Istiod's primary role - and most code - is to dynamically configure proxies (Envoy sidecars and ingress, gRPC, ztunnel, and more). This roughly consists of 3 parts:
1. Config ingestion (inputs to the system)
1. Config translation
1. Config serving (XDS)

### Config Ingestion

    - 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`)
        - the file name can be explicitly set by `CNI_CONF_NAME` env var
        - the program inserts `CNI_NETWORK_CONFIG` into the `plugins` list in `/etc/cni/net.d/${CNI_CONF_NAME}`

format-python:
	@${FINDFILES} -name '*.py' -print0 | ${XARGS} autopep8 --max-line-length 160 --aggressive --aggressive -i

dump-licenses: mod-download-go
	@license-lint --config common/config/license-lint.yml --report

dump-licenses-csv: mod-download-go
	@license-lint --config common/config/license-lint.yml --csv

mirror-licenses: mod-download-go
	@rm -fr licenses
	@license-lint --mirror

TMP := $(shell mktemp -d -u)
UPDATE_BRANCH ?= "master"

If the change is a dynamic runtime configuration, it probably belongs in the [MeshConfig API](https://github.com/istio/api/blob/master/mesh/v1alpha1/config.proto).
This allows configuration without re-installing or restarting deployments.

If the change is to a Kubernetes field (such as modifying a Deployment attribute), it will likely need to be install-time configuration.

message DaemonSetUpdateStrategy {
  // Type of daemon set update. Can be "RollingUpdate" or "OnDelete". Default is RollingUpdate.
  // +optional
  optional string type = 1;

  // Rolling update config params. Present only if type = "RollingUpdate".
  // ---
  // TODO: Update this to follow our convention for oneOf, whatever we decide it
  // to be. Same as Deployment `strategy.rollingUpdate`.

- 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,
apps may target different 'environments' which contain different instances and variants of Istio.

- Better security: separate Istio components reside in different namespaces, allowing different teams or

CANONICAL_REVISION='latest'
CANONICAL_SERVICE='foo'
CA_ADDR='istiod-rev-1.istio-system.svc:15012'
CLUSTER_MESH_CONFIG_VALUE='foo'
ISTIO_INBOUND_PORTS='*'
ISTIO_LOCAL_EXCLUDE_PORTS='22,15090,15021,15020'
ISTIO_METAJSON_LABELS='{"service.istio.io/canonical-name":"foo","service.istio.io/canonical-revision":"latest"}'
ISTIO_META_CLUSTER_ID='Kubernetes'
ISTIO_META_DNS_CAPTURE='true'
ISTIO_META_MESH_ID=''
ISTIO_META_NETWORK=''
ISTIO_META_WORKLOAD_NAME='foo'

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.
- [Component configuration API](https://github.com/istio/api/blob/00671adacbea20f941cb20cce021bc63cbad1840/operator/v1alpha1/operator.proto#L42-L93), for managing

Ztunnel additionally will handle the rotation of these certificates (typically 24hr expiration) as they approach expiry.

## Telemetry

## PeerAuthentication and ztunnel