From ba77eed7467fcc6c99d62fa3f7eb0318efcc947c Mon Sep 17 00:00:00 2001
From: Jose Valdes <jvaldes@redhat.com>
Date: Tue, 23 Sep 2025 09:05:00 -0400
Subject: [PATCH] [hack] add byoh-create-instance.sh script

This commit introduces a script to create a Windows Server VM on that
can be used as a Windows BYOH node.
---
 hack/byoh-create-instance.sh | 166 +++++++++++++++++++++++++++++++++++
 1 file changed, 166 insertions(+)
 create mode 100755 hack/byoh-create-instance.sh

diff --git a/hack/byoh-create-instance.sh b/hack/byoh-create-instance.sh
new file mode 100755
index 0000000000..30e61512b7
--- /dev/null
+++ b/hack/byoh-create-instance.sh
@@ -0,0 +1,166 @@
+#!/bin/bash
+#
+# Create a Windows BYOH (Bring Your Own Host) instance in OpenShift 4.x
+#
+# This script creates a Windows Server VM on that can be used as a Windows BYOH node.
+# It automatically extracts configuration and creates or updates the
+# windows-instances configmap with the private IP and the username of the new instance.
+#
+# Prerequisites:
+# - WMCO installed and running with windows-user-data secret created
+# - Azure CLI (az) installed and authenticated
+# - OpenShift CLI (oc) installed and authenticated to target cluster
+# - jq utility for JSON parsing
+# - base64 utility for decoding user data
+#
+# Usage:
+#   ./byoh-create-instance.sh
+#
+# Environment Variables (optional):
+#   WINDOWS_SERVER_VERSION - Windows Server version (default: 2019)
+#   DEBUG_FLAG - Set to "--debug" to enable debug output (default: "")
+#
+
+# exit the script if any command fails
+set -eo pipefail
+
+# check platform
+PLATFORM=$(oc get infrastructure cluster -o jsonpath='{.spec.platformSpec.type}')
+case "$PLATFORM" in
+    "Azure")
+        echo "Platform: $PLATFORM"
+        ;;
+    *)
+        echo "Error: platform not supported: $PLATFORM" >&2
+        exit 1
+        ;;
+esac
+
+# Read Windows Server version from environment variable, default to 2019
+WINDOWS_SERVER_VERSION=${WINDOWS_SERVER_VERSION:-2019}
+
+INSTANCE_NAME_SUFFIX=$(dd if=/dev/urandom bs=1 count=100 2>/dev/null | tr -dc 'a-z0-9' | head -c 4)
+INSTANCE_NAME="byoh-${WINDOWS_SERVER_VERSION}-${INSTANCE_NAME_SUFFIX}"
+SKU="${WINDOWS_SERVER_VERSION}-datacenter-smalldisk"
+PUBLISHER="MicrosoftWindowsServer"
+OFFER="WindowsServer"
+
+# default to latest version for Windows Server 2022
+VERSION="latest"
+if [ "$WINDOWS_SERVER_VERSION" = "2019" ]; then
+    # fix version for Windows Server 2019 otherwise
+    VERSION="17763.6293.240905"
+fi
+
+# build image name
+IMAGE="${PUBLISHER}:${OFFER}:${SKU}:${VERSION}"
+
+# fetch platform and network configuration from existing Linux worker machine
+LINUX_WORKER_SPECS=$(oc get machines -n openshift-machine-api -l machine.openshift.io/cluster-api-machine-role=worker -ojsonpath={.items[0].spec})
+REGION=$(echo "$LINUX_WORKER_SPECS" | jq -r .providerSpec.value.location)
+VNET_NAME=$(echo "$LINUX_WORKER_SPECS" | jq -r .providerSpec.value.vnet)
+SUBNET_NAME=$(echo "$LINUX_WORKER_SPECS" | jq -r .providerSpec.value.subnet)
+ZONE_NUMBER=$(echo "$LINUX_WORKER_SPECS" | jq -r .providerSpec.value.zone)
+
+# Decode Windows PowerShell bootstrap script
+WINDOWS_USER_DATA=$(oc get secret windows-user-data -n openshift-machine-api -o jsonpath='{.data.userData}' | base64 -d)
+# remove powershell tags
+WINDOWS_USER_DATA=$(echo "$WINDOWS_USER_DATA" | sed 's/<powershell>//' | sed 's/<\/powershell>//')
+# remove persist tags and content
+WINDOWS_USER_DATA=$(echo "${WINDOWS_USER_DATA}" | sed 's/<persist>true<\/persist>//')
+
+RESOURCE_GROUP=$(oc get infrastructure cluster -o jsonpath='{.status.platformStatus.azure.resourceGroupName}')
+
+ADMIN_USERNAME="capi"
+ADMIN_PASSWORD=$(dd if=/dev/urandom bs=1 count=101 2>/dev/null | tr -dc 'a-z0-9A-Z' | head -c 18)!
