canary deployments for Istio components. It should be possible to deploy a new version while keeping the
stable version in place and gradually migrate apps to the new version.

- More flexibility: the new installer allows multiple 'environments', allowing applications to select
a set of control plane settings and components. While the entire mesh respects the same APIs and config,

  // hostname of this endpoint. This field may be used by consumers of
  // endpoints to distinguish endpoints from each other (e.g. in DNS names).
  // Multiple endpoints which use the same hostname should be considered
  // fungible (e.g. multiple A values in DNS). Must be lowercase and pass DNS
  // Label (RFC 1123) validation.
  // +optional
  optional string hostname = 3;

  //
  // - In: the requirement is satisfied if at least one container exit code
  //   (might be multiple if there are multiple containers not restricted
  //   by the 'containerName' field) is in the set of specified values.
  // - NotIn: the requirement is satisfied if at least one container exit code
  //   (might be multiple if there are multiple containers not restricted
  //   by the 'containerName' field) is not in the set of specified values.

  // hostname of this endpoint. This field may be used by consumers of
  // endpoints to distinguish endpoints from each other (e.g. in DNS names).
  // Multiple endpoints which use the same hostname should be considered
  // fungible (e.g. multiple A values in DNS). Must be lowercase and pass DNS
  // Label (RFC 1123) validation.
  // +optional
  optional string hostname = 3;

Changes:
- separate namespace allows:
-- easier reconfig of just the gateway
-- TLS secrets and domain name management is isolated, for better security
-- simplified configuration
-- multiple versions of the ingress can be used, to minize upgrade risks

- the new chart uses the default namespace service account, and doesn't require
additional RBAC permissions.

- simplified label structure. Label change is not supported on upgrade.

  // Verb is a list of kubernetes resource API verbs, like: get, list, watch, create, update, delete, proxy.  "*" means all.
  repeated string verbs = 1;

  // APIGroups is the name of the APIGroup that contains the resources.  If multiple API groups are specified, any action requested against one of
  // the enumerated resources in any API group will be allowed.  "*" means all.
  // +optional
  repeated string apiGroups = 2;

### Inbound

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.

```yaml
meshConfig:
  accessLogFile: /dev/stdout
```

#### Revisions

Control plane revisions allow deploying multiple versions of the control plane in the same cluster.
This allows safe [canary upgrades](https://istio.io/latest/docs/setup/upgrade/canary/)

```yaml
revision: my-revision-name

  // Verbs is a list of Verbs that apply to ALL the ResourceKinds contained in this rule. '*' represents all verbs.
  repeated string verbs = 1;

  // APIGroups is the name of the APIGroup that contains the resources.  If multiple API groups are specified, any action requested against one of
  // the enumerated resources in any API group will be allowed. "" represents the core API group and "*" represents all API groups.
  // +optional

// that they have access to.
//
// It can be optionally associated with a particular assigner, in which case it
// contains one valid set of trust anchors for that signer. Signers may have
// multiple associated ClusterTrustBundles; each is an independent set of trust
// anchors for that signer. Admission control is used to enforce that only users
// with permissions on the signer can create or modify the corresponding bundle.