docs: update vfolder and sftp_to_container page (#34)

* docs: update vfolder and sftp_to_container page
* docs: update help texts in vfolder sftp upload feature
* docs: add a note to link ssh keyapr upload guide

---------

Co-authored-by: Jonghyun Park <jpark@lablup.com>

docs/sftp_to_container/sftp_to_container.rst

@@ -7,21 +7,22 @@ SSH/SFTP Connection to a Compute Session
 Backend.AI supports SSH/SFTP connection to the created compute sessions
 (containers). In this section, we will learn how to do it.
 
-.. note::
-   SSH/SFTP connection is supported only on desktop apps, but not on web-based
-   Web-UI. Desktop app can be downloaded a panel from the Summary page. Using
-   this panel, the compatible version will be downloaded automatically.
+.. .. note::
+..    SSH/SFTP connection is supported only on desktop apps, but not on web-based
+..    Web-UI. Desktop app can be downloaded a panel from the Summary page. Using
+..    this panel, the compatible version will be downloaded automatically.
 
-   .. image:: app_download_panel.png
-      :width: 350
-      :align: center
+..    .. image:: app_download_panel.png
+..       :width: 350
+..       :align: center
 
-   You can also download the app from
-   https://github.com/lablup/backend.ai-webui/releases. Make sure to download
-   the compatible version of the Web-UI in this case. You can check the Web-UI
-   version by clicking on the "About Backend.AI" sub-menu located in the
-   preference menu on the upper-right side of the GUI.
+..    You can also download the app from
+..    https://github.com/lablup/backend.ai-webui/releases. Make sure to download
+..    the compatible version of the Web-UI in this case. You can check the Web-UI
+..    version by clicking on the "About Backend.AI" sub-menu located in the
+..    preference menu on the upper-right side of the GUI.
 
+.. _sftp_connection_for_linux_and_mac:
 
 For Linux / Mac
 ----------------------------------------------------
@@ -90,6 +91,13 @@ each FTP client manual for details.
    connect by SSH/SFTP through your own SSH private key without having to
    download the ``id_container`` after creating a compute session.
 
+.. note::
+   If you receive the following warning message, try again after changing the
+   permission of the ``id_container`` to 600. (``chmod 600 <id_container path>``) 
+
+   .. image:: bad_permissions.png
+      :alt: Permissions Warning Message
+
 
 For Windows / FileZilla
 --------------------------------------------------------------
@@ -174,7 +182,7 @@ For convenience, we set the hostname to ``vscode``. It can be changed to any ali
 
    Host vscode
      HostName 127.0.0.1
-     Port 39447  # write down the port number that you remembered
+     Port 30732  # write down the port number that you remembered
      User work
      ForwardAgent yes
      StrictHostKeyChecking no

docs/user_settings/user_settings.rst

@@ -54,6 +54,8 @@ before the page is refreshed.
    WebUI is open sourced, anyone who willing to make the translation better
    can contribute: https://github.com/lablup/backend.ai-webui.
 
+.. _user-ssh-keypair-management:
+
 SSH Keypair Management
 ^^^^^^^^^^^^^^^^^^^^^^
 

docs/vfolder/vfolder.rst

@@ -95,7 +95,7 @@ well. For more detailed file operations, you can mount this folder when creating
 a compute session, and then use a service like Terminal or Jupyter Notebook to
 do it.
 
-.. image:: vfolder_explorer.png
+.. image:: folderexplorer_with_filebrowser.png
    :alt: File explorer of a storage folder
 
 You can create a new directory on the current path with the NEW FOLDER button
@@ -199,8 +199,7 @@ Execute FileBrowser from folder explorer dialog in Data & Storage page
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Go to the Data & Storage page and open the file explorer dialog of target
-data folder. Click the folder icon in the Control column to the right of the
-data folder to open the file explorer.
+data folder. Click the folder icon or the folder name to open the file explorer.
 
 .. image:: first_step_to_access_filebrowser.png
    :alt: first step to access FileBrowser
@@ -325,6 +324,47 @@ You will see that moving operation is successfully finished.
    We are planning to update FileBrowser so that it can run independently
    without creating a session.
 
+Using SFTP Server
+-----------------
+
+From 22.09, Backend.AI supports SSH / SFTP file upload from both desktop app and
+web-based Web-UI. The SFTP server allows you to upload files quickly through reliable
+data streams.
+
+.. note::
+   Depending on the system settings, running SFTP server from the file dialog may not
+   be allowed.
+
+Execute SFTP server from folder explorer dialog in Data & Storage page
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Go to the Data & Storage page and open the file explorer dialog of target data folder.
+Click the folder icon or the folder name to open the file explorer.
+
+Click RUN SFTP SERVER button in the upper-right corner of the explorer.
+
+.. image:: folderexplorer_with_filebrowser.png
+   :alt: Folder explorer with SFTP Server
+
+You can see the SSH / SFTP connection dialog. And a new SFTP session will be created
+automatically. (This session will not affect resource occupancy.)
+
+.. image:: SSH_SFTP_connection.png
+   :height: 500
+   :align: center
+   :alt: SSH / SFTP connection dialog
+
+For the SSH connection, click "DOWNLOAD SSH KEY" button to download the SSH private key
+(``id_container``). Also, remember the host and port number. Then, you can connect to SFTP server
+using the Connection Example code written in the dialog, or you can connect to SSH / SFTP
+by referring to the following :ref:`link<sftp_connection_for_linux_and_mac>`.
+
+.. note::
+   If you upload your SSH keypair, the ``id_container`` will be set with your
+   own SSH private key. So, you don't need to download it every time you
+   want to connect via SSH to your container. Please refer to
+   :ref:`manageing user's SSH keypair<user-ssh-keypair-management>`.
+
 
 Setting quota on XFS
 --------------------