Automatic access to remote storage

Problem description

I’ve got a remote resource with data that can be accessed with sshfs. So I can write a simple script for automatic mounting of this volume.

Caution!: The approach presented below is not very safe and shouldn’t be recommended as a proper way of handling logging due to storing password in a text file! If you have the possibility of logging with the use of GPG keys you should apply it.

Mounting

#!/bin/bash

## Caution: Sourcing this script like this:
## . mountCloud.sh
## can be useful when running the script in the command line!

absPath=/home/mb/
mountingDir="$absPath"pcloud ; # it could be worth to have here an absolute path 

## allow_other option to let docker container bind remote volumes mounted by sshfs
## https://serverfault.com/questions/947182/mount-a-sshfs-volume-into-a-docker-instance

echo 'password' | sshfs -p 12345 user@address.something.org:/ $mountingDir -o password_stdin

## if necessary:
# cd "$mountingDir"/specific/path

Remark:

Instead of running this script it may be useful to source it and to make changes made inside script stay in your current shell (link 1, link 2). Sourcing can be perfomed with the command source mountCloud.sh or simple with the use of dot: Remark 2: allow_other option lets docker container bind remote volumes mounted by sshfs (Link)

Umounting

#!/bin/bash

## Caution: Sourcing this script like this:
## . umountCloud.sh
## can be useful when running the script in the command line!
# ____________________________________________________________________________78

absPath=/home/mb/
mountingDir="$absPath"pcloud ; # it could be worth to have here an absolute path 

## Auxiliary variables for logging purposes:
## Get current date ##
_now=$(date +"%Y_%m_%d_%H_%M_%S")

_logfileStub="$absPath"temp/UmountCloud

# if the resource is mounted
if mount | grep $mountingDir > /dev/null; then 
    echo "Volume is mounted."

    # if non-sudo unmounting fails
    if ! umount $mountingDir; then
        xmessage -center "$mountingDir could not be unmounted! Free resources and try again." -timeout 3
        echo "$mountingDir could not be unmounted! Free resources and try again."
        touch "$_logfileStub"-"$_now"-umount-fail.log

        # try sudo and forced unmounting
        if ! sudo umount -f $mountingDir; then
            # if it fails 
            # volume remains mounted - there will be problems after
            # hibernation or going to sleep
            xmessage -center "pcloud could not be unmounted FORCEfully! This is a real problem." -timeout 3
            echo "Unmounted after unmounting WITH force"
            touch "$_logfileStub"-"$_now"-umount-With-Force-fail.log
        else
            # If it succeeds
            # volume is unmounted - however $mountingDir
            # probably becomes corrupted in such case.
            echo "Volume unmounted forcefully".
            touch "$_logfileStub"-"$_now"-umount-With-Force-Success.log

            # umount one more time, now without a force to 
            # to free resources and to make 
            # a mounting directory which is corrupted after 
            # force umounting be uncorrupted.
            # This may fail if $mountingDir is still opened in the command line
            # or in window manager (for instance: Dolphin)
            # It may be needed to run the command below after
            # closing all windows with opened with $mountingDir directory
            sudo umount $mountingDir
        fi
    else
        echo "Volume unmounting succeded."
        touch "$_logfileStub"-"$_now"-umount-Success.log
    fi

else
    echo "Volume is NOT mounted."
    touch "$_logfileStub"-"$_now"-not-Mounted-At-all.log
fi

/dev/null is a system’s black hole and redirecting the stream to it makes the output of the command that would normally appear in the command line… not appear on the screen.

The above script works as follows:

if the volume is unmounted it does nothing
if the volume is mounted it:
- tries to unmount it gently
  - if that fails it tries to umount with -f flag
    - if that fails then we’ve got a problem – there is a big chance that after restarting the computer after sleep/hibernation the system hangs

In order have unmounting process going automatically we need to put the following script in /usr/lib/systemd/system-sleep/ (true for Debian Bullseye, this path may be different in various Debian versions and various Linux distribution) and (don’t forget about this point!) perform:

chmod +x /lib/systemd/system-sleep/umountCloud_usr_lib_systemd_system-sleep

Have in mind that the number at the beginning of the filename is file’s priority (order of the execution when sleep action is invoked).

#!/bin/bash

# put it in  
# /usr/lib/systemd/system-sleep/
# and DON'T FORGET TO!:
# chmod +x /lib/systemd/system-sleep/55umountPionierCloud_etc_pm_sleepd 

absPath=/home/mb/
mountingDir="$absPath"pcloud ; # an absolute path is required since this
                           # script is run from root context!

## Auxiliary variables for logging purposes:
## Get current date ##
_now=$(date +"%Y_%m_%d_%H_%M_%S")
## information just for specific user
_logfileStub="$absPath"temp/sys-sleep

case "$1" in
    pre)
        # Place your pre suspend commands here, or `exit 0` if no pre suspend action required
        echo "Going to $2..."
        touch "$_logfileStub"-"$_now"-going_to_sleep.log
        . "$absPath"binmb/pionierScripts/umountCloud.sh
        #_file="/home/mb/sleep$_now"
        #    touch $_file   
        # if [ -d "$FOLDER" ]; then
        #     # echo "$FOLDER exist - can be unmounted"
        #     sudo umount /home/mb/pcloud
        #     touch /home/mb/sleepd-umounted.txt
        # else
        #     echo "~/pcloud/home does not exist"
        # fi    
        ;; # semi-colons are important!
    post)
        # Place your post suspend (resume) commands here, or `exit 0` if no post suspend action required
        echo "Waking up from $2..."
        touch "$_logfileStub"-"$_now"-resuming-system.log
        # umount resource in case something went wrong during putting to sleep
        . "$absPath"binmb/pionierScripts/umountCloud.sh
        ;; # semi-colons are important!
esac

After tangling remeber to put the files in the appropriate folders and give them appropriate properties. You do this by tangling the following script and executing it with: . fileDispatching.sh from the context of its parent directory.

#!/bin/bash

absPath=/home/mb/
userScripts="$absPath"binmb/pionierScripts/
localPath=

# mv "$userScripts"mountCloud.sh "$userScripts"mountCloud.shBKP
mv "$userScripts"umountCloud.sh "$userScripts"umountCloud.shBKP  
mv "$userScripts"55umountCloud_usr_lib_systemd_system-sleep "$userScripts"55umountCloud_usr_lib_systemd_system-sleepBKP

# cp ./2023-01-13-auto-mount-umount/mountCloud.sh "$userScripts"mountCloud.sh
cp umountCloud.sh "$userScripts"umountCloud.sh  
cp 55umountCloud_usr_lib_systemd_system-sleep "$userScripts"55umountCloud_usr_lib_systemd_system-sleep

sudo mv /usr/lib/systemd/system-sleep/55umountCloud_usr_lib_systemd_system-sleep /usr/lib/systemd/system-sleep/55umountCloud_usr_lib_systemd_system-sleepBKP
sudo cp "$userScripts"55umountCloud_usr_lib_systemd_system-sleep /usr/lib/systemd/system-sleep/55umountCloud_usr_lib_systemd_system-sleep
sudo chmod +x /usr/lib/systemd/system-sleep/55umountCloud_usr_lib_systemd_system-sleep

remote mount umount cifs volume