- Configures required iptables, sockets, and packet routing miscellanea within the `ztunnel` and application pod network namespaces to make that happen.

This component accomplishes that in the following ways:

1. By installing a separate, very basic "CNI plugin" binary onto the node to forward low-level pod lifecycle events (CmdAdd/CmdDel/etc) from whatever node-level CNI subsystem is in use to this node agent for processing via socket.

     explicitly and finally terminates Your grants, and (b) on an ongoing
     basis, if such Contributor fails to notify You of the non-compliance by
     some reasonable means prior to 60 days after You have come back into
     compliance. Moreover, Your grants from a particular Contributor are
     reinstated on an ongoing basis if such Contributor notifies You of the

The ztunnel is primarily a mechanism to get traffic to the waypoints, securely.

## Proxy implementation

In its initial implementations, the ztunnel was actually implemented in 3 different ways: a bespoke Rust implementation, a bespoke Go implementation, and in Envoy.

     explicitly and finally terminates Your grants, and (b) on an ongoing basis,
     if such Contributor fails to notify You of the non-compliance by some
     reasonable means prior to 60 days after You have come back into compliance.
     Moreover, Your grants from a particular Contributor are reinstated on an
     ongoing basis if such Contributor notifies You of the non-compliance by

     explicitly and finally terminates Your grants, and (b) on an ongoing basis,
     if such Contributor fails to notify You of the non-compliance by some
     reasonable means prior to 60 days after You have come back into compliance.
     Moreover, Your grants from a particular Contributor are reinstated on an
     ongoing basis if such Contributor notifies You of the non-compliance by

  // Required.
  optional string name = 2;
}

// Subject matches the originator of a request, as identified by the request authentication system. There are three
// ways of matching an originator; by user, group, or service account.
// +union
message Subject {
  // `kind` indicates which one of the other fields is non-empty.
  // Required
  // +unionDiscriminator

  // Required.
  optional string name = 2;
}

// Subject matches the originator of a request, as identified by the request authentication system. There are three
// ways of matching an originator; by user, group, or service account.
// +union
message Subject {
  // `kind` indicates which one of the other fields is non-empty.
  // Required
  // +unionDiscriminator

      # For example:
      # podAntiAffinityLabelSelector:
      # - key: security
      #   operator: In
      #   values: S1,S2
      #   topologyKey: "kubernetes.io/hostname"
      # This pod anti-affinity rule says that the pod requires not to be scheduled
      # onto a node if that node is already running a pod with label having key
      # "security" and value "S1".
      podAntiAffinityLabelSelector: []

      # For example:
      # podAntiAffinityLabelSelector:
      # - key: security
      #   operator: In
      #   values: S1,S2
      #   topologyKey: "kubernetes.io/hostname"
      # This pod anti-affinity rule says that the pod requires not to be scheduled
      # onto a node if that node is already running a pod with label having key
      # "security" and value "S1".
      podAntiAffinityLabelSelector: []

// limitations under the License.

package nodeagent

import (
	"context"
	"errors"
	"fmt"
	"io"
	"net"
	"os"
	"sync"
	"time"

	"golang.org/x/sys/unix"
	"google.golang.org/protobuf/proto"
	v1 "k8s.io/api/core/v1"

	"istio.io/istio/pkg/monitoring"
	"istio.io/istio/pkg/spiffe"
	"istio.io/istio/pkg/zdsapi"
)

var (