fix: use base36 as short name encoding

pkg/util/base36/base36.go

@@ -0,0 +1,168 @@
+package base36
+
+import (
+	"math/big"
+	"strings"
+)
+
+var (
+	base36 = []byte{
+		'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+		'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
+		'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
+		'u', 'v', 'w', 'x', 'y', 'z'}
+
+	//index = map[byte]int{
+	//	'0': 0, '1': 1, '2': 2, '3': 3, '4': 4,
+	//	'5': 5, '6': 6, '7': 7, '8': 8, '9': 9,
+	//	'A': 10, 'B': 11, 'C': 12, 'D': 13, 'E': 14,
+	//	'F': 15, 'G': 16, 'H': 17, 'I': 18, 'J': 19,
+	//	'K': 20, 'L': 21, 'M': 22, 'N': 23, 'O': 24,
+	//	'P': 25, 'Q': 26, 'R': 27, 'S': 28, 'T': 29,
+	//	'U': 30, 'V': 31, 'W': 32, 'X': 33, 'Y': 34,
+	//	'Z': 35,
+	//	'a': 10, 'b': 11, 'c': 12, 'd': 13, 'e': 14,
+	//	'f': 15, 'g': 16, 'h': 17, 'i': 18, 'j': 19,
+	//	'k': 20, 'l': 21, 'm': 22, 'n': 23, 'o': 24,
+	//	'p': 25, 'q': 26, 'r': 27, 's': 28, 't': 29,
+	//	'u': 30, 'v': 31, 'w': 32, 'x': 33, 'y': 34,
+	//	'z': 35,
+	//}
+	uint8Index = []uint64{
+		0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 1, 2,
+		3, 4, 5, 6, 7, 8, 9, 0, 0, 0,
+		0, 0, 0, 0, 10, 11, 12, 13, 14,
+		15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
+		25, 26, 27, 28, 29, 30, 31, 32, 33, 34,
+		35, 0, 0, 0, 0, 0, 0, 10, 11, 12, 13,
+		14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
+		24, 25, 26, 27, 28, 29, 30, 31, 32, 33,
+		34, 35, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, // 256
+	}
+	pow36Index = []uint64{
+		1, 36, 1296, 46656, 1679616, 60466176,
+		2176782336, 78364164096, 2821109907456,
+		101559956668416, 3656158440062976,
+		131621703842267136, 4738381338321616896,
+		9223372036854775808,
+	}
+)
+
+// Encode encodes a number to base36.
+func Encode(value uint64) string {
+	var res [16]byte
+	var i int
+	for i = len(res) - 1; ; i-- {
+		res[i] = base36[value%36]
+		value /= 36
+		if value == 0 {
+			break
+		}
+	}
+
+	return string(res[i:])
+}
+
+// Decode decodes a base36-encoded string.
+func Decode(s string) uint64 {
+	if len(s) > 13 {
+		s = s[:12]
+	}
+	res := uint64(0)
+	l := len(s) - 1
+	for idx := 0; idx < len(s); idx++ {
+		c := s[l-idx]
+		res += uint8Index[c] * pow36Index[idx]
+	}
+	return res
+}
+
+var bigRadix = big.NewInt(36)
+var bigZero = big.NewInt(0)
+
+// EncodeBytesAsBytes encodes a byte slice to base36.
+func EncodeBytesAsBytes(b []byte) []byte {
+	x := new(big.Int)
+	x.SetBytes(b)
+
+	answer := make([]byte, 0, len(b)*136/100)
+	for x.Cmp(bigZero) > 0 {
+		mod := new(big.Int)
+		x.DivMod(x, bigRadix, mod)
+		answer = append(answer, base36[mod.Int64()])
+	}
+
+	// leading zero bytes
+	for _, i := range b {
+		if i != 0 {
+			break
+		}
+		answer = append(answer, base36[0])
+	}
+
+	// reverse
+	alen := len(answer)
+	for i := 0; i < alen/2; i++ {
+		answer[i], answer[alen-1-i] = answer[alen-1-i], answer[i]
+	}
+
+	return answer
+}
+
+// EncodeBytes encodes a byte slice to base36 string.
+func EncodeBytes(b []byte) string {
+	return string(EncodeBytesAsBytes(b))
+}
+
+// DecodeToBytes decodes a base36 string to a byte slice, using alphabet.
+func DecodeToBytes(b string) []byte {
+	b = strings.ToUpper(b)
+	alphabet := string(base36)
+	answer := big.NewInt(0)
+	j := big.NewInt(1)
+
+	for i := len(b) - 1; i >= 0; i-- {
+		tmp := strings.IndexAny(alphabet, string(b[i]))
+		if tmp == -1 {
+			return []byte("")
+		}
+		idx := big.NewInt(int64(tmp))
+		tmp1 := big.NewInt(0)
+		tmp1.Mul(j, idx)
+
+		answer.Add(answer, tmp1)
+		j.Mul(j, bigRadix)
+	}
+
+	tmpval := answer.Bytes()
+
+	var numZeros int
+	for numZeros = 0; numZeros < len(b); numZeros++ {
+		if b[numZeros] != alphabet[0] {
+			break
+		}
+	}
+	flen := numZeros + len(tmpval)
+	val := make([]byte, flen)
+	copy(val[numZeros:], tmpval)
+
+	return val
+}

pkg/util/translate/single_namespace.go

@@ -6,6 +6,7 @@ import (
 	"regexp"
 	"strings"
 
+	"github.com/loft-sh/vcluster/pkg/util/base36"
 	"k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -40,8 +41,9 @@ func (s *singleNamespace) PhysicalNameShort(name, namespace string) string {
 		return ""
 	}
 
+	// we use base36 to avoid as much conflicts as possible
 	digest := sha256.Sum256([]byte(strings.Join([]string{name, "x", namespace, "x", VClusterName}, "-")))
-	return hex.EncodeToString(digest[0:])[0:8]
+	return base36.EncodeBytes(digest[:])[0:10]
 }
 
 func SingleNamespacePhysicalName(name, namespace, suffix string) string {