kubernetes/cmd/kubeadm/app/phases/upgrade/health.go

const createJobHealthCheckPrefix …

type healthCheck …

// Check is part of the preflight.Checker interface
func (c *healthCheck) Check() (warnings, errors []error) { … }

// Name is part of the preflight.Checker interface
func (c *healthCheck) Name() string { … }

// CheckClusterHealth makes sure:
// - the cluster can accept a workload
// - all control-plane Nodes are Ready
// - (if static pod-hosted) that all required Static Pod manifests exist on disk
func CheckClusterHealth(client clientset.Interface, cfg *kubeadmapi.ClusterConfiguration, ignoreChecksErrors sets.Set[string], dryRun bool, printer output.Printer) error { … }

// createJob is a check that verifies that a Job can be created in the cluster
func createJob(client clientset.Interface, cfg *kubeadmapi.ClusterConfiguration, _ bool, _ output.Printer) error { … }

// controlPlaneNodesReady checks whether all control-plane Nodes in the cluster are in the Running state
func controlPlaneNodesReady(client clientset.Interface, _ *kubeadmapi.ClusterConfiguration, _ bool, _ output.Printer) error { … }

// staticPodManifestHealth makes sure the required static pods are presents
func staticPodManifestHealth(_ clientset.Interface, _ *kubeadmapi.ClusterConfiguration, dryRun bool, printer output.Printer) error { … }

// getNotReadyNodes returns a string slice of nodes in the cluster that are NotReady
func getNotReadyNodes(nodes []v1.Node) []string { … }