Traffic entering a pod over HBONE will be handled by the "inbound" code path, on port 15008.

Incoming requests have multiple "layers": TLS wrapping HTTP CONNECT that is wrapping the user's connection.

To unwrap the first layer, we terminate TLS.
As part of this, we need to pick the correct certificate to serve on behalf of the destination workload.
As discussed in [HBONE](#hbone), this is based on the destination IP.

- `install-cni` container
    - copies `istio-cni` and `istio-iptables` to `/opt/cni/bin`
    - creates kubeconfig for the service account the pod runs under
    - periodically copy the K8S JWT token for istio-cni on the host to connect to K8S.
    - injects the CNI plugin config to the CNI config file
        - CNI installer will try to look for the config file under the mounted CNI net dir based on file name extensions (`.conf`, `.conflist`)

//
// Kubelets use this API to obtain:
//  1. client certificates to authenticate to kube-apiserver (with the "kubernetes.io/kube-apiserver-client-kubelet" signerName).
//  2. serving certificates for TLS endpoints kube-apiserver can connect to securely (with the "kubernetes.io/kubelet-serving" signerName).
//
// This API can be used to request client certificates to authenticate to kube-apiserver
// (with the "kubernetes.io/kube-apiserver-client" signerName),

// sure that all the tuple expansions are valid.
message RuleWithOperations {
  // Operations is the operations the admission hook cares about - CREATE, UPDATE, DELETE, CONNECT or *
  // for all of those operations and any future admission operations that are added.
  // If '*' is present, the length of the slice must be one.
  // Required.
  // +listType=atomic

At a high level, each client job will find the correct generator for the request, generate the required configuration, and send it.

#### Optimizations

A naive implementation would simply regenerate all resources, of all subscribed types, for each client, on any configuration change. However, this scales poorly. As a result, we have many levels of optimizations to avoid doing this work.