Reconciliation loop

Modules

Each time a new Module is created, we need to find to which nodes it applies.

1. A first filtering is performed using the .spec.selector field, then we go through the module’s kernel mappings to find a container image that matches the node’s kernel.

2. We end up with a certain number of (kernel, image) pairs; for each of these pairs, there should be a DaemonSet.

3. We first look for a DaemonSet that would already be targeting the same kernel and DriverContainer image (that data is stored in the DaemonSet’s labels).

4. If there is already such a DaemonSet, we patch it, if needed.

5. If there is not already a matching DaemonSet, we create it and set the Module as owner.

6. When a Module is deleted, we have nothing to do: because we set it as owner of all DaemonSets, Kubernetes garbage collection will take care of deleting them.

7. We watch Module, owned DaemonSet and build objects as well as nodes to make sure that we are not missing any change in the cluster.