rclone mount volume automatically via bashrc on startup - linux

Question

I am using rclone to mount a folder from my cloudstorage on my local computers. however, on one machine I only connect via terminal and I want to mount the volume on startup.
So I setup a small shell-script with following contents:
rclone mount remoterep:/examplefolder ~/Documents/examplefolder
and I call it in bashrc with exec ~/mount_examplefolder
when I ssh into said computer, it is working as I do not get any errors but the shell refuses to take any further commands as the mount command is executed.
If I add another ssh login, I get an error-prompt, because it can't overwrite the mount folder from the other session.
So how do I fix this, that the rclone is being executed in the background giving me access to shell back?
Or am I restricted to mounting it manually and then using another ssh session to perform the desired actions?

Answer 1

There's a couple of things here that are causing some problems.
First, when you use exec to spawn a process in the shell, that means that you want to replace the existing shell process with the program you've mentioned. When you do that in an SSH session, you replace the shell process that the SSH daemon started (and you were intending to use to log in). SSH will then wait for that process to exit (which it won't until the volume is umounted), which is why you see the hang. You'll want to skip the exec in your shell configuration, which will spawn the process without replacing your shell.
Second, the reason you see the error is that the mount process is designed to be run once, as you've noticed. If you want to skip mounting the folder if it's already mounted, you can use something like the following as your shell script:
#!/bin/sh
if ! grep " $HOME/Documents/examplefolder " /proc/mounts
then
rclone mount remoterep:/examplefolder ~/Documents/examplefolder
fi
Note the spaces inside the quotes that ensure that you haven't matched something else by accident. This will ensure that your script doesn't try to mount multiple times.
Third, you'll probably want to run this command in the background and detached from the shell so that the exit of the shell doesn't cause it to receive SIGHUP and exit (or restart, depending on how it's configured). You can do this by writing the invocation in your shell configuration as nohup ~/mount_examplefolder >/dev/null 2>&1 &. nohup prevents the program from receiving SIGHUP and redirecting output prevents it from printing messages or creating nohup.out files all over the place.
Finally, you may (or may not) want to configure this to run only when you're using an interactive shell; that is, when you're logging in to start a shell for interactive use rather than scripting use. If so, you can make the invocation of nohup condition on PS1 being set like so:
if [ -n "$PS1" ]
then
nohup ~/mount_examplefolder >/dev/null 2>&1 &
fi