Blog & Insights

By Brad Johnson, Lead DevOps Engineer

Continuing from 'Creating an OpenShift Cluster in AWS with Windows Worker Nodes (Part I)', we are going to install OpenShift Cluster in this section. We are going to use a public Route53 domain name for our install.

If you wish to create a private cluster then you will need to do a bit more setup. See the following pages for more information on creating a private cluster that does not require DNS. The first page has the RedHat solution on the install-config program not supporting private clusters and contains an install config yaml file to use instead of the install-config command.

https://access.redhat.com/solutions/5158831

https://access.redhat.com/sites/default/files/attachments/aws-internal-install-config.yml

This page has more info on the install process and limitations of private clusters:
https://docs.openshift.com/container-platform/4.5/installing/installing_aws/installing-aws-private.html

First create the install-config yaml file and back it up as it is consumed by manifest creation.
Note: from here out all commands are run from the openshift_windows_cluster directory unless otherwise stated.

$ mkdir ~/openshift_windows_cluster && cd ~/openshift_windows_cluster

$ openshift-install create install-config
? Platform aws
INFO Credentials loaded from the "default" profile in file "/home/ec2-user/.aws/credentials"
? Region us-east-2
? Base Domain example.com
? Cluster Name win-test-cluster
? Pull Secret [? for help] (Paste your Pull Secret from the Red Hat web site or text file you downloaded)

$ sed -i 's/OpenShiftSDN/OVNKubernetes/g' install-config.yaml

$ cp -p install-config.yaml install-config.yaml.backup

Now we can create the manifest files and set up the OVN CNI settings:

$ openshift-install create manifests
INFO Credentials loaded from the "default" profile in file "/home/ec2-user/.aws/credentials"
INFO Consuming Install Config from target directory

$ cp -p manifests/cluster-network-02-config.yml manifests/cluster-network-03-config.yml

$ vi manifests/cluster-network-03-config.yml

The important things to change in this file are the apiVersion and defaultNetwork settings. It is important that the hybrid cluster network CIDR does not overlap with the cluster network CIDR. If you are following this guide exactly you can use this our network config file.

Here are the contents of our manifests/cluster-network-03-config.yml file:

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  creationTimestamp: null
  name: cluster
spec:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  externalIP:
    policy: {}
  networkType: OVNKubernetes
  serviceNetwork:
  - 172.30.0.0/16
  defaultNetwork:
    type: OVNKubernetes
    ovnKubernetesConfig:
      hybridOverlayConfig:
        hybridClusterNetwork:
        - cidr: 10.132.0.0/14
          hostPrefix: 23
status: {}

Creation of the Cluster

With those files in place we can now create the cluster. Take a coffee break, this will take around 30 minutes to complete.

$ openshift-install create cluster
INFO Consuming Openshift Manifests from target directory
INFO Consuming Worker Machines from target directory
INFO Consuming Master Machines from target directory
INFO Consuming OpenShift Install (Manifests) from target directory
INFO Consuming Common Manifests from target directory
INFO Credentials loaded from the "default" profile in file "/home/ec2-user/.aws/credentials"
INFO Creating infrastructure resources...
INFO Waiting up to 20m0s for the Kubernetes API at https://api.win-test-cluster.example.com:6443...
INFO API v1.18.3+5302882 up
INFO Waiting up to 40m0s for bootstrapping to complete...
INFO Destroying the bootstrap resources...
INFO Waiting up to 30m0s for the cluster at https://api.win-test-cluster.example.com:6443 to initialize...
I1015 22:40:12.502855 1042 trace.go:116] Trace[1959950141]: "Reflector ListAndWatch" name:k8s.io/client-go/tools/watch/informerwatcher.go:146 (started: 2020-10-15
22:39:55.810110164 +0000 UTC m=+886.539985514) (total time: 16.692708687s):
Trace[1959950141]: [16.692655552s] [16.692655552s] Objects listed

INFO Waiting up to 10m0s for the openshift-console route to be created...
INFO Install complete!
INFO To access the cluster as the system:admin user when using 'oc', run 'export KUBECONFIG=/home/ec2-user/openshift_windows_cluster/auth/kubeconfig'
INFO Access the OpenShift web-console here: https://console-openshift-console.apps.win-test-cluster.example.com
INFO Login to the console with user: "kubeadmin", and password: "XXXXX-XXXXX-XXXXX-XXXXX"
INFO Time elapsed: 30m48s

Now you can run the export command and start using oc commands.

