Move hashing code out of k8sdeps.

k8sdeps/transformer/hash/kusthash.go

@@ -4,13 +4,12 @@
 package hash
 
 import (
-	"crypto/sha256"
 	"encoding/json"
 	"fmt"
-	"sort"
 
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"sigs.k8s.io/kustomize/pkg/hasher"
 )
 
 // kustHash computes a hash of an unstructured object.
@@ -54,7 +53,7 @@ func configMapHash(cm *v1.ConfigMap) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	h, err := encodeHash(hash(encoded))
+	h, err := hasher.Encode(hasher.Hash(encoded))
 	if err != nil {
 		return "", err
 	}
@@ -68,22 +67,7 @@ func secretHash(sec *v1.Secret) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	h, err := encodeHash(hash(encoded))
-	if err != nil {
-		return "", err
-	}
-	return h, nil
-}
-
-// SortArrayAndComputeHash sorts a string array and
-// returns a hash for it
-func SortArrayAndComputeHash(s []string) (string, error) {
-	sort.Strings(s)
-	data, err := json.Marshal(s)
-	if err != nil {
-		return "", err
-	}
-	h, err := encodeHash(hash(string(data)))
+	h, err := hasher.Encode(hasher.Hash(encoded))
 	if err != nil {
 		return "", err
 	}
@@ -116,41 +100,6 @@ func encodeSecret(sec *v1.Secret) (string, error) {
 	return string(data), nil
 }
 
-// encodeHash extracts the first 40 bits of the hash from the hex string
-// (1 hex char represents 4 bits), and then maps vowels and vowel-like hex
-// characters to consonants to prevent bad words from being formed (the theory
-// is that no vowels makes it really hard to make bad words). Since the string
-// is hex, the only vowels it can contain are 'a' and 'e'.
-// We picked some arbitrary consonants to map to from the same character set as GenerateName.
-// See: https://github.com/kubernetes/apimachinery/blob/dc1f89aff9a7509782bde3b68824c8043a3e58cc/pkg/util/rand/rand.go#L75
-// If the hex string contains fewer than ten characters, returns an error.
-func encodeHash(hex string) (string, error) {
-	if len(hex) < 10 {
-		return "", fmt.Errorf("the hex string must contain at least 10 characters")
-	}
-	enc := []rune(hex[:10])
-	for i := range enc {
-		switch enc[i] {
-		case '0':
-			enc[i] = 'g'
-		case '1':
-			enc[i] = 'h'
-		case '3':
-			enc[i] = 'k'
-		case 'a':
-			enc[i] = 'm'
-		case 'e':
-			enc[i] = 't'
-		}
-	}
-	return string(enc), nil
-}
-
-// hash hashes `data` with sha256 and returns the hex string
-func hash(data string) string {
-	return fmt.Sprintf("%x", sha256.Sum256([]byte(data)))
-}
-
 func unstructuredToConfigmap(u unstructured.Unstructured) (*v1.ConfigMap, error) {
 	marshaled, err := json.Marshal(u.Object)
 	if err != nil {

k8sdeps/transformer/hash/kusthash_test.go

@@ -1,18 +1,5 @@
-/*
-Copyright 2017 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
 
 package hash
 
@@ -90,28 +77,6 @@ func TestSecretHash(t *testing.T) {
 	}
 }
 
-func TestArrayHash(t *testing.T) {
-	array1 := []string{"a", "b", "c"}
-	array2 := []string{"c", "b", "a"}
-	h1, err := SortArrayAndComputeHash(array1)
-	if err != nil {
-		t.Errorf("unexpected error %v", err)
-	}
-	if h1 == "" {
-		t.Errorf("failed to hash %v", array1)
-	}
-	h2, err := SortArrayAndComputeHash(array2)
-	if err != nil {
-		t.Errorf("unexpected error %v", err)
-	}
-	if h2 == "" {
-		t.Errorf("failed to hash %v", array2)
-	}
-	if h1 != h2 {
-		t.Errorf("hash is not consistent with reordered list: %s %s", h1, h2)
-	}
-}
-
 func TestEncodeConfigMap(t *testing.T) {
 	cases := []struct {
 		desc   string
@@ -178,15 +143,6 @@ func TestEncodeSecret(t *testing.T) {
 	}
 }
 
