`CmdAdd` is triggered when there is a new pod created. This runs on the node, in a chain of CNI plugins - Istio is
run after the main CNI sets up the pod IP and networking.

1. Check k8s pod namespace against exclusion list (plugin config)
    - Config must exclude namespace that Istio control-plane is installed in (TODO: this may change, exclude at pod level is sufficient and we may want Istiod and other istio components to use ambient too)

In the case of the sidecar injector, the namespace label `istio-env: <NAME_OF_ENV>` is used instead
of the conventional `istio-injected: true`. The name of the environment is defined as the namespace
where the corresponding control plane components (config, discovery, auto-injection) are running.
In the examples below, by default this is the `istio-control` namespace. Pod annotations can also
be used to select a different 'environment'.

This installs the controller into the cluster in the istio-operator namespace. The controller in turns installs
the Istio control plane into the istio-system namespace by default.

### Controller (running locally)

1. Set env $WATCH_NAMESPACE (default value is "istio-system") and $LEADER_ELECTION_NAMESPACE (default value is "istio-operator")

1. Create the `WATCH_NAMESPACE` and `LEADER_ELECTION_NAMESPACE` if they are not created yet.

```bash

To install the chart with the release name `istiod`:

```console
kubectl create namespace istio-system
helm install istiod istio/istiod --namespace istio-system
```

## Uninstalling the Chart

To uninstall/delete the `istiod` deployment:

```console
helm delete istiod --namespace istio-system
```

## Configuration

To view support configuration options and documentation, run:

Installation in `kube-system` is recommended to ensure the [`system-node-critical`](https://kubernetes.io/docs/tasks/administer-cluster/guaranteed-scheduling-critical-addon-pods/)
`priorityClassName` can be used. You can install in other namespace only on K8S clusters that allow
'system-node-critical' outside of kube-system.

## Configuration

To view support configuration options and documentation, run:

```console
helm show values istio/istio-cni
```

The script below can handle this for you. Replace `RELEASE` and `NAMESPACE` with the name and namespace of the release:

```console
KINDS=(service deployment)
RELEASE=istio-ingressgateway
NAMESPACE=istio-system
for KIND in "${KINDS[@]}"; do
    kubectl --namespace $NAMESPACE --overwrite=true annotate $KIND $RELEASE meta.helm.sh/release-name=$RELEASE

```

_See [helm repo](https://helm.sh/docs/helm/helm_repo/) for command documentation._

## Installing the Chart

To install the chart with the release name `istio-base`:

```console
kubectl create namespace istio-system
helm install istio-base istio/base -n istio-system
```

### Profiles

Istio Helm charts have a concept of a `profile`, which is a bundled collection of value presets.