Remotely Mounting LUKS Encrypted External Drives on Ubuntu/Fedora

Background is that I have a headless server that I run a Plex Media Server within a Docker container.  The server is running Ubuntu, but I also run a mirrored setup on another machine but use Fedora as the OS.

I have 5 external drives for media storage, and each drive is LUKS encrypted.  Since the servers are headless, I don't have a monitor set up mount the drives after subsequently rebooting the systems.

Here are the steps for mounting LUKS encrypted external drives remotely.

After restarting the server, ssh in.

local_user:$ ssh <remote_user>@<remote_ip_address> -p <remote port>

Once logged in to the remote machine, list all of the partitions using lsblk

remote_user:$ lsblk

The result will look something like

NAME                MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT

sda                   8:0    0   2.7T  0 disk 
└─sda1                8:1    0   2.7T  0 part 
sdb                   8:16   0   3.7T  0 disk 
└─sdb1                8:17   0   3.7T  0 part 
sdc                   8:32   0   3.7T  0 disk 
└─sdc1                8:33   0   3.7T  0 part 
sdd                   8:48   0   3.7T  0 disk 
└─sdd1                8:49   0   3.7T  0 part 
sde                   8:64   0   3.7T  0 disk 
└─sde1                8:65   0   3.7T  0 part 

Next, I need to unencrypt each partition on the drive, so issue the following commands:

remote_user:$ sudo cryptsetup luksOpen /dev/sda1 Drive1
remote_user:$ sudo cryptsetup luksOpen /dev/sdb1 Drive2
remote_user:$ sudo cryptsetup luksOpen /dev/sdc1 Drive3
remote_user:$ sudo cryptsetup luksOpen /dev/sdd1 Drive4
remote_user:$ sudo cryptsetup luksOpen /dev/sde1 Drive5

For my plex installation and mapping, I sort of need to know the contents of each drive so they are mapped to the correct mount points.  Since these 5 drives are located in an external enclosure, I don't know the exact mapping, ie, if sda/sda1 is actually Drive1, or Drive3, or Drive5.

With the partitions unlocked, I need to create the mount directories.  Since these drives normally mount under the /media/remote_user/ (Ubuntu) or /run/media/remote_user/ (Fedora) directories, I need to make the directories there, one for each drive to be mounted.  This is due to the volume bindings in the Docker create file I have setup for each container.

remote_user:$ sudo mkdir /media/remote_user/Drive1
remote_user:$ sudo mkdir /media/remote_user/Drive2
remote_user:$ sudo mkdir /media/remote_user/Drive3
remote_user:$ sudo mkdir /media/remote_user/Drive4
remote_user:$ sudo mkdir /media/remote_user/Drive5

Checking directory owner and group shows that these are root:root since I had to use sudo to create the directories.

remote_user:$ ls -l /media/remote_user
total 20
drwxr-xr-x 2 2 root root 4096 Apr 11 21:42 Drive1
drwxr-xr-x 2 2 root root 4096 Apr 11 21:42 Drive2
drwxr-xr-x 2 2 root root 4096 Apr 11 21:42 Drive3
drwxr-xr-x 2 2 root root 4096 Apr 11 21:42 Drive4
drwxr-xr-x 2 2 root root 4096 Apr 11 21:42 Drive5

Now run a chown and chgrp to change the owner and group to remote_user:remote:user.

remote_user:$ sudo chown remote_user /media/remote_user/Drive*
remote_user:$ sudo chgrp remote_user /media/remote_user/Drive*

And long list the directory to make sure the changes are correct.

remote_user:$ ls -l /media/remote_user
total 20
drwxr-xr-x 2 2 remote_user remote_user 4096 Apr 11 21:42 Drive1
drwxr-xr-x 2 2 remote_user remote_user 4096 Apr 11 21:42 Drive2
drwxr-xr-x 2 2 remote_user remote_user 4096 Apr 11 21:42 Drive3
drwxr-xr-x 2 2 remote_user remote_user 4096 Apr 11 21:42 Drive4
drwxr-xr-x 2 2 remote_user remote_user 4096 Apr 11 21:42 Drive5

Now I can mount the drives.  I do this one by one to check that the mapping is correct.

remote_user:$ sudo mount /dev/mapper/Drive1 /media/remote_user/Drive1
remote_user:$ ls -l /media/remote_user/Drive1
total 8
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media1
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media100

remote_user:$ sudo mount /dev/mapper/Drive2 /media/remote_user/Drive2
remote_user:$ ls -l /media/remote_user/Drive2
total 8
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media2
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media4

remote_user:$ sudo mount /dev/mapper/Drive3 /media/remote_user/Drive3
remote_user:$ ls -l /media/remote_user/Drive3
total 8
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media3
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media5

remote_user:$ sudo mount /dev/mapper/Drive4 /media/remote_user/Drive4
remote_user:$ ls -l /media/remote_user/Drive4
total 8
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media6
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media8

remote_user:$ sudo mount /dev/mapper/Drive5 /media/remote_user/Drive5
remote_user:$ ls -l /media/remote_user/Drive5
total 8
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media7
drwxrwxrwx. 3 remote_user remote_user 4096 May 19 2019 Media9

All 5 drives are unencrypted and mapped to the correct directories for plex to be able to see the media again.  This is good because now I no longer have to drag out a monitor, mouse, and keyboard from the closet whenever I want to restart the system to upgrade a kernel or flush memory.