In order to allow users of Jailed shells to access additional directories one has to create a custom jailed shell mount. The following document outlines the process to be followed in order to create such a custom mount, thereby enabling access for the jailed shell users.
How to Create a Custom Mount
To create a custom mount enabling the users of jailed shells to access any additional directories, one has to follow and execute the steps outlined below:
Using a preferred text editor, one must Create a file, that is, the –
/var/cpanel/jailshell-additional-mounts file.
One must then List each separate directory as an ‘absolute’ or a ‘fully-qualified’ one on separate succeeding lines. For instance, one can list then as follows –
/usr/local/test1 /usr/local/test2 /usr/local/test3
Warning:
One should not append a trailing slash to the directory names or use relative paths in listing them. For instance, if one wishes to specify the /usr/local/test1 directory, then one should not enter the directory name in the list in any of the following ways:
test1/ – for this entry contains a trailing slash after the directory name and would indicate it being a relative directory.
test1 – for this entry would indicate it to be a relative directory.
/usr/local/test1/ – for this entry contains again, a trailing slash.
/usr/local/test1 /usr/local/test2 /usr/local/test3 – for this entry is not listed on separate lines, but on the same line.
This is significant as failing to correctly format the directories in the /var/cpanel/jailshell-additional-mounts might result in a server failure.
Finally, having ensured that all of the directories have been entered and listed correctly, Save the custom mount File.
Note:
It has to be kept in mind that custom mounts are read-only files for jailed shell users.
How to Unmount a Custom Mount
To unmount a custom one has to run or use the ‘unmount’ command and not merely remove an entry from the /var/cpanel/jailshell-additional-mounts file.
For instance, in order to unmount the /usr/local/foo one has to run the following command:
umount /home/virtfs/username/usr/local/foo
It is important to remember that if and when a user logs out of the jailed shell account, the system does not unmount custom mounts.
Note:
One should replace the username with that of the particular cPanel user.