+
+DEBUG_FLAG=${DEBUG_FLAG:-""}
+
+
+echo "Creating VM '${INSTANCE_NAME}' with image '${IMAGE}' in resource group '${RESOURCE_GROUP}'"
+az vm create ${DEBUG_FLAG}  \
+    --resource-group "${RESOURCE_GROUP}" \
+    --name "${INSTANCE_NAME}" \
+    --image "${IMAGE}" \
+    --location "${REGION}" \
+    --admin-username "${ADMIN_USERNAME}" \
+    --admin-password "${ADMIN_PASSWORD}" \
+    --public-ip-address "" \
+    --public-ip-sku Standard \
+    --size "Standard_B2s" \
+    --os-disk-size-gb 128 \
+    --vnet-name "${VNET_NAME}" \
+    --subnet "${SUBNET_NAME}" \
+    --zone "${ZONE_NUMBER}"
+
+
+echo "Installing user data..."
+
+USER_DATA_OUTPUT=$(az vm run-command invoke \
+    --resource-group "${RESOURCE_GROUP}" \
+    --name "${INSTANCE_NAME}" \
+    --command-id "RunPowerShellScript" \
+    --scripts "${WINDOWS_USER_DATA}"
+)
+
+if [ -n "${DEBUG_FLAG}" ]; then
+    echo "User data installation output:"
+    echo "${USER_DATA_OUTPUT}" | jq -r '.value[].message' | sed 's/\\n/\n/g'
+    echo "${USER_DATA_OUTPUT}" | jq -r '.value[].code'
+    echo "${USER_DATA_OUTPUT}" | jq -r '.value[].displayStatus'
+fi
+
+
+PRIVATE_IPS=$(az vm show \
+    --resource-group "${RESOURCE_GROUP}" \
+    --name "${INSTANCE_NAME}" \
+    --show-details \
+    --query "privateIps" \
+    --output tsv)
+
+PRIVATE_IP=${PRIVATE_IPS%% *}
+if [ -n "${DEBUG_FLAG}" ]; then
+    echo "Found private IPs: ${PRIVATE_IPS}"
+    echo "Using private IP: ${PRIVATE_IP}"
+fi
+
+
+echo "Adding entry to windows-instances configmap with address ${PRIVATE_IP} and username ${ADMIN_USERNAME}"
+
+if oc get configmap windows-instances -n openshift-windows-machine-config-operator >/dev/null 2>&1; then
+    oc patch configmap windows-instances -n openshift-windows-machine-config-operator \
+        --type merge \
+        -p "{\"data\":{\"${PRIVATE_IP}\": \"username=${ADMIN_USERNAME}\"}}"
+else
+    echo "Creating new windows-instances ConfigMap..."
+    envsubst <<EOF | oc apply -f -
+kind: ConfigMap
+apiVersion: v1
+metadata:
+  name: windows-instances
+  namespace: openshift-windows-machine-config-operator
+data:
+   ${PRIVATE_IP}: |-
+    username=${ADMIN_USERNAME}
+EOF
+fi
+
+
+echo ""
+echo ""
+echo "To remove the instance from the cluster, run the following command:       "
+echo ""
+echo "   oc delete configmap windows-instances -n openshift-windows-machine-config-operator"
+echo ""
+echo ""
+
+echo ""
+echo ""
+echo "To delete the instance, run the following command:    "
+echo ""
+echo "   az vm delete --resource-group ${RESOURCE_GROUP} --name ${INSTANCE_NAME} --yes --no-wait"
+echo ""
+echo ""
+
+# success
+exit 0