Move hashing code out of k8sdeps.

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)))
+}