$ export KUBECONFIG=/home/ec2-user/openshift_windows_cluster/auth/kubeconfig
$ oc get nodes
NAME STATUS ROLES AGE VERSION
ip-10-0-128-115.us-east-2.compute.internal Ready master 1h v1.18.3+970c1b3
ip-10-0-150-141.us-east-2.compute.internal Ready worker 1h v1.18.3+970c1b3
ip-10-0-161-110.us-east-2.compute.internal Ready worker 1h v1.18.3+970c1b3
ip-10-0-186-69.us-east-2.compute.internal Ready master 1h v1.18.3+970c1b3
ip-10-0-201-57.us-east-2.compute.internal Ready master 1h v1.18.3+970c1b3
ip-10-0-220-129.us-east-2.compute.internal Ready worker 1h v1.18.3+970c1b3
$ oc version
Client Version: 4.5.14
Server Version: 4.5.14
Kubernetes Version: v1.18.3+5302882

To verify you have the proper network running you can run this command:

 $ oc get network.operator cluster -o yaml

Look at the spec section of the yaml output. It should look like this.

spec:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  defaultNetwork:
    ovnKubernetesConfig:
      hybridOverlayConfig:
        hybridClusterNetwork:
        - cidr: 10.132.0.0/14
          hostPrefix: 23
    type: OVNKubernetes
serviceNetwork:
- 172.30.0.0/16

Bootstrapping the Windows Worker Nodes

If you already have an SSH keypair in AWS you can use that, if not you can generate a new one with the steps below. Note that you cannot use a key with a passphrase for Windows machines.

$ ssh-keygen -t rsa -b 4096 -N "" -C "example-key" -f ~/.ssh/example-key

$ aws --region us-east-2 ec2 import-key-pair --key-name "example-key" --public-key-material file://$HOME/.ssh/example-key.pub

Now we need to download the Windows node bootstrapper and create our Windows nodes. This will take about 5 minutes to run.

See this page for the latest releases: https://github.com/openshift/windows-machine-config-bootstrapper/releases

See this page for more info on wni: https://github.com/openshift/windows-machine-config-bootstrapper/tree/master/tools/windows-node-installer

Note: Due to a bug in the Intel 82599 network adapter used in most Intel based instances that causes issues with overlay networks, we suggest using AMD based instances like m5a.large

$ wget https://github.com/openshift/windows-machine-config-bootstrapper/releases/download/v4.5.2-alpha/wni -O ~/bin/wni

$ chmod +x ~/bin/wni && mkdir windowsnodeinstaller

$ wni aws create --kubeconfig $KUBECONFIG --credentials ~/.aws/credentials --credential-account default --instance-type m5a.large --ssh-key example-key --private-key ~/.ssh/example-key --dir ./windowsnodeinstaller/
2020/10/16 20:05:13 kubeconfig source: /home/ec2-user/openshift_windows_cluster/auth/kubeconfig
2020/10/16 20:05:14 Added rule with port 5986 to the security groups of your local IP
2020/10/16 20:05:14 Added rule with port 22 to the security groups of your local IP
2020/10/16 20:05:14 Added rule with port 3389 to the security groups of your local IP
2020/10/16 20:05:14 Using existing Security Group: sg-0123456789012345
2020/10/16 20:09:41 External IP: 4.138.182.84
2020/10/16 20:09:41 Internal IP: 10.0.42.50

After creating the node we can get the login info and run Ansible to finish node setup.

See this page for more information: https://github.com/openshift/windows-machine-config-bootstrapper/tree/master/tools/ansible

Get the Windows node Instance ID from the json file and get the Windows Administrator password. This password can also be used for RDP.

$ cat windowsnodeinstaller/windows-node-installer.json
{"InstanceIDs":["i-0123456789012345"],"SecurityGroupIDs":["sg-0123456789012345"]}

$ aws ec2 get-password-data --instance-id i-0123456789012345 --priv-launch-key ~/.ssh/example-key

Ansible Windows Node Finalization

Now we need to create an Ansible inventory file.

 $ vi inventory.ini

Your file should look like this, with your Windows node password and node address. Be sure to put the password in single quotes and set the cluster address to match the name of your cluster and private IP to match your node as well.

[win]
4.138.182.84 ansible_password='YOURWINDOWSNODEPASSWORDHERE' private_ip=10.0.42.50

[win:vars]
ansible_user=Administrator
cluster_address=win-test-cluster.example.com
ansible_connection=winrm
ansible_ssh_port=5986
ansible_winrm_server_cert_validation=ignore

Verify Ansible connectivity with this command and look for SUCCESS in the output:

$ ansible win -i inventory.ini -m win_ping
4.138.182.84 | SUCCESS => {
"changed": false,
"ping": "pong"
}

Clone the Windows Machine Config Bootstrapper repo and run the ansible playbook against the node:

$ git clone https://github.com/openshift/windows-machine-config-bootstrapper.git

$ ansible-playbook -v -i inventory.ini windows-machine-config-bootstrapper/tools/ansible/tasks/wsu/main.yaml

This will produce a lot of output and take 10 minutes or so. In the end you should see the Play Recap. As long as 'failed=0' then everything should be good.

