Files
kustomize/cmd/kubectl/kubectlcobra/grouping.go
2020-01-21 15:18:22 -08:00

269 lines
8.2 KiB
Go

// Copyright 2020 The Kubernetes Authors.
// SPDX-License-Identifier: Apache-2.0
// package kubectlcobra contains cobra commands from kubectl
package kubectlcobra
import (
"fmt"
"hash/fnv"
"sort"
"strconv"
"strings"
"k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/cli-runtime/pkg/resource"
)
const (
GroupingLabel = "kustomize.config.k8s.io/inventory-id"
GroupingHash = "kustomize.config.k8s.io/inventory-hash"
)
// retrieveGroupingLabel returns the string value of the GroupingLabel
// for the passed object. Returns error if the passed object is nil or
// is not a grouping object.
func retrieveGroupingLabel(obj runtime.Object) (string, error) {
var groupingLabel string
if obj == nil {
return "", fmt.Errorf("Grouping object is nil.\n")
}
accessor, err := meta.Accessor(obj)
if err != nil {
return "", err
}
labels := accessor.GetLabels()
groupingLabel, exists := labels[GroupingLabel]
if !exists {
return "", fmt.Errorf("Grouping label does not exist for grouping object: %s\n", GroupingLabel)
}
return strings.TrimSpace(groupingLabel), nil
}
// isGroupingObject returns true if the passed object has the
// grouping label.
// TODO(seans3): Check type is ConfigMap.
func isGroupingObject(obj runtime.Object) bool {
if obj == nil {
return false
}
groupingLabel, err := retrieveGroupingLabel(obj)
if err == nil && len(groupingLabel) > 0 {
return true
}
return false
}
// findGroupingObject returns the "Grouping" object (ConfigMap with
// grouping label) if it exists, and a boolean describing if it was found.
func findGroupingObject(infos []*resource.Info) (*resource.Info, bool) {
for _, info := range infos {
if info != nil && isGroupingObject(info.Object) {
return info, true
}
}
return nil, false
}
// sortGroupingObject reorders the infos slice to place the grouping
// object in the first position. Returns true if grouping object found,
// false otherwise.
func sortGroupingObject(infos []*resource.Info) bool {
for i, info := range infos {
if info != nil && isGroupingObject(info.Object) {
// If the grouping object is not already in the first position,
// swap the grouping object with the first object.
if i > 0 {
infos[0], infos[i] = infos[i], infos[0]
}
return true
}
}
return false
}
// Adds the inventory of all objects (passed as infos) to the
// grouping object. Returns an error if a grouping object does not
// exist, or we are unable to successfully add the inventory to
// the grouping object; nil otherwise. Each object is in
// unstructured.Unstructured format.
func addInventoryToGroupingObj(infos []*resource.Info) error {
// Iterate through the objects (infos), creating an Inventory struct
// as metadata for each object, or if it's the grouping object, store it.
var groupingInfo *resource.Info
var groupingObj *unstructured.Unstructured
inventoryMap := map[string]string{}
for _, info := range infos {
obj := info.Object
if isGroupingObject(obj) {
// If we have more than one grouping object--error.
if groupingObj != nil {
return fmt.Errorf("Error--applying more than one grouping object.")
}
var ok bool
groupingObj, ok = obj.(*unstructured.Unstructured)
if !ok {
return fmt.Errorf("Grouping object is not an Unstructured: %#v", groupingObj)
}
groupingInfo = info
} else {
if obj == nil {
return fmt.Errorf("Creating inventory; object is nil")
}
gk := obj.GetObjectKind().GroupVersionKind().GroupKind()
inventory, err := createInventory(info.Namespace, info.Name, gk)
if err != nil {
return err
}
inventoryMap[inventory.String()] = ""
}
}
// If we've found the grouping object, store the object metadata inventory
// in the grouping config map.
if groupingObj == nil {
return fmt.Errorf("Grouping object not found")
}
if len(inventoryMap) > 0 {
// Adds the inventory map to the ConfigMap "data" section.
err := unstructured.SetNestedStringMap(groupingObj.UnstructuredContent(),
inventoryMap, "data")
if err != nil {
return err
}
// Adds the hash of the inventory strings as an annotation to the
// grouping object. Inventory strings must be sorted to make hash
// deterministic.
