Add ingress class name configuration

[pradithya]

What this PR does / why we need it:
To allow selecting specific ingress controller when using RawDeployment

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #2048

Type of changes
Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

Feature/Issue validation/testing:

• Run the controller with and without ingress class name in cluster and create inference service

• Logs
  Ingress generated when ingress class name is set to "istio"

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
    queue.sidecar.serving.knative.dev/resourcePercentage: "20"
  creationTimestamp: "2022-02-18T09:48:52Z"
  generation: 1
  name: xgboost-sample-413
  namespace: test
  resourceVersion: "10446008"
  uid: 79862c9c-e97f-4da9-9d58-e39a0b5481b5
spec:
  ingressClassName: istio
  rules:
  - host: xgboost-sample-413-test.example.com
    http:
      paths:
      - backend:
          service:
            name: xgboost-sample-413-predictor-default
            port:
              number: 80
        path: /
        pathType: Prefix
  - host: xgboost-sample-413-predictor-default-test.example.com
    http:
      paths:
      - backend:
          service:
            name: xgboost-sample-413-predictor-default
            port:
              number: 80
        path: /
        pathType: Prefix

Checklist:

• Have you added unit/e2e tests that prove your fix is effective or that this feature works?
• Has code been commented, particularly in hard-to-understand areas?
• Have you made corresponding changes to the documentation?

Release note:

Add `ingressClassName` configuration to allow selecting specific ingress controller for RawDeployment

[aws-kf-ci-bot]

Hi @pradithya. Thanks for your PR.

I'm waiting for a kserve member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[yuzisun]

/ok-to-test

[yuzisun]

Thanks @pradithya for the contribution!

[yuzisun]

what happens when IngressClassName is nil?

[pradithya]

If it's nil all IngressClassName will be empty and will use default ingress in the cluster (https://kubernetes.io/docs/concepts/services-networking/ingress/#default-ingress-class) . In GKE case it will use create Google Ingress. But essentially it will behave the same as existing behaviour.

If inference service owner want to use specific ingress then they'll have to add ingress class annotation (kubernetes.io/ingress.class)

[yuzisun]

We can default the IngressClassName to istio and add a comment that only for RawDeployment we allow other ingress option currently.

Let's set the default to the config and the test config, add a test case without using the ingress class annotation.

[pradithya]

I updated istio as default ingress class name. We'll need to add the istio ingressClass creation (https://istio.io/latest/docs/tasks/traffic-management/ingress/kubernetes-ingress/#specifying-ingressclass) in the documentation since it's not created by default.

[pradithya]

Updated the test too

[pradithya]

PR for doc update kserve/website#113

[pradithya]

The last e2e fails are unrelated to the PR

FAILED predictor/test_multi_model_serving.py::test_mms_sklearn_kserve[v2-gs://seldon-models/sklearn/mms/lr_model]
FAILED predictor/test_xgboost.py::test_xgboost_v2_runtime_kserve - requests.e...

[pradithya]

/retest

[pradithya]

@yuzisun Ready to be reviewed again

[pradithya]

Removing this annotation from test as it causes some errors:

annotations.kubernetes.io/ingress.class: Invalid value: \"istio\": can not be set when the class field is also set

Somehow the cluster or istio rejects when both ingressClassName and annotations.kubernetes.io/ingress.class are being set.

[yuzisun]

Thanks @pradithya !

/lgtm
/approve

[kserve-oss-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pradithya, yuzisun

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