Overriding LAVA_URL in gitlab CI job does not work

[sre]

Hi,

I have a Gitlab project, which runs multiple lava tests, but needs two different LAVA instances. The first one is specified via LAVA_URL and LAVA_TOKEN in the CI settings. For the second one I tried overriding like this to use STAGING_LAVA_URL instead. The Gitlab CICD Variable precedence suggested, that this should be possible: link to documentation.

lava sige5 test:
  stage: lava
  variables:
    LAVA_URL: ${STAGING_LAVA_URL}
    LAVA_TOKEN: ${STAGING_LAVA_TOKEN}
  tags:
    - lava-runner
  script:
    - submit lava/sige5-testjob.yaml

https://gitlab.collabora.com/hardware-enablement/rockchip-3588/linux/-/pipelines/136125

[sre]

I found the following workaround:

1. Create production and staging environments in Gitlab via WebUI sidebar -> Project -> Operate -> Environments. IIUIC they are mostly intended to be used for Kubernetes deployments.
2. Configure LAVA_URL and LAVA_TOKEN twice with the different values for staging and production, but limit them to the specific Environment
3. In .gitlab-ci.yml set either environment: production or environment: staging for the job to have the right variables set

The disadvantage is, that there is no default. I.e. without specifying any environment it will not have the variable at all. So one needs to make sure all branches get the environment specified in their .gitlab-ci.yml. This can be annoying, if the need for two different LAVA instances only appears after some time. Also I'm not sure if using an environment for this is considered a hack?