inventoryList := mapKeysToSlice(inventoryMap)
sort.Strings(inventoryList)
invHash, err := calcInventoryHash(inventoryList)
if err != nil {
return err
}
// Add the hash as a suffix to the grouping object's name.
invHashStr := strconv.FormatUint(uint64(invHash), 16)
if err := addSuffixToName(groupingInfo, invHashStr); err != nil {
return err
}
annotations := groupingObj.GetAnnotations()
if annotations == nil {
annotations = map[string]string{}
}
annotations[GroupingHash] = invHashStr
groupingObj.SetAnnotations(annotations)
}
return nil
}
// retrieveInventoryFromGroupingObj returns a slice of pointers to the
// inventory metadata. This function finds the grouping object, then
// parses the stored resource metadata into Inventory structs. Returns
// an error if there is a problem parsing the data into Inventory
// structs, or if the grouping object is not in Unstructured format; nil
// otherwise. If a grouping object does not exist, or it does not have a
// "data" map, then returns an empty slice and no error.
func retrieveInventoryFromGroupingObj(infos []*resource.Info) ([]*Inventory, error) {
inventory := []*Inventory{}
groupingInfo, exists := findGroupingObject(infos)
if exists {
groupingObj, ok := groupingInfo.Object.(*unstructured.Unstructured)
if !ok {
err := fmt.Errorf("Grouping object is not an Unstructured: %#v", groupingObj)
return inventory, err
}
invMap, exists, err := unstructured.NestedStringMap(groupingObj.Object, "data")
if err != nil {
err := fmt.Errorf("Error retrieving inventory from grouping object.")
return inventory, err
}
if exists {
for invStr := range invMap {
inv, err := parseInventory(invStr)
if err != nil {
return inventory, err
}
inventory = append(inventory, inv)
}
}
}
return inventory, nil
}
// calcInventoryHash returns an unsigned int32 representing the hash
// of the inventory strings. If there is an error writing bytes to
// the hash, then the error is returned; nil is returned otherwise.
// Used to quickly identify the set of resources in the grouping object.
func calcInventoryHash(inv []string) (uint32, error) {
h := fnv.New32a()
for _, is := range inv {
_, err := h.Write([]byte(is))
if err != nil {
return uint32(0), err
}
}
return h.Sum32(), nil
}
// retrieveInventoryHash takes a grouping object (encapsulated by
// a resource.Info), and returns the string representing the hash
// of the grouping inventory; returns empty string if the grouping
// object is not in Unstructured format, or if the hash annotation
// does not exist.
func retrieveInventoryHash(groupingInfo *resource.Info) string {
var invHash = ""
groupingObj, ok := groupingInfo.Object.(*unstructured.Unstructured)
if ok {
annotations := groupingObj.GetAnnotations()
if annotations != nil {
invHash = annotations[GroupingHash]
}
}
return invHash
}
// mapKeysToSlice returns the map keys as a slice of strings.
func mapKeysToSlice(m map[string]string) []string {
s := make([]string, len(m))
i := 0
for k := range m {
s[i] = k
i++
}
return s
}
// addSuffixToName adds the passed suffix (usually a hash) as a suffix
// to the name of the passed object stored in the Info struct. Returns
// an error if the object is not "*unstructured.Unstructured" or if the
// name stored in the object differs from the name in the Info struct.
func addSuffixToName(info *resource.Info, suffix string) error {
if info == nil {
return fmt.Errorf("Nil resource.Info")
}
suffix = strings.TrimSpace(suffix)
if len(suffix) == 0 {
return fmt.Errorf("Passed empty suffix")
}
accessor, _ := meta.Accessor(info.Object)
name := accessor.GetName()
if name != info.Name {
return fmt.Errorf("Grouping object (%s) and resource.Info (%s) have different names\n", name, info.Name)
}
// Error if name alread has suffix.
suffix = "-" + suffix
if strings.HasSuffix(name, suffix) {
return fmt.Errorf("Name already has suffix: %s\n", name)
}
name += suffix
accessor.SetName(name)
info.Name = name
return nil
}