[docs] Specify namespace when launching pulsar-manager

[matthewfollegot]

In the Get started in Kubernetes quickstart tutorial, one of the commands is insufficient and throws an error. I have proposed a solution to this by specifying the pulsar namespace to the command to fix the issue. There is no associated issue that I created as the work and fix is rather trivial.

Modifications

• added the namespace to the command minikube service pulsar-mini-pulsar-manager in step 4 of Get started in Kubernetes

Sample output of minikube service list:

|----------------------|----------------------------|--------------|---------------------------|
|      NAMESPACE       |            NAME            | TARGET PORT  |            URL            |
|----------------------|----------------------------|--------------|---------------------------|
| default              | kubernetes                 | No node port |
| kube-system          | kube-dns                   | No node port |
| kubernetes-dashboard | dashboard-metrics-scraper  | No node port |
| kubernetes-dashboard | kubernetes-dashboard       | No node port |
| pulsar               | pulsar-mini-bookie         | No node port |
| pulsar               | pulsar-mini-broker         | No node port |
| pulsar               | pulsar-mini-grafana        | server/3000  | http://192.168.64.2:31042 |
| pulsar               | pulsar-mini-prometheus     | No node port |
| pulsar               | pulsar-mini-proxy          | http/80      | http://192.168.64.2:31019 |
|                      |                            | pulsar/6650  | http://192.168.64.2:31621 |
| pulsar               | pulsar-mini-pulsar-manager | server/9527  | http://192.168.64.2:32267 |
| pulsar               | pulsar-mini-toolset        | No node port |
| pulsar               | pulsar-mini-zookeeper      | No node port |
|----------------------|----------------------------|--------------|---------------------------|

Thus, minikube service pulsar pulsar-mini-pulsar-manager is an insufficient command, it returns

💣  Service 'pulsar-mini-pulsar-manager' was not found in 'default' namespace.
You may select another namespace by using 'minikube service pulsar-mini-pulsar-manager -n <namespace>'. Or list out all the services using 'minikube service list'

By changing the command to minikube service -n pulsar pulsar-mini-pulsar-manager this specifies the correct namespace and results in the Pulsar Manager UI being opened in the default browser.

Verifying this change

• Make sure that the change passes the CI checks.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API: no
• The schema: no
• The default values of configurations: no
• The wire protocol: no
• The rest endpoints: no
• The admin cli options: no
• Anything that affects deployment: no

Documentation

• Does this pull request introduce a new feature? no