An encrypted /home directory gets mounted automatically for me when I log in. I have a second internal hard drive that I've formatted and encrypted with Disk Utility. I want it to be automatically mounted when I login, just like my encrypted /home directory is. How do I do this?

There are several very similar questions here, but the answers don't apply to my situation. It might be best to close/merge my question here and edit the second one below, but I think it may have been abandoned (and therefore never to be marked as accepted).

This solution isn't a secure method, it circumvents the encryption.
This one requires editing fstab, which necessitates entering an additional password at boot. It's not automatic like mounting /home.
This question is very similar, but does not apply to an encrypted drive. The solution won't work for my needs.
Here is one but it's for NTFS drives, mine is ext4.

I can re-format and re-encrypt the second drive if a solution requires this. I've got all the data backed up elsewhere.