following the guidance below.
If you are able to, a clean installation is simpler. However, this often requires an external IP migration which can be challenging.

WARNING: when installing over an existing deployment, the two deployments will be merged together by Helm, which may lead to unexpected results.

#### Legacy Gateway Helm charts

`).ApplyOrFail(t)

			// create a new istiod pod using the template from the deployment, but not managed by the deployment
			t.Logf("creating pod %s/%s", ns, pod)
			deps, err := primary.Kube().AppsV1().
				Deployments(ns).List(context.TODO(), metav1.ListOptions{LabelSelector: "app=istiod"})
			if err != nil {
				t.Fatal(err)
			}
			if len(deps.Items) == 0 {
				t.Skip("no deployments with label app=istiod")
			}

          value: REDIRECT
        - name: ISTIO_META_WORKLOAD_NAME
          value: istio-ingressgateway
        - name: ISTIO_META_OWNER
          value: kubernetes://apis/apps/v1/namespaces/default/deployments/istio-ingressgateway
        - name: ISTIO_META_MESH_ID
          value: cluster.local
        - name: TRUST_DOMAIN
          value: cluster.local
        image: gcr.io/istio-testing/proxyv2:latest

# See the License for the specific language governing permissions and
# limitations under the License.

WD=$(dirname "$0")
WD=$(cd "$WD"; pwd)

set -eux

# This script sets up the plain text rendered deployments for addons
# See samples/addons/README.md for more information

ADDONS="${WD}/../../samples/addons"
DASHBOARDS="${WD}/dashboards"
mkdir -p "${ADDONS}"
TMP=$(mktemp -d)
LOKI_VERSION=${LOKI_VERSION:-"6.6.3"}

            fieldRef:
              fieldPath: spec.nodeName
        - name: ISTIO_META_WORKLOAD_NAME
          value: grpc
        - name: ISTIO_META_OWNER
          value: kubernetes://apis/apps/v1/namespaces/default/deployments/grpc
        - name: ISTIO_META_MESH_ID
          value: cluster.local
        - name: TRUST_DOMAIN
          value: cluster.local
        - name: ISTIO_META_DNS_CAPTURE
          value: "false"

          value: REDIRECT
        - name: ISTIO_META_WORKLOAD_NAME
          value: traffic
        - name: ISTIO_META_OWNER
          value: kubernetes://apis/apps/v1/namespaces/default/deployments/traffic
        - name: ISTIO_META_MESH_ID
          value: cluster.local
        - name: TRUST_DOMAIN
          value: cluster.local
        image: gcr.io/istio-testing/proxyv2:latest
        name: istio-proxy

          value: REDIRECT
        - name: ISTIO_META_WORKLOAD_NAME
          value: hello
        - name: ISTIO_META_OWNER
          value: kubernetes://apis/apps/v1/namespaces/default/deployments/hello
        - name: ISTIO_META_MESH_ID
          value: cluster.local
        - name: TRUST_DOMAIN
          value: cluster.local
        image: foo/bar
        name: istio-proxy
        ports:

          value: REDIRECT
        - name: ISTIO_META_WORKLOAD_NAME
          value: hello
        - name: ISTIO_META_OWNER
          value: kubernetes://apis/apps/v1/namespaces/default/deployments/hello
        - name: ISTIO_META_MESH_ID
          value: cluster.local
        - name: TRUST_DOMAIN
          value: cluster.local
        image: gcr.io/istio-testing/proxyv2:latest
        name: istio-proxy

          value: REDIRECT
        - name: ISTIO_META_WORKLOAD_NAME
          value: hello
        - name: ISTIO_META_OWNER
          value: kubernetes://apis/apps/v1/namespaces/default/deployments/hello
        - name: ISTIO_META_MESH_ID
          value: cluster.local
        - name: TRUST_DOMAIN
          value: cluster.local
        image: gcr.io/istio-testing/proxyv2:latest
        name: istio-proxy

          value: REDIRECT
        - name: ISTIO_META_WORKLOAD_NAME
          value: hello
        - name: ISTIO_META_OWNER
          value: kubernetes://apis/apps/v1/namespaces/default/deployments/hello
        - name: ISTIO_META_MESH_ID
          value: cluster.local
        - name: TRUST_DOMAIN
          value: cluster.local
        image: gcr.io/istio-testing/proxyv2:latest
        name: istio-proxy