Deploying a Sample Application

In this module we will deploy a sample application running a webservice on the Windows Node. This application will be running inside a Windows Container on the Windows Node.

Deploy the Application

Now, back on the bastion host, you will deploy the application in a new namespace called windows-workloads.

First create the namespace

oc new-project windows-workloads

Next, deploy the sample application.

oc create -n windows-workloads -f \
https://gist.githubusercontent.com/suhanime/683ee7b5a2f55c11e3a26a4223170582/raw/d893db98944bf615fccfe73e6e4fb19549a362a5/WinWebServer.yaml

Once deployed you can explore everything that’s been created

Explore Artifacts

The application should have deployed as a pod

oc get pods -n windows-workloads

NAME                             READY   STATUS    RESTARTS   AGE
win-webserver-549cd7495d-f6j95   1/1     Running   0          5m58s

This pod was created by a deployment. Remember to note that it has a toleration so it can run on the Windows Node.

oc get deploy win-webserver -n windows-workloads -o jsonpath='{.spec.template.spec.tolerations}' | jq -r

If you take a look at the pod, you see that it’s running on the Windows Node.

oc get pods -n windows-workloads -o wide

NAME                             READY   STATUS    RESTARTS   AGE    IP           NODE                         NOMINATED NODE   READINESS GATES
win-webserver-549cd7495d-k7zqt   1/1     Running   0          100s   10.132.1.2   ip-10-0-138-9.ec2.internal   <none>           <none>

oc get nodes -l kubernetes.io/os=windows

NAME                         STATUS   ROLES    AGE   VERSION
ip-10-0-138-9.ec2.internal   Ready    worker   22m   v1.21.1-1398+98073871f173ba

oc -n openshift-windows-machine-config-operator rsh deploy/winc-ssh

Then using the provided shellscript to login to the Windows Node via nodename

sh-4.4$ sshcmd.sh ip-10-0-138-9.ec2.internal

To view Windows containers running on the node, you need to install the crictl tool to interact with the containerd runtime.

$ProgressPreference = "SilentlyContinue"; wget https://github.com/kubernetes-sigs/cri-tools/releases/download/v1.27.0/crictl-v1.27.0-windows-amd64.tar.gz -o crictl-v1.27.0-windows-amd64.tar.gz; tar -xvf crictl-v1.27.0-windows-amd64.tar.gz -C C:\Windows\

Now lets configure crictl.

crictl config --set runtime-endpoint="npipe:\\\\.\\pipe\\containerd-containerd"

Here, you can see the Windows container running on the node.

crictl ps

Here you’ll see the Container running. Here is an example output.

CONTAINER           IMAGE               CREATED             STATE               NAME                ATTEMPT             POD ID              POD
ac18c2aa692cf       66a1a48cbc112       2 minutes ago       Running             windowswebserver    0                   a2f1b580c659c       win-webserver-7b76494c5-s9m2q

You can also see the images downloaded on the host.

crictl images

You should see the following output.

IMAGE                                    TAG                 IMAGE ID            SIZE
mcr.microsoft.com/oss/kubernetes/pause   3.6                 9adbbe02501b1       104MB
mcr.microsoft.com/windows/servercore     ltsc2019            66a1a48cbc112       2.02GB

Exit out of the Windows Node.

PS C:\Users\Administrator> exit

Also exit from the rsh session.

sh-4.4$ exit
exit
[ec2-user@bastion ~]$

You can create a route just like any other workload.

oc expose svc/win-webserver -n windows-workloads

You can now access it via the route.

curl -s http://$(oc get route win-webserver -n windows-workloads -o jsonpath='{.spec.host}')

<html><body><H1>Windows Container Web Server</H1></body></html>

You can rsh into this pod just like a Linux pod by using oc exec. The following command will get you a PowerShell prompt in the Windows Webserver pod.

oc -n windows-workloads exec -it deploy/win-webserver -- powershell

Once inside, you can see the process that’s running the webserver.

PS C:\> tasklist /M /FI "IMAGENAME eq powershell.exe"  | Select-String -Pattern http

Exit out of the exec session before continuing.

PS C:\> exit