Since I started using Snap packages a whole ten minutes ago, I'm now wondering, how do you update snap packages?

With Debain's traditional way of upgrading, all you'd do was run apt update && apt upgrade and that would upgrade everything that was upgradable.

The answer...

According to the first Google result I clicked on for the query "how to update snap packages", you don't need to do anything to update snap packages.

And the reason you don't need to do anything to upgrade snap packages is because "Snap packages are automatically updated".

The above mentioned link also says that "And installed Snap packages normally checks for updates four times a day and then installs it automatically."

So here we have a package system that automatically keeps things updated.

My concern is that a package might be broken or have other bugs and I might not want upgrades to happen automatically. Maybe I'd like to disable automatic upgrades. Searching for how to disable a snap package from upgrading isn't yielding any answers. It also seems that in Snap lingo, the word "upgrade" is replaced with the word "refresh". 

It's kind of crazy that there seems to be no way to prevent a package from being upgraded like you could do with the .deb and apt way of doing things.

I found a workaround that someone came up with to prevent the lxd snap package from being upgraded. It looks effective, but it's a dirty workaround.

It basically involves setting the following Snap configuration to mess with the snap proxy:

snap set system proxy.http=""
snap set system proxy.https=""

Or the following IPTables commands are suggested:

iptables -F
iptables -A OUTPUT -d -j DROP

But that's just going to kill snap updates all together. How come it's not possible to hold any specific package(s) back from upgrade with this Snap system? Wouldn't that be Snappy?

Anyway, if you want to see some discussion on the above mentioned workarounds take a look at it on this topic called "Disable snap auto refresh immediately!" on the LXD - Linux Containers Forum. The workarounds are not LXD specific so you should be able to use them to disable all snap updates.