Kubernetes Affinities, Taints and Tolerations as Filter/Weigher

[Varsius]

Description

Implement Kubernetes affinity, anti-affinity, and taints/tolerations in Cortex as filters or weighers in the scheduling pipeline to match the behavior of the default scheduler.

Objectives

• Enforce hard node constraints (nodeSelector, required nodeAffinity) via filtering
• Enforce hard pod affinity/anti-affinity via filtering
• Implement preference handling (soft/preferred nodeAffinity and podAffinity) as weighers
• Filter tainted nodes, unless tolerations apply
• Documentation

Acceptance Criteria

• Required node/pod affinity, anti-affinity, and taints/tolerations are enforced in the scheduling process
•  Preference rules noticeably influence weighing
•  Basic e2e tests

Dependencies

N/A

Additional Notes

• Documentation for affinity/anti-affinity
• Documentation for taints/tolerations