Using Bring-Your-Own-Host (BYOH) Windows instances as nodes

Creating a BYOH Windows instance requires creating a config map in the WMCO namespace.

Prerequisites

Any Windows instances that are to be attached to the cluster as a node must fulfill the following requirements:

• The Docker container runtime must be installed on the instance.

• The instance must be on the same network as the Linux worker nodes in the cluster.

• Port 22 must be open and running an SSH server.

• An administrator user is present with the private key used in the secret set as an authorized SSH key.

• The hostname of the instance must follow the RFC 1123 DNS label requirements, which include the following standards:

  • Contains only lowercase alphanumeric characters or ‘-‘.

  • Starts with an alphanumeric character.

  • Ends with an alphanumeric character.

1. Create a ConfigMap named windows-instances in the WMCO namespace that describes the Windows instances to be added.

   Example config map

   1	An address to SSH in to the instance with. This can be a DNS name or an IPv4 address. A PTR record must exist corresponding to the address used in the config map resolving to the instance host name for successful reverse DNS lookups.
   2	The name of the administrator user created in the prerequisites.

Removing BYOH Windows instances

You can remove BYOH instances attached to the cluster by deleting the instance’s entry in the config map. Deleting an instance reverts that instance back to its state prior to adding to the cluster. Any logs and container runtime artifacts are not added to these instances.

For an instance to be cleanly removed, it must be accessible with the current private key provided to WMCO. For example, to remove the 10.1.42.1 instance from the previous example, the config map would be changed to the following:

apiVersion: v1
metadata:
  name: windows-instances
data:
  instance.dns.com: |-

Deleting is viewed as a request to deconstruct all Windows instances added as nodes.