Allow ignoring environment config if it does not exists

[duizabojul]

What problem are you facing?

I don't know if I am using environment config the bad way but I can't figure how to ignore selection of an EnvironmentConfig if it does not exists.

Let's say I have the following EnvironmentConfig resources:

apiVersion: apiextensions.crossplane.io/v1alpha1
kind: EnvironmentConfig
metadata:
  labels:
    provider-name: default-provider
  name: defaut-provider-config
data:
  id: 123456

apiVersion: apiextensions.crossplane.io/v1alpha1
kind: EnvironmentConfig
metadata:
  labels:
    provider-name: other-provider
  name: other-provider-config
data:
  id: 456789

Then I have a XRD with an optional field providerConfigRef.name in spec

In my composition I want to load the default-provider-config EnvironmentConfig if providerConfigRef.name is not referenced in my XR, and the correct provider EnvironmentConfig if it is referenced (let's say other-provider-config EnvironmentConfig if providerConfigRef.name : other-provider).

So I tried to add the following environment in the associated composition:

...
environment:
  environmentConfigs:
    - type: Selector
      selector:
        matchLabels:
        - key: provider-name
          type: Value
          value: default-provider
    - type: Selector
      selector:
        matchLabels:
        - key: provider-name
          type: FromCompositeFieldPath
          valueFromFieldPath: spec.providerConfigRef.name

The problem is if spec.providerConfigRef.name does not exists, crossplane will fail reconciliation with the following message: cannot select environment: failed to build reference at index 1: failed to resolve value for label at index 0: spec.providerConfigRef: no such field

How could Crossplane help solve your problem?

Maybe there is a workaround to this issue, but if not it would be neat to have a way to ignore missing environment config, the same way as patches are ignored if field path does not exists

[negz]

CC @MisterMX

[github-actions]

Crossplane does not currently have enough maintainers to address every issue and pull request. This issue has been automatically marked as stale because it has had no activity in the last 90 days. It will be closed in 14 days if no further activity occurs. Leaving a comment starting with /fresh will mark this issue as not stale.

[bobh66]

/fresh

[phisco]

This was addressed introducing spec.environment.policy.resolution: Optional (default: Required) by: #3981

[phisco]

Actually not, I misread the issue, this is still valid

[MisterMX]

A workaround here in conjuction with #3981 is to use selector instead of ref which can be defined to be optional.

There is currently no way to make a ref optional but it could be made so by adding a policy.resolutionPolicy that works just like provider referencers and can be set to Required (default) or Optional where the latter would could a Not found to be ignored.

[phisco]

@MisterMX i also thought that was the issue, but here the point was actually the missing field in the source composite resource: failed to build reference at index 1: failed to resolve value for label at index 0: spec.providerConfigRef: no such field. Which I'm addressing in #4547.