no way to avoid CDN for snap store within launchpad builds

[Steve Langasek]

There was discussion on this in an internal Canonical RT ticket, but I haven't seen a public bug about this issue, so filing this one.

https://rt.admin.canonical.com/Ticket/Display.html?id=98451

Automated builds of ubuntu-core images on production infrastructure - i.e. Launchpad - requires that Launchpad builders be able to download snap packages from the snap store. This is currently not possible because Launchpad image and .deb package builds have a restrictive firewall by design, which is incompatible with the use of a CDN for the snap store. We need a resolution that makes it possible for launchpad to download snaps as part of image builds, not just for ubuntu-core images, but also for other classic image builds where we want snaps to be pre-installed or locally cached.

[Michael Vogt (mvo)]

Added a server task, hope I got it right (not sure if its click-package-index or software-center-agent or something else). @store-team: if I got it wrong, please retarget appropriately.

[Steve Langasek (vorlon)]

Per discussion with Celso, it should be possible for the store to not redirect to the CDN when the request comes from Launchpad.

[Jamie Bennett (jamiebennett)]

What is the timeframe for this change?

[Celso Providelo (cprov)]

Jamie and Steve,

We have just released support for `SNAPPY_STORE_NO_CDN=1 snap install foo` in the Store. Tested with snapd 2.21.