-func TestHash(t *testing.T) {
-	// hash the empty string to be sure that sha256 is being used
-	expect := "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
-	sum := hash("")
-	if expect != sum {
-		t.Errorf("expected hash %q but got %q", expect, sum)
-	}
-}
-
 // warn devs who change types that they might have to update a hash function
 // not perfect, as it only checks the number of top-level fields
 func TestTypeStability(t *testing.T) {

k8sdeps/transformer/inventory/transformer.go

@@ -5,9 +5,10 @@ package inventory
 
 import (
 	"fmt"
+
 	"sigs.k8s.io/kustomize/k8sdeps/kunstruct"
-	"sigs.k8s.io/kustomize/k8sdeps/transformer/hash"
 	"sigs.k8s.io/kustomize/pkg/gvk"
+	"sigs.k8s.io/kustomize/pkg/hasher"
 	"sigs.k8s.io/kustomize/pkg/ifc"
 	"sigs.k8s.io/kustomize/pkg/inventory"
 	"sigs.k8s.io/kustomize/pkg/resid"
@@ -68,7 +69,7 @@ func (tf *transformer) Transform(m resmap.ResMap) error {
 		invty.Current[item] = refs
 		keys = append(keys, item.String())
 	}
-	h, err := hash.SortArrayAndComputeHash(keys)
+	h, err := hasher.SortArrayAndComputeHash(keys)
 	if err != nil {
 		return err
 	}

pkg/hasher/hasher.go

@@ -0,0 +1,52 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package hasher
+
+import (
+	"crypto/sha256"
+	"encoding/json"
+	"fmt"
+	"sort"
+)
+
+// SortArrayAndComputeHash sorts a string array and
+// returns a hash for it
+func SortArrayAndComputeHash(s []string) (string, error) {
+	sort.Strings(s)
+	data, err := json.Marshal(s)
+	if err != nil {
+		return "", err
+	}
+	return Encode(Hash(string(data)))
+}
+
+// Copied from https://github.com/kubernetes/kubernetes
+// /blob/master/pkg/kubectl/util/hash/hash.go
+func Encode(hex string) (string, error) {
+	if len(hex) < 10 {
+		return "", fmt.Errorf(
+			"input length must be at least 10.")
+	}
+	enc := []rune(hex[:10])
+	for i := range enc {
+		switch enc[i] {
+		case '0':
+			enc[i] = 'g'
+		case '1':
+			enc[i] = 'h'
+		case '3':
+			enc[i] = 'k'
+		case 'a':
+			enc[i] = 'm'
+		case 'e':
+			enc[i] = 't'
+		}
+	}
+	return string(enc), nil
+}
+
+// Hash returns the hex form of the sha256 of the argument.
+func Hash(data string) string {
+	return fmt.Sprintf("%x", sha256.Sum256([]byte(data)))
+}

pkg/hasher/hasher_test.go

@@ -0,0 +1,41 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package hasher_test
+
+import (
+	"testing"
+
+	. "sigs.k8s.io/kustomize/pkg/hasher"
+)
+
+func TestSortArrayAndComputeHash(t *testing.T) {
+	array1 := []string{"a", "b", "c", "d"}
+	array2 := []string{"c", "b", "d", "a"}
+	h1, err := SortArrayAndComputeHash(array1)
+	if err != nil {
+		t.Errorf("unexpected error %v", err)
+	}
+	if h1 == "" {
+		t.Errorf("failed to hash %v", array1)
+	}
+	h2, err := SortArrayAndComputeHash(array2)
+	if err != nil {
+		t.Errorf("unexpected error %v", err)
+	}
+	if h2 == "" {
+		t.Errorf("failed to hash %v", array2)
+	}
+	if h1 != h2 {
+		t.Errorf("hash is not consistent with reordered list: %s %s", h1, h2)
+	}
+}
+
+func TestHash(t *testing.T) {
+	// hash the empty string to be sure that sha256 is being used
+	expect := "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+	sum := Hash("")
+	if expect != sum {
+		t.Errorf("expected hash %q but got %q", expect, sum)
+	}
+}