Fix resource constraints

[dmotte]

The documentation about postgres_pod_resources says that you can disable the defaults by setting them to zero OR empty string:

Empty string or 0 disables the default.

Source: https://github.com/zalando/postgres-operator/blob/2582b934bfb5bfaba9e5d7116ef270e507c5d6a2/docs/reference/operator_parameters.md#L570-L604

But it's not currently possible to set them to empty string, due to the regular expressions in charts/postgres-operator/crds/operatorconfigurations.yaml.

Also, the enforceMinResourceLimits function currently supports only the empty string case, which is impossible to use due to the aforementioned regexes.

This PR aims to fix these two issues 🙂

[FxKu]

@dmotte thanks! Could you provide also unit tests that cover this "new" behavior so I could also try them on the main branch and see what doesn't work? This would be a great improvement to this PR.

[dmotte]

@FxKu done :slightly_smiling_face: I hope it's ok

[FxKu]

Seems to me that only the schema validation needs to change. It's still good though to add a "0" example to the unit test.

[dmotte]

@FxKu yeah, I think I got your point and you are right :)

Just to double check, correct me if I'm wrong: util.IsSmallerQuantity(somePositiveQuantity, "0") returns false, so isSmaller ends up being false and the limit is not enforced.

Thank you! Fixed in 24df591

[FxKu]

Thanks. Can you also update these files with the new validation pattern:

• CRD Manifest example
• CRD go representation

[dmotte]

@FxKu I think you meant manifests/operatorconfiguration.crd.yaml instead of manifests/postgresql.crd.yaml, so I updated that one instead. Done in 107fe9b :wink: let me know if it's OK or you have other requests

[FxKu]

:+1:

[idanovinda]

👍