To check the node is good and working in the cluster run this command:

$ oc get nodes -o wide -l kubernetes.io/os=windows
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
ip-10-0-42-50.us-east-2.compute.internal Ready worker 29m v1.18.3 10.0.42.50 3.138.182.84 Windows Server 2019 Datacenter 10.0.17763.1518 docker://19.3.12

At this point you should use RDP to connect to the Windows worker node using the Administrator user and the password you pulled earlier. Just add the Windows Worker Node to a security group allowing RDP and then open a connection. After logging in start a powershell session with admin rights and run 'docker ps'.

Deploy a Windows sample application:

$ oc create -f https://raw.githubusercontent.com/keyvatech/blog_files/master/kubernetes_windows_web_server.yaml -n default

You can check it is running in OpenShift with this command:

$oc rollout status deployment win-webserver -n default
deployment "win-webserver" successfully rolled out

On Windows docker output should look like this:

PS C:\Users\Administrator> docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
09c8bbd2a7e8 mcr.microsoft.com/windows/servercore "powershell.exe -com…" 13 minutes ago Up 13 minutes k8s_windowswebserver_win-webserver-85b49f8677-cgqkq_default_01fe28db-5ae7-4ead-8e84-5d9d5cd2cb01_0
52d42f33de9d mcr.microsoft.com/k8s/core/pause:1.2.0 "cmd /S /C 'cmd /c p…" 16 minutes ago Up 16 minutes k8s_POD_win-webserver-85b49f8677-cgqkq_default_01fe28db-5ae7-4ead-8e84-5d9d5cd2cb01_0

If you have any issues try waiting 15 minutes and then redeploying with one of the following commands:

$ oc rollout restart deployment/win-webserver
$ oc rollout retry deployment/win-webserver

To look at logs for the container, do this:

$ oc get pods
NAME READY STATUS RESTARTS AGE
win-webserver-564d75c5f7-l4kk2 1/1 Running 0 96s
$ oc logs win-webserver-564d75c5f7-l4kk2
Listening at http://*:80/

After the application is up and running DNS will take up to 5 minutes to populate. So if this doesn't work try again. Check the service is up and running by getting the external IP for the service and curling it.

$ oc get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 172.30.0.1 <none> 443/TCP 23h
openshift ExternalName <none> kubernetes.default.svc.cluster.local <none> 23h
win-webserver LoadBalancer 172.30.88.146 a038a9aa4571f4a7cafaf15ebf7ae270-23672059.us-east-2.elb.amazonaws.com 80:32601/TCP 35m
$ curl a038a9aa4571f4a7cafaf15ebf7ae270-23672059.us-east-2.elb.amazonaws.com
<html><body><H1>Windows Container Web Server</H1></body></html>

Deleting the Cluster

If you're all done and want to tear down here are the commands:

$ wni aws destroy --kubeconfig $KUBECONFIG --credentials ~/.aws/credentials --credential-account default --dir ./windowsnodeinstaller/

$ openshift-install destroy cluster

If you have any questions about the steps documented here, or have any feedback or requests, please let us know at info@keyvatech.com.

By Brad Johnson, Lead DevOps Engineer

This guide covers how to set up an OpenShift cluster in AWS with Windows worker nodes. Because this requires the OVN Kubernetes container network interface you can not simply add Windows nodes to existing clusters. Please also understand that this functionality is still considered to be preview or beta from Red Hat is not supported in production environments at this time. This functionality also requires using OpenShift 4.4 or later, we tested this using OpenShift 4.5, which was the latest when this was published.

Requirements:
- Ansible 2.9+
- Python 3
- Python winrm module
- AWS CLI
- OpenShift 4.4+
- OC CLI 4.4+
- GIT
- AWS IAM User with programmatic access key and AdministratorAccess policy attached

Environment Setup:
If you don't have an environment that meets the above specs then create an EC2 instance with Amazon Linux 2.
I used a t2.micro instance and a security group allowing SSH on port 22. This environment already has the AWS CLI set up. During my run I only needed 4GB total disk space so the default disk size is fine.

