Use Kubernetes on Windows Server nodes¶
Observe the following prerequisites prior to using Kubernetes on Windows Server nodes.
Install MKE.
Note
Running Kubernetes on Windows Server nodes is only supported on MKE 3.3.0 and later. If you want to run Kubernetes on Windows Server nodes on a cluster that is currently running an earlier version of MKE than 3.3.0, you must perform a fresh install of MKE 3.3.0 or later.
Add Windows Server nodes¶
Log in to the MKE web UI.
In the left-side navigation panel, navigate to Shared Resources > Nodes and click Add Node.
Under NODE TYPE, select Windows. Windows Server nodes can only be workers.
Optional. Specify custom listen and advertise addresses by using the relevant slider.
Copy the command generated at the bottom of the Add Node page, which includes the
join-token
.Example command:
docker swarm join \ --token SWMTKN-1-2is7c14ff43tq1g61ubc5egvisgilh6m8qxm6dndjzgov9qjme-4388n8bpyqivzudz4fidqm7ey \ 172.31.2.154:2377
Add your Windows Server node to the MKE cluster by running the docker swarm join command copied in the previous step.
Validate your cluster¶
To validate your cluster using the MKE web UI:
Log in to the MKE web UI.
In the left-side navigation panel, navigate to Nodes. A green circle indicates a healthy node state. All nodes should be green.
Change each node orchestrator to Kubernetes:
Click on the node.
In the upper-right corner, click the gear icon.
In the Role section of the Details tab, select Kubernetes under ORCHESTRATOR TYPE.
Click Save.
Repeat the above steps for each node.
To validate your cluster using the command line:
View the status of all the nodes in your cluster:
kubectl get nodes
Your nodes should all have a status value of
Ready
, as in the following example:NAME STATUS ROLES AGE VERSION user-135716-win-0 Ready <none> 2m16s v1.17.2 user-7d985f-ubuntu-0 Ready master 4m55s v1.17.2-docker-d-2 user-135716-win-1 Ready <none> 1m12s v1.17.2
Change each node orchestrator to Kubernetes:
docker node update <node name> --label-add com.docker.ucp.orchestrator.kubernetes=true
Repeat the last step for each node.
Deploy a workload on your cluster to verify that everything works as expected.
Troubleshoot¶
If you cannot join your Windows Server node to the cluster, confirm that the correct processes are running on the node.
Verify that the
tigera-calico
process is operational:PS C:\> Get-Process tigera-calico
Example output:
Handles NPM(K) PM(K) WS(K) CPU(s) Id SI ProcessName ------- ------ ----- ----- ------ -- -- ----------- 276 17 33284 40948 39.89 8132 0 tigera-calico
Verify that the
kubelet
process is operational:PS C:\> Get-Process kubelet
Example output:
Handles NPM(K) PM(K) WS(K) CPU(s) Id SI ProcessName ------- ------ ----- ----- ------ -- -- ----------- 524 23 47332 73380 828.50 6520 0 kubelet
Verify that the
kube-proxy
process is operational:PS C:\> Get-Process kube-proxy Example output:
Handles NPM(K) PM(K) WS(K) CPU(s) Id SI ProcessName ------- ------ ----- ----- ------ -- -- ----------- 322 19 25464 33488 21.00 7852 0 kube-proxy
If any of the process verifications indicate that something is not working, review the logs. The
tigera-calico
logs are located underC:\TigeraCalico\logs
and thekubelet
andkube-proxy
logs are located underC:\k\logs
.
