components.pilot.k8s.replicaCount should not be set when values.pilot.autoscaleEnabled is true

[martinstenhoff]

Bug Description

The default profile provided in 1.14.3 (istio-1.14.3/manifests/profiles/default.yaml) generates a warning message about "incompatible" config settings when used.

$ ./istio-1.14.3/bin/istioctl install -f ./istio-1.14.3/manifests/profiles/default.yaml
components.pilot.k8s.replicaCount should not be set when values.pilot.autoscaleEnabled is true
This will install the Istio 1.14.3 default profile with ["Istio core" "Istiod" "Ingress gateways"] components into the cluster. Proceed? (y/N)

The default for components.pilot (using istioctl profile dump command) seems to be:

pilot:
      enabled: true
      k8s:
        hpaSpec:
          maxReplicas: 5
          metrics:
          - resource:
              name: cpu
              target:
                averageUtilization: 80
                type: Utilization
            type: Resource
          minReplicas: 1
          scaleTargetRef:
            apiVersion: apps/v1
            kind: Deployment
            name: istiod
        replicaCount: 1

Version

istioctl version
no running Istio pods in "istio-system"
1.14.3

kubectl version --short
Flag --short has been deprecated, and will be removed in the future. The --short output will become the default.
Client Version: v1.24.3
Kustomize Version: v4.5.4
Server Version: v1.24.0

Additional Information

Perhaps the profile defaults should've been updated as part of this PR #36928

[howardjohn]

You shouldn't need to pass -f ./manifests/profiles/default.yaml - its the defaults already. I think there is somehow logic to know if the warnings are from the built-in defaults not to warn:

$ istioctl install -f ./manifests/profiles/default.yaml --dry-run
components.pilot.k8s.replicaCount should not be set when values.pilot.autoscaleEnabled is true
^C
$ istioctl install  --dry-run
✔ Istio core installed
✔ Istiod installed
✔ Ingress gateways installed
- Pruning removed resources
^C

These will install the same thing in the end.

That being said, there may be some improvements to be made here as well

[martinstenhoff]

You shouldn't need to pass -f ./manifests/profiles/default.yaml - its the defaults already. I think there is somehow logic to know if the warnings are from the built-in defaults not to warn:

I was actually using a customized profile based on the default profile but hadn't made any changes to the pilot specific config provided in the default which is why it's a bit surprising to get a warning about invalid pilot config.

The default.yaml profile contains:

values.pilot.autoscaleEnabled: true
values.pilot.replicaCount: 1

which appears to be copied to

components.pilot.k8s.replicaCount

Is the values.pilot.replicaCount: 1 value used for something else as well or could it be removed from the default profile?