that for
+configuration, don't use `pass`.  This also means that if a user's
+password is changed the cache will need to expire (which takes 5 mins)
+before it takes effect.
+
+This can be used to build general purpose proxies to any kind of
+backend that rclone supports.  
+
 
 ```
 rclone serve ftp remote:path [flags]
@@ -174,6 +240,7 @@ rclone serve ftp remote:path [flags]
 
 ```
       --addr string                            IPaddress:Port or :Port to bind server to. (default "localhost:2121")
+      --auth-proxy string                      A program to use to create the backend from the auth.
       --dir-cache-time duration                Time to cache directory entries for. (default 5m0s)
       --dir-perms FileMode                     Directory permissions (default 0777)
       --file-perms FileMode                    File permissions (default 0666)