add a step to confirm that Bookinfo is running without ingress (#3125)

* add a step to confirm that Bookinfo is running without ingress

to verify that the app with Istio runs correctly without ingress,
to separate Istio installation errors from Ingress configuration
errors, to prevent questions like these
https://stackoverflow.com/questions/54307216/istio-proxy-unable-to-connect-to-istio-pilot

* fix the links to the renamed section (confirm the app is accessible...)

content/blog/2018/egress-https/index.md

@@ -44,7 +44,7 @@ Here is a copy of the end-to-end architecture of the application from the origin
 
 Perform the steps in the
 [Deploying the application](/docs/examples/bookinfo/#deploying-the-application),
-[Confirm the app is running](/docs/examples/bookinfo/#confirm-the-app-is-running), and
+[Confirm the app is running](/docs/examples/bookinfo/#confirm-the-app-is-accessible-from-outside-the-cluster), and
 [Apply default destination rules](/docs/examples/bookinfo/#apply-default-destination-rules)
 sections.
 

content/docs/examples/bookinfo/index.md

@@ -123,6 +123,14 @@ To start the application, follow the instructions corresponding to your Istio ru
     reviews-v3-1813607990-8ch52                 2/2       Running   0          6m
     {{< /text >}}
 
+1.  To confirm that the Bookinfo application is running, send a request to it by a `curl` command from some pod, for
+    example from `ratings`:
+
+    {{< text bash >}}
+    $ kubectl exec -it $(kubectl get pod -l app=ratings -o jsonpath='{.items[0].metadata.name}') -c ratings -- curl productpage:9080/productpage | grep -o "<title>.*</title>"
+    <title>Simple Bookstore App</title>
+    {{< /text >}}
+
 #### Determining the ingress IP and port
 
 Now that the Bookinfo services are up and running, you need to make the application accessible from outside of your
@@ -151,7 +159,7 @@ is used for this purpose.
     $ export GATEWAY_URL=$INGRESS_HOST:$INGRESS_PORT
     {{< /text >}}
 
-1.  Proceed to [Confirm the app is running](#confirm-the-app-is-running), below.
+1.  Proceed to [Confirm the app is running](#confirm-the-app-is-accessible-from-outside-the-cluster), below.
 
 ### If you are running on Docker with Consul
 
@@ -186,9 +194,9 @@ is used for this purpose.
     For example, replace `samples/bookinfo/networking/destination-rule-all.yaml` with
     `samples/bookinfo/platform/consul/destination-rule-all.yaml` in the `kubectl apply` command, below.
 
-## Confirm the app is running
+## Confirm the app is accessible from outside the cluster
 
-To confirm that the Bookinfo application is running, run the following `curl` command:
+To confirm that the Bookinfo application is accessible from outside the cluster, run the following `curl` command:
 
 {{< text bash >}}
 $ curl http://${GATEWAY_URL}/productpage | grep -o "<title>.*</title>"