# Istio CNI Node Agent

The Istio CNI Node Agent is responsible for several things

- Install an Istio CNI plugin binary on each node's filesystem, updating that node's CNI config in e.g (`/etc/cni/net.d`), and watching the config and binary paths to reinstall if things are modified.

  // an API request to apps/v1beta1 deployments would be converted and sent to the webhook
  // with `kind: {group:"apps", version:"v1", kind:"Deployment"}` (matching the rule the webhook registered for),
  // and `requestKind: {group:"apps", version:"v1beta1", kind:"Deployment"}` (indicating the kind of the original API request).
  //

tidy-docker:
	@docker image prune --all --force --filter="label=io.istio.repo=https://github.com/istio/tools" --filter="label!=io.istio.version=$(IMAGE_VERSION)"

# help works by looking over all Makefile includes matching `target: ## comment` regex and outputting them
help: ## Show this help
	@egrep -h '^[a-zA-Z_\.-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort  | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-20s\033[0m %s\n", $$1, $$2}'

  // More info: https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller/#what-is-a-replicationcontroller
  optional int32 replicas = 1;

  // The number of pods that have labels matching the labels of the pod template of the replicaset.
  // +optional
  optional int32 fullyLabeledReplicas = 2;

  // readyReplicas is the number of pods targeted by this ReplicaSet controller with a Ready Condition.

* It should not be client-specific.
  * In Istio sidecars, historically we had a lot of client-specific xDS. For example, putting the xDS-client's IP back into the xDS response. This makes efficient control plane implementation (most notably, caching), extremely challenging.
  * In practice, this largely means that references are fully qualified in the API. IP Addresses (generally) have a network associated with them, node names have a cluster associated with them, etc.

  // `resourceRules` is a slice of ResourcePolicyRules that identify matching requests according to their verb and the
  // target resource.
  // At least one of `resourceRules` and `nonResourceRules` has to be non-empty.
  // +listType=atomic
  // +optional
  repeated ResourcePolicyRule resourceRules = 2;

  // `nonResourceRules` is a list of NonResourcePolicyRules that identify matching requests according to their verb

  // `resourceRules` is a slice of ResourcePolicyRules that identify matching requests according to their verb and the
  // target resource.
  // At least one of `resourceRules` and `nonResourceRules` has to be non-empty.
  // +listType=atomic
  // +optional
  repeated ResourcePolicyRule resourceRules = 2;

  // `nonResourceRules` is a list of NonResourcePolicyRules that identify matching requests according to their verb

  // +optional
  optional string path = 1;

  // pathType determines the interpretation of the path matching. PathType can
  // be one of the following values:
  // * Exact: Matches the URL path exactly.
  // * Prefix: Matches based on a URL path prefix split by '/'. Matching is
  //   done on a path element by element basis. A path element refers is the

  // NamespaceSelector decides whether to run the webhook on an object based
  // on whether the namespace for that object matches the selector. If the
  // object itself is a namespace, the matching is performed on
  // object.metadata.labels. If the object is another cluster scoped resource,
  // it never skips the webhook.
  //
  // For example, to run the webhook on any objects whose namespace is not

  // +optional
  optional string path = 1;

  // pathType determines the interpretation of the path matching. PathType can
  // be one of the following values:
  // * Exact: Matches the URL path exactly.
  // * Prefix: Matches based on a URL path prefix split by '/'. Matching is
  //   done on a path element by element basis. A path element refers is the