After the instance is launched, SSH to the new VM as 'ec2-user' using your keyfile.
Run the following commands to set up python pre-reqs:

$ sudo yum install python3 python3-pip git
$ pip3 install --user pywinrm ansible

Navigate to https://cloud.redhat.com/openshift/install/aws/installer-provisioned and log in with your Red Hat account. This page provides links to the latest installer and CLI. You will also need to download your pull secret from here. These are correct as of Oct 2020, however if you have an issue, please use the links on the latest page from Red Hat.

Download OpenShift CLI and Installer and place the binaries in the $PATH. Note: /home/ec2-user/bin is in the default of $PATH on AMZ Linux 2 and openshift-client also contains a kubectl binary.

$ cd ~

$ wget https://mirror.openshift.com/pub/openshift-v4/clients/ocp/latest/openshift-client-linux.tar.gz

$ mkdir bin && tar -xvf openshift-client-linux.tar.gz --directory bin && mv bin/README.md ~/openshift-client-README.md

$ wget https://mirror.openshift.com/pub/openshift-v4/clients/ocp/latest/openshift-install-linux.tar.gz

$ tar -xvf openshift-install-linux.tar.gz --directory bin && mv bin/README.md ~/openshift-install-README.md

Check the versions of the pre-reqs. Here is the output from when I tested this example as well.

$ ansible --version
ansible 2.10.2
config file = None
configured module search path = ['/home/ec2-user/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
ansible python module location = /home/ec2-user/.local/lib/python3.7/site-packages/ansible
executable location = /home/ec2-user/.local/bin/ansible
python version = 3.7.9 (default, Aug 27 2020, 21:59:41) [GCC 7.3.1 20180712 (Red Hat 7.3.1-9)]

$ aws --version
aws-cli/1.18.107 Python/2.7.18 Linux/4.14.193-149.317.amzn2.x86_64 botocore/1.17.31

$ oc version
Client Version: 4.5.14

$ openshift-install version
openshift-install 4.5.14
built from commit 9893a482f310ee72089872f1a4caea3dbec34f28
release image quay.io/openshift-release-dev/ocp-release@sha256:95cfe9273aecb9a0070176210477491c347f8e69e41759063642edf8bb8aceb6

$ kubectl version
Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.2-0-g52c56ce", GitCommit:"d7f3ccf9a5bdc96ba92e31526cf014b3de4c46aa", GitTreeState:"clean", BuildDate:"2020-09-16T15:25:59Z", GoVersion:"go1.13.4", Compiler:"gc", Platform:"linux/amd64"}

$ pip3 freeze
ansible==2.10.1
ansible-base==2.10.2
certifi==2020.6.20
cffi==1.14.3
chardet==3.0.4
cryptography==3.1.1
idna==2.10
Jinja2==2.11.2
MarkupSafe==1.1.1
ntlm-auth==1.5.0
packaging==20.4
pycparser==2.20
pyparsing==2.4.7
pywinrm==0.4.1
PyYAML==5.3.1
requests==2.24.0
requests-ntlm==1.1.0
six==1.15.0
urllib3==1.25.10
xmltodict==0.12.0

$ pip3 show pywinrm
Name: pywinrm
Version: 0.4.1
Summary: Python library for Windows Remote Management
Home-page: http://github.com/diyan/pywinrm/
Author: Alexey Diyan
Author-email: alexey.diyan@gmail.com
License: MIT license
Location: /home/ec2-user/.local/lib/python3.7/site-packages
Requires: xmltodict, requests, requests-ntlm, six

Configure the AWS and the AWS CLI

You will need an AWS IAM user with a programmatic access key and the AdministratorAccess policy attached. You will also need to set up Route53 for a public cluster, but this is not reqiured, if you wish to create a private cluster see our steps below.
See this page for information on setting up your AWS account. https://docs.openshift.com/container-platform/4.5/installing/installing_aws/installing-aws-account.html

If you need information on names for availability zones you can run one of the following commands.
Be sure you are using a region supported by RedHat for Openshift on the AWS.

$ aws ec2 describe-regions
$ aws ec2 describe-availability-zones --region us-east-2
$ aws ec2 describe-availability-zones --all-availability-zones

Run these commands to set up the AWS CLI

$ aws configure
AWS Access Key ID [None]: YOURACCESSKEYID
AWS Secret Access Key [None]: YOURSECRETACCESSKEY
Default region name [None]: us-east-2
Default output format [None]: json

We are now ready to set up the OpenShift Cluster. Please go to 'Creating an OpenShift Cluster in AWS with Windows Worker Nodes (Part II)'.

Helpful links: 

https://cloud.redhat.com/openshift/install/

If you are interested in deploying Windows worker nodes with Rancher,  please see our post here.

If you have any questions about the steps documented here, or have any feedback or requests, please let us know at info@keyvatech.com.