Kubelet limit of Parallel Image Pulls

[ruiwen-zhao]

Enhancement Description

• One-line enhancement description (can be used as a release note): Add a node-level limit to kubelet to limit the number of parallel image pulls
• Kubernetes Enhancement Proposal: https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/3673-kubelet-parallel-image-pull-limit/README.md
• Discussion Link:
• Primary contact (assignee): @pacoxu (emeritus: @ruiwen-zhao)
• Responsible SIGs: SIG Node
• Enhancement target (which target equals to which milestone):
  • Alpha release target (x.y): 1.27
  • Beta release target (x.y): 1.32
  • Stable release target (x.y): 1.35
• Alpha
  • KEP (k/enhancements) update PR(s):
    • KEP-3673: Kubelet limit of Parallel Image Pulls #3713
  • Code (k/k) update PR(s):
    • Add MaxParallelImagePulls support kubernetes#115220
  • Docs (k/website) update PR(s):
    • Document update for MaxParallelImagePulls website#39732
• Beta
  • KEP (k/enhancements) update PR(s):
    • 1.28 KEP-3673: Promote Parallel Image Pull Limit to Beta #4036;
    • 1.29 update kubelet parallel image pull limit for v1.29 #4173
    • 1.30 postponed kep-3673 parallel image pull limit to v1.30 for beta #4452
    • 1.32 [cleanup] update KEP-3673 status: e2e added in v1.32 for beta #4938
  • Code (k/k) update PR(s):
    • 1.32 [node-e2e] add test cases for serialize and parallel image pulling kubernetes#121604
  • Docs (k/website) update(s): doc is merged a little earlier. E2E was added in v1.32.
    • Promote parallel image pulls to beta website#42061 merged in v1.28, and reverted).
    • update maxParallelImagePulls to beta website#48681
• Stable
  • KEP: promote kep-3673 to GA #5640
  • k/k: no update
  • docs: Update feature state for maximum parallel image pulls to stable website#52710

Related issues：

• Parallel image pull should pull unique images only once kubernetes#125164

[ruiwen-zhao]

/sig node

[pacoxu]

Some intial ideas can be found in https://docs.google.com/document/d/1MMZlKSxkDBDz0kEn9JGm848_IJgydJqXWz5t9D3Ev8I/edit# and kubernetes/kubernetes#112242 kubernetes/kubernetes#112044

[wojtek-t]

/lead opted-in
/milestone v1.27

[wojtek-t]

/label lead-opted-in