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Write resources through MCP

MCP write tools change live cluster state. Read the current resource before an update and review the returned object after it.

Patch a controller

Section titled “Patch a controller”

update_controller applies only the fields supplied. Common fields have named arguments. Other mutable controller fields belong in spec:

{
  "namespace": "teams-platform",
  "name": "demo",
  "version": "2.555",
  "hibernation": {
    "enabled": true,
    "gracePeriodMinutes": 60
  },
  "spec": {
    "resources": {
      "limits": {"cpu": "4", "memory": "8Gi"}
    },
    "probes": {
      "startup": {"periodSeconds": 20}
    }
  }
}

Nested objects merge by key. Omitted fields remain unchanged. A named argument wins when spec contains the same field. Unrecognized top-level arguments are rejected.

Named arguments do not clear values. Put an empty value or null in spec to clear a field. For example, {"spec": {"hibernation": null}} removes the hibernation configuration. The named form {"hibernation": null} does not: a named argument is read only when it carries an object, so a null is dropped and the request silently changes nothing.

Create tools and updates for other resources may apply a complete object. Read the discovered tool description before relying on omission behavior.

Hibernate or wake a controller

Section titled “Hibernate or wake a controller”

Use hibernate_controller and wake_controller. Hibernation is reported in status.hibernated; it is not a spec.powerState value. Both actions are rejected while powerState is Stopped and require controllers:manage.

Manage field ownership

Section titled “Manage field ownership”

Controller spec writes use Kubernetes server-side apply with field manager varroa-ui. If another manager owns a changed field, Varroa returns 409 and lists the field path and owning manager. No requested changes are applied.

Resolve the conflict in this order:

  1. Read the resource and identify the competing manager.
  2. Decide which system should own the field.
  3. Stop the other writer or remove the field from this request when it should keep ownership.
  4. Retry update_controller with force: true only when Varroa should take ownership.
{
  "namespace": "teams-platform",
  "name": "demo",
  "version": "2.555",
  "force": true
}

force changes ownership handling only. It does not change the patch content. It is accepted only by update_controller. Hibernate and wake actions update status, so they do not participate in spec ownership.

The REST equivalent is PATCH .../controllers/<namespace>/<name>?force=true. The varroactl equivalent is --force on supported controller update or edit commands.

Section titled “Related pages”