kubernetes-sigs/cluster-api

Speed up provisioning of the first set of worker machines by improving predicates on cluster watch

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#8,835 opened on Jun 12, 2023

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area/bootstraphelp wantedkind/featurepriority/important-longtermtriage/accepted

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Description

What would you like to be added (User Story)?

As a users I want CAPI to provision machines as fast as possible

Detailed Description

While looking at cluster provisioning I noticed that the kubeadm bootstrap controller takes time to react to when the cluster reports control plane ready, which is the moment when workers machines are allowed to join.

From a preliminary investigation, the kubeadm bootstrap controller is watching for clusters, but existing predicates (more specifically predicates.ClusterUnpausedAndInfrastructureReady) are filtering out events when the cluster transition to control plane ready.

This issue is about investigating if we can speed up provisioning of the first set of worker machines by improving predicates

Anything else you would like to add?

Note predicates.ClusterUnpausedAndInfrastructureReady, so some research is required before changing this method, or most probably it is better to create a new one.

Label(s) to be applied

/kind feature /area bootstrap

Contributor guide

Research direction
Investigate the predicates.ClusterUnpausedAndInfrastructureReady function to understand why it filters out control plane ready transitions. Trace the watch setup in the kubeadm bootstrap controller and propose a new predicate that allows events when the cluster becomes ready for worker machines.
Tech stack
go
Domain
backendinfrastructure
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
GoKubernetes
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45