Taints Propagation Proposal implementation

[chrischdi]

This issue is for tracking progress of implementation for the taints propagation proposal:

• 📖 Propagating taints from Cluster API to Nodes #12329

We plan to split the implementation across Cluster API v1.12 and v1.13, which is considered safe because the changes will be feature-gated.

1.12:

• Machines (@chrischdi) :
  • Implement MachineSpec API changes (including validation)
  • Implement Machine controller changes
  • Implement unit-test coverage
  • PR: ✨ taint propagation: machine related API changes, conversion and feature gate #12936
• Implement e2e-test coverage for taints (@chrischdi)
  • Maybe fits into the MD Rollout test, make sure its easily portable to ClusterClass rollout test later on
  • PR: [WIP] 🌱 taint propagation: e2e coverage via md rollout test #12966
• Check the repository for the handling of the NodeDrainTimeoutSeconds field (prior art in-place propagation to Machine) and if same was applied for the Taints field.

1.13

• CABPK: implement merging behavior

  • discuss desired behavior: add to kubeadm config (which results in adding as --register-with-taints for kubelet / re-registration issue) or not

• ControlPlane contract:

  • Implement ControlPlane contract changes
  • Implement KCP changes to fulfill the contract
  • Implement test coverage
  • Check the repository for the handling of the NodeDrainTimeoutSeconds field (prior art in-place propagation to Machine) and if same was applied for the Taints field.

• topology:

  • Implement Cluster related API changes
  • Implement ClusterClass related API changes
  • Implement topology controller changes / field propagation
  • Check the repository for the handling of the NodeDrainTimeoutSeconds field (prior art in-place propagation to Machine) and if same was applied for the Taints field.

• Migrate e2e test coverage for taints from non-topology to topology

  • probably suites to ClusterClass rollout

• Migrate tracking annotation names to contain a internal prefix (for labels, annotations and taints tracking)

Additional work:

• Cluster autoscaler to be aware of the taints field
• MachinePool: implement MachinePool controller changes
  • Note: maybe should be tracked in MachinePool graduation tracking issue (edited)