kubernetes/staging/src/k8s.io/client-go/util/csaupgrade/upgrade.go

// Finds all managed fields owners of the given operation type which owns all of
// the fields in the given set
//
// If there is an error decoding one of the fieldsets for any reason, it is ignored
// and assumed not to match the query.
func FindFieldsOwners(
	managedFields []metav1.ManagedFieldsEntry,
	operation metav1.ManagedFieldsOperationType,
	fields *fieldpath.Set,
) []metav1.ManagedFieldsEntry { … }

// Upgrades the Manager information for fields managed with client-side-apply (CSA)
// Prepares fields owned by `csaManager` for 'Update' operations for use now
// with the given `ssaManager` for `Apply` operations.
//
// This transformation should be performed on an object if it has been previously
// managed using client-side-apply to prepare it for future use with
// server-side-apply.
//
// Caveats:
//  1. This operation is not reversible. Information about which fields the client
//     owned will be lost in this operation.
//  2. Supports being performed either before or after initial server-side apply.
//  3. Client-side apply tends to own more fields (including fields that are defaulted),
//     this will possibly remove this defaults, they will be re-defaulted, that's fine.
//  4. Care must be taken to not overwrite the managed fields on the server if they
//     have changed before sending a patch.
//
// obj - Target of the operation which has been managed with CSA in the past
// csaManagerNames - Names of FieldManagers to merge into ssaManagerName
// ssaManagerName - Name of FieldManager to be used for `Apply` operations
func UpgradeManagedFields(
	obj runtime.Object,
	csaManagerNames sets.Set[string],
	ssaManagerName string,
	opts ...Option,
) error { … }

// Calculates a minimal JSON Patch to send to upgrade managed fields
// See `UpgradeManagedFields` for more information.
//
// obj - Target of the operation which has been managed with CSA in the past
// csaManagerNames - Names of FieldManagers to merge into ssaManagerName
// ssaManagerName - Name of FieldManager to be used for `Apply` operations
//
// Returns non-nil error if there was an error, a JSON patch, or nil bytes if
// there is no work to be done.
func UpgradeManagedFieldsPatch(
	obj runtime.Object,
	csaManagerNames sets.Set[string],
	ssaManagerName string,
	opts ...Option,
) ([]byte, error) { … }

// Returns a copy of the provided managed fields that has been migrated from
// client-side-apply to server-side-apply, or an error if there was an issue
func upgradedManagedFields(
	managedFields []metav1.ManagedFieldsEntry,
	csaManagerName string,
	ssaManagerName string,
	opts options,
) ([]metav1.ManagedFieldsEntry, error) { … }

// Locates an Update manager entry named `csaManagerName` with the same APIVersion
// as the manager at the targetIndex. Unions both manager's fields together
// into the manager specified by `targetIndex`. No other managers are modified.
func unionManagerIntoIndex(
	entries []metav1.ManagedFieldsEntry,
	targetIndex int,
	csaManagerName string,
	opts options,
) error { … }

func findFirstIndex[T any](
	collection []T,
	predicate func(T) bool,
) (int, bool) { … }

func filter[T any](
	collection []T,
	predicate func(T) bool,
) []T { … }

// Included from fieldmanager.internal to avoid dependency cycle
// FieldsToSet creates a set paths from an input trie of fields
func decodeManagedFieldsEntrySet(f metav1.ManagedFieldsEntry) (s fieldpath.Set, err error) { … }

// SetToFields creates a trie of fields from an input set of paths
func encodeManagedFieldsEntrySet(f *metav1.ManagedFieldsEntry, s fieldpath.Set) (err error) { … }