Deploy a workload on Windows Server¶
The following procedure deploys a complete web application on IIS servers as Kubernetes Services. The example workload includes an MSSQL database and a load balancer. The procedure includes the following tasks:
Namespace creation
Pod and deployment scheduling
Kubernetes Service provisioning
Application workload deployment
Pod, Node, and Service configuration
Create a namespace:
kubectl create -f demo-namespace.yaml
File created:
apiVersion: v1 kind: Namespace metadata: name: demo
Create a web service as a Kubernetes Service:
kubectl create -f win-webserver.yaml
Expected output:
service/win-webserver created deployment.apps/win-webserver created
Verify creation of the Kubernetes Service:
kubectl get service --namespace demo
Expected output:
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE win-webserver NodePort 10.96.29.12 <none> 80:35048/TCP 12m
File created:
apiVersion: v1 kind: Service metadata: name: win-webserver labels: app: win-webserver namespace: demo spec: ports: - port: 80 targetPort: 80 selector: app: win-webserver type: NodePort --- apiVersion: apps/v1 kind: Deployment metadata: labels: app: win-webserver name: win-webserver namespace: demo spec: replicas: 2 selector: matchLabels: app: win-webserver template: metadata: labels: app: win-webserver name: win-webserver spec: affinity: podAntiAffinity: requiredDuringSchedulingIgnoredDuringExecution: - labelSelector: matchExpressions: - key: app operator: In values: - win-webserver topologyKey: "kubernetes.io/hostname" containers: - name: windowswebserver image: mcr.microsoft.com/windows/servercore:ltsc2019 command: - powershell.exe - -command - "<#code used from https://gist.github.com/wagnerandrade/5424431#> ; $$listener = New-Object System.Net.HttpListener ; $$listener.Prefixes.Add('http://*:80/') ; $$listener.Start() ; $$callerCounts = @{} ; Write-Host('Listening at http://*:80/') ; while ($$listener.IsListening) { ;$$context = $$listener.GetContext() ;$$requestUrl = $$context.Request.Url ;$$clientIP = $$context.Request.RemoteEndPoint.Address ;$$response = $$context.Response ;Write-Host '' ;Write-Host('> {0}' -f $$requestUrl) ; ;$$count = 1 ;$$k=$$callerCounts.Get_Item($$clientIP) ;if ($$k -ne $$null) { $$count += $$k } ;$$callerCounts.Set_Item($$clientIP, $$count) ;$$ip=(Get-NetAdapter | Get-NetIpAddress); $$header='<html><body><H1>Windows Container Web Server</H1>' ;$$callerCountsString='' ;$$callerCounts.Keys | % { $$callerCountsString+='<p>IP {0} callerCount {1} ' -f $$ip[1].IPAddress,$$callerCounts.Item($$_) } ;$$footer='</body></html>' ;$$content='{0}{1}{2}' -f $$header,$$callerCountsString,$$footer ;Write-Output $$content ;$$buffer = [System.Text.Encoding]::UTF8.GetBytes($$content) ;$$response.ContentLength64 = $$buffer.Length ;$$response.OutputStream.Write($$buffer, 0, $$buffer.Length) ;$$response.Close() ;$$responseStatus = $$response.StatusCode ;Write-Host('< {0}' -f $$responseStatus) } ; " nodeSelector: beta.kubernetes.io/os: windows
Review the pods deployed on your Windows Server worker nodes with inter-pod affinity and anti-affinity.
Note
After creating the web service, it may take several minutes for the pods to enter a ready state.
kubectl get pod --namespace demo
Expected output:
NAME READY STATUS RESTARTS AGE win-webserver-8c5678c68-qggzh 1/1 Running 0 6m21s win-webserver-8c5678c68-v8p84 1/1 Running 0 6m21s
Review the detailed status of pods deployed:
kubectl describe pod win-webserver-8c5678c68-qggzh --namespace demo
From a kubectl client, access the web service using node-to-pod communication across the network:
kubectl get pods --namespace demo -o wide
Example output:
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES win-webserver-8c5678c68-qggzh 1/1 Running 0 16m 192.168.77.68 user-135716-win-1 <none> <none> win-webserver-8c5678c68-v8p84 1/1 Running 0 16m 192.168.4.206 user-135716-win-0 <none> <none>
SSH into the master node:
ssh -o ServerAliveInterval=15 root@<master-node>
Use
curl
to access the web service:curl 10.96.29.12
Example output:
<html><body><H1>Windows Container Web Server</H1><p>IP 192.168.77.68 callerCount 1 </body></html>
Run the
curl
command a second time. You can see the second request load-balanced to a different pod:curl 10.96.29.12
Example output:
<html><body><H1>Windows Container Web Server</H1><p>IP 192.168.4.206 callerCount 1 </body></html>
From a kubectl client, access the web service using pod-to-pod communication across the network:
kubectl get service --namespace demo
Expample output:
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE win-webserver NodePort 10.96.29.12 <none> 80:35048/TCP 12m
Review the pod status:
kubectl get pods --namespace demo -o wide
Example output:
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES win-webserver-8c5678c68-qggzh 1/1 Running 0 16m 192.168.77.68 user-135716-win-1 <none> <none> win-webserver-8c5678c68-v8p84 1/1 Running 0 16m 192.168.4.206 user-135716-win-0 <none> <none>
Exec into the web service:
kubectl exec -it win-webserver-8c5678c68-qggzh --namespace demo cmd
Example output:
Microsoft Windows [Version 10.0.17763.1098] (c) 2018 Microsoft Corporation. All rights reserved.
Use
curl
to access the web service:C:\>curl 10.96.29.12
Example output:
<html><body><H1>Windows Container Web Server</H1><p>IP 192.168.77.68 callerCount 1 <p>IP 192.168.77.68 callerCount 1 </body></html>