No Ubuntu installation possible due to missing SSH key

[Ralf]

I tried to install ubuntu-core-16 on my RaspberryPI 3.
The installation process forced me to create an ubuntu online accout (WTF!?).
After doing this because i thought it will be faster than downloading a different distribution image, I got the following error Message:

error: while creating user: cannot create user for "E-MAIL-ADDRESS": no ssh keys found

How should I provide an ssh key when I'm still in the installation process?
How should I create an ssh key when there is not even a user created on the system, the key must belong to?

[John Lenton (chipaca)]

Typically you'd have two systems, A and B. Say you want to install ubuntu-core on B. So you create a ssh key pair on A (if you don't have one already), and associate the public key of your user account on A with your online account. You then tell the installer on B about your online account, and then you can ssh in from A without using the private key that corresponds to the public key.

[John Lenton (chipaca)]

er, ignore the "without" there, it was a mis-edit.

[Ralf (grayslash)]

Well, what I initially wanted to have is a System that directly boots into firefox that shows the web frontend of my music management so that I have it on a big screen in my living room.

Anyway. Yes, I have lots of linux systems and it's not a big deal to create a new key.
I could create a pair of keys on my main system and uploading the pub.key before the installation process. Then, after the installation process copying the private key onto the raspberry.
The effort doing this for literally nothing but just passing an unskippable step in the installation process seems to me a far to high. (And I assume that this is the last step to finalize the installation)

I was already annoyed when I had to create an online account like you have to do when using some well-known "evil" operating systems :) . But beeing then still not be able to install Ubuntu just made me overwriting the image by a different distribution.
I think/hope this is not how the installation process is intended to be.