VM Operator is an extension to Kubernetes that implements VM management through Kubernetes. It was released officially at end of April 2021 with vCenter Server 7.0 U2a. This is a small feature pushed through a vCenter Server patch that is bringing a huge shift in the paradigm of VM management. It changes the way we are looking at VMs and at the way we are using virtualization. One could argue that Kubernetes already did that. I would say that unifying resource consumption through VMs and pods is actually a huge step forward. VM Operator brings to play not only Infrastructure as Code (IaC), but it also enables GitOps for VMs.
Let's look briefly at the two concepts. IaC represents the capability to define your infrastructure in a human readable language. A lot of tools exist that enable IaC - Puppet, Chef, Ansible, Terraform and so on. They are complex and powerful tools, some of them used in conjunction with others. All these tools have a particularity: they have their own language - Ruby, Python, HCL. GitOps expands the IaC concept. In this case, Git repository is the only source of truth. Manifests (configuration files that describe the resource to be provisioned) are pushed to a Git repository monitored by a continuous deployment (CD) tool that ensures that changes in the repository are applied in the real world. Kubernetes enables GitOps. Kubernetes manifests are written in YAML. With introduction of VM Operator the two concepts can be used in conjunction. For example you could have a GitOps pipeline that deploys the VMs using Kubernetes manifests and then configuration management tools could actually make sure the VMs are customized to suit their purpose - deploying an application server, monitoring agents and so on.
In the current post we will only look at the basics of deploying a VM through VM Operator. Once these concepts are clear then you can add other tools such as Git repositories, CD tools, configuration management.
So, what do we need to be able to provision a VM through VM Operator?
We need vCenter Server updated to U2a and a running Supervisor cluster.
At namespace level a storage policies needs to be configured. It is needed for both VM deployment and persistent volumes
We need a content library uploaded with a supported VMware template (we will follow soon with a post on how to create unsupported VMware templates for VM operator). At the time of writing CentOS 8 and Ubuntu images are distributed through VMware Marketplace (https://marketplace.cloud.vmware.com/ search for "VM service Image")
The images are installed with cloud-init and configured to transport user data using OVF environment variables to cloud-init process which in turn customizes the VM operating system.
In Workload Management, VM Service allows the configuration of additional VM classes and content libraries. VM classes and content library are assigned to the namespace to be able to provision the VMs.
Content library selected for a particular namespace:
Once or the prerequisites are in place, connect to supervisor cluster, and select the namespace you want to deploy the VM
A VM provisioned via VM Operator can only be managed through the Supervisor cluster API (Kubernetes API). In this regard, the VM cannot be any longer managed directly from the UI or other management tools. Looking at the picture below you will notice that the VM is marked in UI as "Developer Managed" and that there are no actions that can be taken on the VM