## Traffic routing

Based on the three [redirection](#redirection) paths, the ztunnel has three primary types of traffic it handles.

### Outbound

Requests leaving a pod go through the "outbound" code path on port 15001.
This is where most of Ztunnel's logic lives.

  // completedIndexes holds the completed indexes when .spec.completionMode =
  // "Indexed" in a text format. The indexes are represented as decimal integers
  // separated by commas. The numbers are listed in increasing order. Three or
  // more consecutive numbers are compressed and represented by the first and
  // last element of the series, separated by a hyphen.
  // For example, if the completed indexes are 1, 3, 4, 5 and 7, they are

## Introduction

The operator uses the [IstioOperator API](https://github.com/istio/api/blob/master/operator/v1alpha1/operator.proto), which has
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.

  // 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

// - StorageClass "standard" has "1234 GiB" available in "topology.kubernetes.io/zone=us-east1"
// - StorageClass "localssd" has "10 GiB" available in "kubernetes.io/hostname=knode-abc123"
//
// The following three cases all imply that no capacity is available for
// a certain combination:
// - no object exists with suitable topology and storage class name
// - such an object exists, but the capacity is unset

// - StorageClass "standard" has "1234 GiB" available in "topology.kubernetes.io/zone=us-east1"
// - StorageClass "localssd" has "10 GiB" available in "kubernetes.io/hostname=knode-abc123"
//
// The following three cases all imply that no capacity is available for
// a certain combination:
// - no object exists with suitable topology and storage class name
// - such an object exists, but the capacity is unset

//
// 	(Note that 1024 = 1Ki but 1000 = 1k; I didn't choose the capitalization.)
//
// <decimalExponent> ::= "e" <signedNumber> | "E" <signedNumber>
// ```
//
// No matter which of the three exponent forms is used, no quantity may represent
// a number greater than 2^63-1 in magnitude, nor may it have more than 3 decimal
// places. Numbers larger or more precise will be capped or rounded up.

// - StorageClass "standard" has "1234 GiB" available in "topology.kubernetes.io/zone=us-east1"
// - StorageClass "localssd" has "10 GiB" available in "kubernetes.io/hostname=knode-abc123"
//
// The following three cases all imply that no capacity is available for
// a certain combination:
// - no object exists with suitable topology and storage class name
// - such an object exists, but the capacity is unset

  // value automatically if one of them is empty and the other is non-empty.
  // When namespace is specified in dataSourceRef,
  // dataSource isn't set to the same value and must be empty.
  // There are three important differences between dataSource and dataSourceRef:
  // * While dataSource only allows two specific types of objects, dataSourceRef
  //   allows any non-core object, as well as PersistentVolumeClaim objects.