@periklis I tried to implement what you suggested in your comment, but when testing this doesn't work for me.
when I add component resources in loki spec, example:

  loki:
    resources:
      compactor:
        limits:
          cpu: 200m
          memory: 200Mi
        requests:
          cpu: 100m
          memory: 100Mi

the operator just updates the CR and changes the resources to resources: {} and the default values are used for compute resources. Do you have any suggestions on how I could debug this?

@periklis I tried to implement what you suggested in your comment, but when testing this doesn't work for me.
when I add component resources in loki spec, example:

  loki:
    resources:
      compactor:
        limits:
          cpu: 200m
          memory: 200Mi
        requests:
          cpu: 100m
          memory: 100Mi

the operator just updates the CR and changes the resources to resources: {} and the default values are used for compute resources. Do you have any suggestions on how I could debug this?

The implemtation in this PR is incomplete to achieve what I suggested, i.e. per component resource requirement settings. A working solution looks like this:

1. Amend the observatorium_types.go like this. I suggest to make the map to a struct because it is more visible for CRD users and the components are fully enumerable without making mistakes with the keys:

type LokiResourcesSpec {
    Compactor *v1.ResourceRequirements
    Distributor *v1.ResourceRequirements
    ...
}
type LokiSpec struct {
    ...
    Resources *LokiResourcesSpec
}

2. Adapt obs-operator.jsonnet to read the new fields from the spec and pass them to the loki jsonnet configuration.

@periklis thanks for your help!
I was able to test this now 👍
This PR depends on observatorium/observatorium#411 for the example manifest generation and default values for loki compute resources. Once that is merged, I will update the jsonnet dependencies in this one and this should be good to go.