This provides maximum flexibility with minimal API surface overhead.

## Making changes

## Step 1. Make changes in charts and values.yaml in `manifests` directory

Be sure to provide sufficient documentation and example usage in values.yaml.
If the chart has a `values.schema.json`, that should be updated as well.

## Step 2. Update the istioctl/Operator values

If you are modifying the `gateway` chart, you can stop here.

  //
  // The minimum valid value for expirationSeconds is 600, i.e. 10 minutes.
  //
  // +optional
  optional int32 expirationSeconds = 8;

  // allowedUsages specifies a set of usage contexts the key will be
  // valid for.
  // See:
  // 	https://tools.ietf.org/html/rfc5280#section-4.2.1.3
  // 	https://tools.ietf.org/html/rfc5280#section-4.2.1.12
  //
  // Valid values are:

				shorthand := "   "
				if flag.Shorthand != "" {
					shorthand = "-" + flag.Shorthand + ","
				}
				c.Printf("  %s --%s: %s\n", shorthand, flag.Name, flag.Usage)
			}
		})
	})

	return retval

```

2) `istio-cni` chart installs the CNI plugin. This should be installed after the `base` chart and prior to `istiod` chart. Need to add `--set pilot.cni.enabled=true` to the `istiod` install to enable its usage.

```console
helm install istio-cni -n kube-system manifests/charts/istio-cni --set profile=openshift
```

3) `istio-control/istio-discovery` chart installs a revision of istiod.

```console

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Usage: tracing::extract_prow_trace.
# If running in a prow job, this sets the parent trace to the same value Prow tracing will use, as defined in https://github.com/kubernetes/test-infra/issues/30010
function tracing::extract_prow_trace() {

    # For example: https://$remotePilotAddress:15017/validate
    validationURL: ""
    # Validation webhook caBundle value. Useful when running pilot with a well known cert
    validationCABundle: ""

    # For istioctl usage to disable istio config crds in base
    enableIstioConfigCRDs: true

  defaultRevision: "default"
  experimental:

Aside from this, there are a few conveniences and workarounds built-in to the client to make things simpler.

*All Istio Kubernetes usage should use this library and not operate on Kubernetes clients directly.*