tests := []struct {
		desc     string
		domains  []string
		expected string
	}{
		{
			desc:     "test zero domain",
			domains:  []string{},
			expected: "",
		},
		{
			desc:     "test only one domain",
			domains:  []string{"example.com"},
			expected: "example.com",
		},
		{
			desc:     "test domains with port",
			domains:  []string{"example.com", "example.com:8080"},

ISTIO_META_NETWORK=''
ISTIO_META_WORKLOAD_NAME='foo'
ISTIO_NAMESPACE='bar'
ISTIO_SERVICE='foo.bar'
ISTIO_SERVICE_CIDR='*'
ISTIO_SVC_IP='10.10.10.10'
POD_NAMESPACE='bar'
SERVICE_ACCOUNT='vm-serviceaccount'

{{- define "mesh" }}
    # The trust domain corresponds to the trust root of a system.
    # Refer to https://github.com/spiffe/spiffe/blob/master/standards/SPIFFE-ID.md#21-trust-domain
    trustDomain: "cluster.local"

    # The namespace to treat as the administrative root namespace for Istio configuration.
    # When processing a leaf namespace Istio will search for declarations in that namespace first

    ISTIO_META_WORKLOAD_NAME: foo
    ISTIO_METAJSON_LABELS: '{"service.istio.io/canonical-name":"foo","service.istio.io/canonical-revision":"latest"}'
    POD_NAMESPACE: bar
    SERVICE_ACCOUNT: vm-serviceaccount
    TRUST_DOMAIN: ""
  readinessProbe:
    httpGet:

  {{- else }}
    image: "{{ .ProxyImage }}"
  {{- end }}
    ports:
    - containerPort: 15090
      protocol: TCP
      name: http-envoy-prom
    args:
    - proxy
    - router
    - --domain
    - $(POD_NAMESPACE).svc.{{ .Values.global.proxy.clusterDomain }}
    - --proxyLogLevel={{ annotation .ObjectMeta `sidecar.istio.io/logLevel` .Values.global.proxy.logLevel }}

ISTIO_META_WORKLOAD_NAME='foo'
ISTIO_NAMESPACE='bar'
ISTIO_SERVICE='foo.bar'
ISTIO_SERVICE_CIDR='*'
ISTIO_SVC_IP='fd00:10:96::1'
POD_NAMESPACE='bar'
PROXY_CONFIG_ANNOT_VALUE='bar'
SERVICE_ACCOUNT='vm-serviceaccount'

		"XDS Subject Alternative Name (for example istiod.istio-system.svc)")
	cmd.PersistentFlags().BoolVar(&o.InsecureSkipVerify, "insecure", viper.GetBool("INSECURE"),
		"Skip server certificate and domain verification. (NOT SECURE!)")
	cmd.PersistentFlags().BoolVar(&o.Plaintext, "plaintext", viper.GetBool("PLAINTEXT"),
		"Use plain-text HTTP/2 when connecting to server (no TLS).")
}

{{- define "mesh" }}
    # The trust domain corresponds to the trust root of a system.
    # Refer to https://github.com/spiffe/spiffe/blob/master/standards/SPIFFE-ID.md#21-trust-domain
    trustDomain: "cluster.local"

    # The namespace to treat as the administrative root namespace for Istio configuration.
    # When processing a leaf namespace Istio will search for declarations in that namespace first

			}
		}
	}
	return w.Flush()
}

func describeRouteDomains(domains []string) string {
	if len(domains) == 0 {
		return ""
	}
	if len(domains) == 1 {
		return domains[0]
	}

	// Return the shortest non-numeric domain.  Count of domains seems uninteresting.
	max := 2
	withoutPort := make([]string, 0, len(domains))
	for _, d := range domains {
		if !strings.Contains(d, ":") {

2. Copy any TLS certificate to the new namespace, and configure the domains.
3. Checking the new gateway work - for example by overriding the IP in /etc/hosts
4. Modify the DNS server to add the A record of the new namespace
5. Check traffic
6. Delete the A record corresponding to the gateway in istio-system
7. Upgrade istio-system, disabling the ingressgateway
8. Delete the domain TLS certs from istio-system.