[RFE] ci-automation: remove requirement for google bucket for running Equinix Metal tests

[t-lo]

Current situation

Kola uses a google bucket for images, ignition configs, and PXE scripts for the Equinix Metal tests.

Impact

The containerised ci-automation aims to reduce infrastructure complexity and to remove the need for the google bucket for non-GCP vendors. Kola's dependency on the bucket is a blocker for that.

Ideal future situation

Kola uses local images / files where applicable, and bincache HTTPS URLs where an internet-reachable server is required.

Implementation options

(note that there might be better / more integrated options than the below)

• Have kola emit configuration files locally and push to bincache in test runner script
• Add optional URL parameters to kola test run and supply bincache URLs, overriding use of a google bucket

[tormath1]

Mantle side is implemented, we now need to implement it on the scripts side, we need:

• a user and a SSH key for uploading contents on the bincache server
• a folder served by a webserver for http/https accessing

[pothos]

I think this should work with the existing bincache SSH user: https://github.com/flatcar-linux/scripts/blob/main/ci-automation/ci_automation_common.sh#L117 The only thing to check is whether the kola Docker container has access or needs the key to be forwarded.

[tormath1]

Changed the assignment to @sayanchowdhury as he started to work on the latest piece. (https://github.com/flatcar/Flatcar/issues/720#issuecomment-1167144583) :muscle: