Mounting / Unmounting encrypted external drive over command line in Ubuntu 18.04

If you have an encrypted external disk (or an internal disk that is not in fstab), you will see an entry for it in Nautilus. You can click on this volume, and am prompted for a password to decrypt and mount the device. However if you want mount and unmount the same over command line.

I follow the below steps to mount and unmount encrypted partitions.

You may require to install cryptsetup first.

sudo apt-get install cryptsetup

To decrypt the volume:

sudo cryptsetup luksOpen /dev/sda1 my_encrypted_volume

Now you can mount it as usual:

sudo mkdir /media/my_device
sudo mount /dev/mapper/my_encrypted_volume /media/my_device

To lock the container again, it needs to be unmounted first:

sudo umount /media/my_device
sudo cryptsetup luksClose my_encrypted_volume

To automatically put it in the /media location, use the udisks tool

sudo udisks --mount /dev/mapper/my_encrypted_volume