Lab servers are not Goobuntu, and our puppet configuration only manages the sshd config for Goobuntu machines. I'm not sure how we got into this state - why did we decide to special case Goobuntu devservers?

No idea, but I think we should control it.

And having read through both sshd configs, I believe the Goobuntu one should work on Ubuntu. However, it's better to test. 

Do we have a way to test puppet config changes on the staging lab servers?

#1 Probably we special cased lab devservers, since they are Ubuntu and probably were added later.

#2 Do we have a way to test puppet config changes on the staging lab servers?

Sort of.  Not that it matter in this case, since there are no lab devservers in the staging lab setup (I think).

Quick notes for things to check:

1. Ubuntu and Goobuntu use which versions of OpenSSH?
2. What are the default values for all of the Goobuntu settings that are missing from Ubuntu?
3. Are there any settings in the Ubuntu config that are not in the Goobuntu config?
3a. Do we merge those settings back?
3aa. What are the default values for those settings in the Goobuntu version of OpenSSH?
3b. Do we drop those settings?
3ba. What are the default values for those settings in the Ubuntu version of OpenSSH?

Alternatively, push it and see if anything breaks.  Much easier.

There is one staging devserver. I believe it's in the lab, though I don't know which machine it is.

Hi, this bug has not been updated recently and remains untriaged. Please acknowledge the bug and provide status within two weeks (6/8/2018), or the bug will be closed. Thank you.