#
    # certSigners:
    #   - clusterissuers.cert-manager.io/istio-ca
    certSigners: []
    # enable pod disruption budget for the control plane, which is used to
    # ensure Istio control plane components are gradually upgraded or recovered.
    defaultPodDisruptionBudget:
      enabled: true
      # The values aren't mutable due to a current PodDisruptionBudget limitation

The ambient CNI agent is the only place where ambient network config and pod redirection machinery happens.

	overrideHelpStr = `If true, allow revision tags to be overwritten, otherwise reject revision tag updates that
overwrite existing revision tags.`
	revisionHelpStr = "Control plane revision to reference from a given revision tag"
	tagCreatedStr   = `Revision tag %q created, referencing control plane revision %q. To enable injection using this
revision tag, use 'kubectl label namespace <NAMESPACE> istio.io/rev=%s'
`

  // can have their pods stopped for an update at any given time. The update
  // starts by stopping at most 30% of those DaemonSet pods and then brings
  // up new DaemonSet pods in their place. Once the new pods are available,
  // it then proceeds onto other DaemonSet pods, thus ensuring that at least
  // 70% of original number of DaemonSet pods are available at all times during
  // the update.
  // +optional

		var icpTag string
		// create normalized tags for multiple control plane revisions
		for _, icp := range *icps {
			if icp.Revision != revision {
				continue
			}
			tagVer, err := GetTagVersion(icp.Info.GitTag)
			if err != nil {
				return err
			}
			icpTags = append(icpTags, tagVer)
		}
		// sort different versions of control plane revisions
		sort.Strings(icpTags)

    return 9
  fi
  # Workaround kind issue causing taints to not be removed in 1.24
  kubectl taint nodes "${NAME}"-control-plane node-role.kubernetes.io/control-plane- 2>/dev/null || true

  # Determine what CNI to install
  case "${KUBERNETES_CNI:-}" in 

    "calico")
      echo "Installing Calico CNI"
      install_calico "" "$(dirname "$CONFIG")"

* Be lightweight enough to not limit adoption.
  * This puts a much tighter budget on CPU, memory, latency, and throughput requirements than traditional Istio sidecars.

Ztunnel was not designed to be a feature-rich data plane.
Quite the opposite - an *aggressively* small feature set is the key feature that makes ztunnel viable.

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net"
	"net/url"
	"os"
	"strings"

	discovery "github.com/envoyproxy/go-control-plane/envoy/service/discovery/v3"
	xdsstatus "github.com/envoyproxy/go-control-plane/envoy/service/status/v3"
	"google.golang.org/grpc"
	v1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"istio.io/api/label"

three main components:

- [MeshConfig](https://github.com/istio/api/blob/master/mesh/v1alpha1/config.proto) for runtime config consumed directly by Istio
control plane components.
- [Component configuration API](https://github.com/istio/api/blob/00671adacbea20f941cb20cce021bc63cbad1840/operator/v1alpha1/operator.proto#L42-L93), for managing

	matcher "github.com/cncf/xds/go/xds/type/matcher/v3"
	listener "github.com/envoyproxy/go-control-plane/envoy/config/listener/v3"
	route "github.com/envoyproxy/go-control-plane/envoy/config/route/v3"
	hcm "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/network/http_connection_manager/v3"
	tcp "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/network/tcp_proxy/v3"
	"sigs.k8s.io/yaml"