Windows shortcut to map disk with sshfs

Question

I don't want to permanently map remote disks from production systems, I want to click on shortcut to map the disk and than click another shortcut to unmap it. The sshfs works fine when used from Bash. However when I run the command from shortcut with wsl.exe, it maps the disk but as soon as the command ends, mapping is removed. This can be replicated by running wsl.exe from PS:

PS C:\Users\user> wsl.exe --user root -- sshfs -o allow_other,default_permissions,ro user@machine:/path /mnt/path `&`& read -p "Press enter to continue"

After the sshfs is executed, I can see that the disk is mapped but when I press enter, the disk is unmapped. It seems that there is some kind of "console session" and the mapping is related to the session only, once the session ends, the mapping ends.

I have no idea what's going on, I am missing something simple but fundamental. Thank you for any pointers. And no, using bash.exe does not fix the problem.

Answer 1

So I came up with two possible solutions for this. There's the "hard way" that works more like you seem to be expecting, and an "easy way" that works almost like you seem to want.

This is the "hard way", but it's not too bad, really. I'm just verbose ;-) ...

I'm making an assumption that you can at least use a passphrase-protected keypair for connecting, rather than just a simple password. As long as we can get the password/passphrase before launching sshfs, it gets a whole lot easier.

I'm also making an assumption that you are using Ubuntu, but the basic steps here should work in any distribution.

• Set up your ssh keys on the client (WSL) and the server

• Install keychain (sudo apt-get install keychain)

• Install tmux if needed (should already be installed in the default WSL Ubuntu distro)

• Make sure you can connect using keychain/ssh-agent as the user (root in this case). From inside the WSL instance (bash):

  eval $(keychain --eval ~/.ssh/id_rsa) # Should ask for key passphrase
  sshfs -o allow_other,default_permissions,ro user@machine:/path /mnt/path # Should connect without requiring a password or passphrase
  

• Assuming that works, for your "connection script/command" in PowerShell:

  wsl -u root -e bash -c 'eval $(keychain --eval ~/.ssh/id_rsa) tmux new-session -s sshfs -d sshfs -f -o allow_other,default_permissions,ro user@machine:/path /mnt/path'
  

• Your "disconnect script" is:

  wsl -u root umount /mnt/path
  wsl -u root keychain --stop all
  

Breaking that down, the first command:

• Requests your passphrase via keychain so that the sshfs command itself doesn't require any user input.
• Sets up a disconnected tmux session using -d (so WSL keeps running in the background)
• Starts sshfs in the foreground of a window in that tmux session (using -f). However, since the tmux session is disconnected, you won't be able to directly enter the password there; thus the need for keychain above.

When the disconnect is run, it simply unmounts the connection, which causes the sshfs running in that tmux window to exit, thus causing the tmux session and server to end. All that's left to clean up at that point is the ssh-agent left by keychain. Once that's gone, the WSL instance itself will terminate itself, assuming you don't have anything else running in it.

Answer 2

So I came up with two possible solutions for this. There's the "hard way" that works more like you seem to be expecting, and an "easy way" that works almost like you seem to want.

This is the "easy way":

Just run sshfs using the -f flag to keep it from exiting:

wsl -u root sshfs -o allow_other,default_permissions,ro user@machine:/path /mnt/path

That's going to keep a window or PowerShell window open, of course. But if you are setting it up as a shortcut, you could always set it to run Minimized.

To terminate the connection, run:

wsl -u root umount /mnt/path

Once the connection is terminated through unmounting, the sshfs command will exit, and the previous window will close.

Since you already had a similar solution with the read command, I'm guessing that's not quite what you want, though. Hence the "hard way" solution that I provided as well.

Answer 3

I finally settled with the two shortcuts using detached screen and I need to type the password. The two solutions above might work better for someone else but helped me to find my solution.

Mount server:

C:\Windows\System32\wsl.exe --user root -- screen -S "server" bash -c "mkdir -p /mnt/server; sshfs -o allow_other,default_permissions,ro user@server:/folder /mnt/server; echo 'Press Ctrl-a, Ctrl-d'; exec sh;"

Explanation - screen will create new session with name "server" and run the bash command in quotes. Bash will create mount folder (optional), sshfs will prompt for password, echo will ask user to detach the session and exec sh will run indefinitely. The Ctrl-a, Ctrl-d will detach screen and it will run on background.

Umount server:

C:\Windows\System32\wsl.exe --user root -- screen -X -S "server" quit

Explanation - this will quit the detached session and also the sshfs mount,