Enable strict elemental-setup

[frelon]

The current behavior when including a broken yip config in a system is to ignore any errors and only show errors in journal for the elemental-setup-<stage>.

We should consider enabling the --strict flag to actually show the elemental-setup-<stage> as failed when a configuration is broken (or a command fails).

An initial list of tests to verify the intended behavior, feedback welcome:

• installer runs correctly with broken yip in /oem
• system still boots with broken yip config in /oem
• unmarshal error visible in journalctl
• systemd services show up as failed (part of Enable strict elemental-setup #2216)
• valid yip config that errors out should also show up as an error for the stage (part of Enable strict elemental-setup #2216)

This means that an unparseable yip-config will make all elemental-setup-* services show up as failed in systemd, but the system will still boot correctly.

This example yip config will only show elemental-setup-boot as failed:

stages:
  boot:
    commands:
      - exit 2

[davidcassany]

The question here I what is broken yip. I can imagine three different categories (probably there are more):

• invalid yaml
• valid yaml but invalid scheme
• wrong command (e.g. exit 1 or a command line with a typo)

Invalid yaml IMHO should only cause the file to be ignored and report the unmarshal error to journal.

Wrong command should simply execute everything, including all pending steps and report the error to journal and systemd, causing the offending stage to fail but continue with the boot.

With an invalid scheme I am not sure what it meant to happen what actually happens today in terms of yip.
For now I am trying to code the integration test I had in mind for degraded services.