fix the egress gateway example for multi cluster gateways (#4397)

* fix the egress gateway example

need to change static because one address was host the other was ip.

* update to make it cleaner

* minor typo

* minor tweaks

* fix lint

* format change

* fix lint

* fix lint

* clean up tips per frank and shriram's suggestion

* fix lint

content/docs/tasks/multicluster/gateways/index.md

@@ -139,14 +139,61 @@ running in a second cluster.
 
 ## Send remote cluster traffic using egress gateway
 
-If you want to route traffic from `cluster1` via a dedicated
-egress gateway, instead of directly from the sidecars,
+If you want to route traffic from `cluster1` via a dedicated egress gateway, instead of directly from the sidecars,
 use the following service entry for `httpbin.bar` instead of the one in the previous section.
 
 {{< tip >}}
 The egress gateway used in this configuration cannot also be used for other, non inter-cluster, egress traffic.
 {{< /tip >}}
 
+If `$CLUSTER2_GW_ADDR` is an IP address, use the `$CLUSTER2_GW_ADDR - IP address` option.  If `$CLUSTER2_GW_ADDR` is a hostname, use the `$CLUSTER2_GW_ADDR - hostname` option.
+
+{{< tabset cookie-name="profile" >}}
+
+{{< tab name="$CLUSTER2_GW_ADDR - IP address" cookie-value="option1" >}}
+* Export the `cluster1` egress gateway address:
+
+{{< text bash >}}
+$ export CLUSTER1_EGW_ADDR=$(kubectl get --context=$CTX_CLUSTER1 svc --selector=app=istio-egressgateway \
+    -n istio-system -o yaml -o jsonpath='{.items[0].spec.clusterIP}')
+{{< /text >}}
+
+* Apply the httpbin-bar service entry:
+
+{{< text bash >}}
+$ kubectl apply --context=$CTX_CLUSTER1 -n foo -f - <<EOF
+apiVersion: networking.istio.io/v1alpha3
+kind: ServiceEntry
+metadata:
+  name: httpbin-bar
+spec:
+  hosts:
+  # must be of form name.namespace.global
+  - httpbin.bar.global
+  location: MESH_INTERNAL
+  ports:
+  - name: http1
+    number: 8000
+    protocol: http
+  resolution: STATIC
+  addresses:
+  - 127.255.0.2
+  endpoints:
+  - address: ${CLUSTER2_GW_ADDR}
+    network: external
+    ports:
+      http1: 15443 # Do not change this port value
+  - address: ${CLUSTER1_EGW_ADDR}
+    ports:
+      http1: 15443
+EOF
+{{< /text >}}
+
+{{< /tab >}}
+
+{{< tab name="$CLUSTER2_GW_ADDR - hostname" cookie-value="option2" >}}
+If the `${CLUSTER2_GW_ADDR}` is a hostname, you can use `resolution: DNS` for the endpoint resolution:
+
 {{< text bash >}}
 $ kubectl apply --context=$CTX_CLUSTER1 -n foo -f - <<EOF
 apiVersion: networking.istio.io/v1alpha3
@@ -176,6 +223,10 @@ spec:
 EOF
 {{< /text >}}
 
+{{< /tab >}}
+
+{{< /tabset >}}
+
 ## Version-aware routing to remote services
 
 If the remote service has multiple versions, you can add