The Manager

The Manager is the program that provides the controller from the operator pattern together with a web user interface. It should be run in a container in the cluster.

Installation

A manager instance manages the VMs in its own namespace. The only common (and therefore cluster scoped) resource used by all instances is the CRD. It is available here and must be created first.

kubectl apply -f https://github.com/mnlipp/VM-Operator/raw/main/deploy/crds/vms-crd.yaml

The example above uses the CRD from the main branch. This is okay if you apply it once. If you want to preserve the link for automatic upgrades, you should use a link that points to one of the release branches.

The next step is to create a namespace for the manager and the VMs, e.g. vmop-demo.

kubectl create namespace vmop-demo

Finally you have to create an account, the role, the binding etc. The default files for creating these resources using the default namespace can be found in the deploy directory. I recommend to use kustomize to create your own configuration.

Initial Configuration

Use one of the kustomize.yaml files from the example directory as a starting point. The directory contains two examples. Here’s the file from subdirectory local-path:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

resources:
# Again, I recommend to use the deploy directory from a
# release branch for anything but test environments.
- https://github.com/mnlipp/VM-Operator/deploy

namespace: vmop-demo

patches:
- patch: |-
    kind: PersistentVolumeClaim
    apiVersion: v1
    metadata:
      name: vmop-image-repository
    spec:
      # Default is ReadOnlyMany
      accessModes:
      - ReadWriteOnce
      resources:
        requests:
          # Default is 100Gi
          storage: 10Gi
      # Default is to use the default storage class
      storageClassName: local-path

- patch: |-
    kind: ConfigMap
    apiVersion: v1
    metadata:
      name: vm-operator
    data:
      config.yaml: |
        "/Manager":
          # "/GuiHttpServer":
            # See section about the GUI
          "/Controller":
            "/Reconciler":
              runnerDataPvc:
                # Default is to use the default storage class
                storageClassName: local-path

The sample file adds a namespace (vmop-demo) to all resource definitions and patches the PVC vmop-image-repository. This is a volume that is mounted into all pods that run a VM. The volume is intended to be used as a common repository for CDROM images. The PVC must exist and it must be bound before any pods can run.

The second patch affects the small volume that is created for each runner and contains the VM’s configuration data such as the EFI vars. The manager’s default configuration causes the PVC for this volume to be created with no storage class (which causes the default storage class to be used). The patch provides a new configuration file for the manager that makes the reconciler use local-path as storage class for this PVC. Details about the manager configuration can be found in the next section.

Note that you need none of the patches if you are fine with using your cluster’s default storage class and this class supports ReadOnlyMany as access mode.

Check that the pod with the manager is running:

kubectl -n vmop-demo get pods -l app.kubernetes.io/name=vm-operator

Proceed to the description of the controller for creating your first VM.

Configuration Details

The config map for the manager may provide a configuration file (config.yaml) and a file with logging properties (logging.properties). Both files are mounted into the container that runs the manager and are evaluated by the manager on startup. If no files are provided, the manager uses built-in defaults.

The configuration file for the Manager follows the conventions of the JGrapes component framework. The keys that start with a slash select the component within the application’s component hierarchy. The mapping associated with the selected component configures this component’s properties.

The available configuration options for the components can be found in their respective JavaDocs (e.g. here for the Reconciler).

Development Configuration

The dev-example directory contains a kustomize.yaml that uses the development namespace vmop-dev and creates a deployment for the manager with 0 replicas.

This environment can be used for running the manager in the IDE. As the namespace to manage cannot be detected from the environment, you must use -c ../dev-example/config.yaml as argument when starting the manager. This configures it to use the namespace vmop-dev.