sshfs is failing with "remote host has disconnected"

Question

I'm running sshfs with the following:

sshfs [email protected]:/var/www/myapp /home/basicuser/code -o sftp_server="/usr/bin/sudo /usr/libexec/openssh/sftp-server"

I have also created RSA keys so I can log in via ssh without password prompt (I tested this and it works).

I have also added the user to the sudoers file to run the sftp-server without a password:

basicuser  ALL=(ALL)  NOPASSWD:  /usr/libexec/openssh/sftp-server

What could be causing this error? How do I figure that out?

Edit

I am trying to mount a folder on the local computer from the remote server. On the remote server, only root has read/write permissions to that folder.

Remote folder: /var/www/myapp (is root only read/write)

Solution 1

It was requiring tty (this basically means something cannot be run in the background, but needs an active terminal window to run). So I added the following to /etc/sudoers (edited by doing visudo):

Defaults:basicuser !requiretty

I want it to not require tty only for that one command, but it may not be possible to do that: https://unix.stackexchange.com/a/80159

Solution 2

You get a lot more information about the failure if you run sshfs as:

sshfs -odebug,sshfs_debug,loglevel=debug user@host ...

Usually this will give you something a lot more helpful to debug the problem.

Comments

[Dan D.]

Why do you need sftp-server on the server to run as root?

[Don Rhummy]

@DanD. The folder that I'll be mounting on the local computer is root-only on the remote server.

[Don Rhummy]

why are you posting this as an answer? this should be a comment on his answer

[codenamejames]

It is an answer to remote host disconnected question. What could be causing this error? How do I figure that out? It just didn't happen to be the answer the OP was looking for. However i had the same question and this was my answer.

[Abandoned Cart]

@codenamejames The process to determine your specific issue was the answer. Your comment is orphaned and forces others to backtrack your "answer" to the one that will actually help the other 90% of users without a broken Blowfish cipher.