Lab 1. Set up and deploy your first application

1. Deploy the guestbook application

In this part of the lab we will deploy an application called guestbook that has already been built and uploaded to DockerHub under the name ibmcom/guestbook:v1.

1. If your current project is the default project, create a new project

   oc new-project my-guestbook

2. Start by running guestbook:

   oc create deployment guestbook --image=ibmcom/guestbook:v1

   This action will take a bit of time. To check the status of the running application, you can use $ oc get pods.

   You should see output similar to the following:

   oc get pods

   Eventually, the status should show up as Running.

   $ oc get pods
   NAME                          READY     STATUS              RESTARTS   AGE
   guestbook-59bd679fdc-bxdg7    1/1       Running             0          1m

   The end result of the run command is not just the pod containing our application containers, but a Deployment resource that manages the lifecycle of those pods.

3. Once the status reads Running, we need to expose that deployment as a service so we can access it through the IP of the worker nodes. The guestbook application listens on port 3000. Run:

   oc expose deployment guestbook --type="NodePort" --port=3000

4. To find the port used on that worker node, examine your new service:

   $ oc get service guestbook
   NAME        TYPE       CLUSTER-IP     EXTERNAL-IP   PORT(S)          AGE
   guestbook   NodePort   10.10.10.253   <none>        3000:31208/TCP   1m

   We can see that our <nodeport> is 31208. We can see in the output the port mapping from 3000 inside the pod exposed to the cluster on port 31208. This port in the 31000 range is automatically chosen, and could be different for you.

5. guestbook is now running on your cluster, and exposed to the internet. We need to find out where it is accessible. The worker nodes running in the container service get external IP addresses.

   Get the workers for your cluster and note one (any one) of the public IPs listed in the <EXTERNAL-IP> column.

   $ oc get nodes -o wide
   NAME            STATUS   ROLES           AGE   VERSION           INTERNAL-IP     EXTERNAL-IP      OS-IMAGE   KERNEL-VERSION                CONTAINER-RUNTIME
   10.189.80.112   Ready    master,worker   10d   v1.16.2+283af84   10.189.80.112   169.60.111.167   Red Hat    3.10.0-1127.13.1.el7.x86_64   cri-o://1.16.6-17.rhaos4.3.git4936f44.el7
   10.189.80.113   Ready    master,worker   10d   v1.16.2+283af84   10.189.80.113   169.60.111.164   Red Hat    3.10.0-1127.13.1.el7.x86_64   cri-o://1.16.6-17.rhaos4.3.git4936f44.el7

6. Now that you have both the address and the port, you can now access the application in the web browser at <EXTERNAL-IP>:<nodeport>. In the example case this is 169.60.111.167:31208.

Congratulations, you've now deployed an application to Kubernetes!

When you're all done, continue to the next lab of this course.