snap, SSL interception, 18.04 upgrade failure

[GovDude]

I thought I'd try the upgrade from 16.04 to 18.04 today. Unfortunately I didn't get very far. I'm getting the following warning/error:

Your system does not have a connection to the Snap Store...
Do you still want to continue with the upgrade?

Continue [yN]

After some Google searching I've come to suspect that this has to do with the fact that my workstation sits behind our corporate firewall which includes SSL interception. I did a "snap install hello-world" and received

error: cannot install "hello-world": Post https://api.snapcraft.io/v2/snaps/refresh: x509:
certificate signed by unknown authority

This would seem to validate my suspicion. Is there any way to get around this issue?

TIA

[TheFu]

I would test it inside a virtual machine. See what happens.

https://askubuntu.com/questions/1039411/how-can-i-replace-snap-application-such-as-gnome-calculator-with-a-deb has some background.

I'm not a fan of snaps for a few reasons.
Good question. Thanks.

[GovDude]

@TheFu gave me a new chain of things to follow and it turns out that https://bugs.launchpad.net/snappy/+bug/1533899/comments/1 fixed my problem. Note that I had defined my proxies in both my login shell, via export http[s]_proxy and in /etc/environment and that didn't solve the problem. But setting the proxies in the file referenced in the link did fix it.