Update to use sha224 and base62 text.

pkg/commands/helpers/kubectl_auth.go

@@ -24,6 +24,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"math/big"
 	"os"
 	"os/user"
 	"path/filepath"
@@ -173,7 +174,11 @@ func cacheFilePath(kopsStateStore string, clusterName string) string {
 	b.WriteString(clusterName)
 	b.WriteByte(0)
 
-	hash := fmt.Sprintf("%x", sha256.Sum256(b.Bytes()))
+	var i big.Int
+	hb := sha256.Sum224(b.Bytes())
+	i.SetBytes(hb[:])
+
+	hash := i.Text(62)
 	return filepath.Join(homedir.HomeDir(), ".kube", "cache", "kops-authentication", hash)
 }
 

pkg/commands/helpers/kubectl_auth_test.go

@@ -38,7 +38,7 @@ func Test_cacheFilePath(t *testing.T) {
 	output1 := cacheFilePath(inputs[0].kopsStateStore, inputs[0].clusterName)
 	_, file := path.Split(output1)
 
-	if len(file) > 64 {
+	if len(file) > 38 {
 		t.Errorf("cacheFilePath() got %v, too long(%v)", output1, len(file))
 	}
 }