test/networkd: add wireguard setup

[tormath1]

simple setup to test IP is assigned as expected.

Signed-off-by: Mathieu Tortuyaux mtortuyaux@microsoft.com

---

To be tested with: flatcar-archive/coreos-overlay#2061 - currently it's failing but it works when adding the following section:

storage:
  files:
    - path: /etc/systemd/network/zz-default.network.d/wg.conf
      contents:
        inline: |
          [Match]
          Type=!wireguard

as suggested in the ::coreos-overlay PR.

[jepio]

We could also make the test slightly more realistic, and use 2 vms, check that they can communicate etc, but this should be good enough for now.

[tormath1]

@jepio yeah I also wanted to have an actual provisioning to generate wireguard keys during the boot but it can also be done in a follow-up PR.