From c9ff6a9ab98e315ceb1f8c2911ce2accdd4c79d8 Mon Sep 17 00:00:00 2001
From: Ryan McKinley <ryantxu@gmail.com>
Date: Wed, 24 Jan 2024 11:27:46 -0800
Subject: [PATCH] Chore: Generate shorter UIDs (#79843)

---
 pkg/util/shortid_generator.go      | 36 +++++++++++++++++++++---------
 pkg/util/shortid_generator_test.go | 24 +++++++++++++++-----
 2 files changed, 45 insertions(+), 15 deletions(-)

diff --git a/pkg/util/shortid_generator.go b/pkg/util/shortid_generator.go
index eb841b7bba0..db216e622a6 100644
--- a/pkg/util/shortid_generator.go
+++ b/pkg/util/shortid_generator.go
@@ -8,6 +8,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/bwmarrin/snowflake"
 	"github.com/google/uuid"
 )
 
@@ -42,24 +43,39 @@ func IsShortUIDTooLong(uid string) bool {
 	return len(uid) > MaxUIDLength
 }
 
+var node *snowflake.Node
+
 // GenerateShortUID will generate a UUID that can also be a k8s name
 // it is guaranteed to have a character as the first letter
 // This UID will be a valid k8s name
 func GenerateShortUID() string {
 	mtx.Lock()
 	defer mtx.Unlock()
-	uid, err := uuid.NewRandom()
-	if err != nil {
-		// This should never happen... but this seems better than a panic
-		for i := range uid {
-			uid[i] = byte(uidrand.Intn(255))
+
+	if node == nil {
+		// ignoring the error happens when input outside 0-1023
+		node, _ = snowflake.NewNode(rand.Int63n(1024))
+	}
+
+	// Use UUIDs if snowflake failed (should be never)
+	if node == nil {
+		uid, err := uuid.NewRandom()
+		if err != nil {
+			// This should never happen... but this seems better than a panic
+			for i := range uid {
+				uid[i] = byte(uidrand.Intn(255))
+			}
 		}
+		uuid := uid.String()
+		if rune(uuid[0]) < rune('a') {
+			uuid = string(hexLetters[uidrand.Intn(len(hexLetters))]) + uuid[1:]
+		}
+		return uuid
 	}
-	uuid := uid.String()
-	if rune(uuid[0]) < rune('a') {
-		return string(hexLetters[uidrand.Intn(len(hexLetters))]) + uuid[1:]
-	}
-	return uuid
+
+	return string(hexLetters[uidrand.Intn(len(hexLetters))]) + // start with a letter
+		node.Generate().Base36() +
+		string(hexLetters[uidrand.Intn(len(hexLetters))]) // a bit more entropy
 }
 
 // ValidateUID checks the format and length of the string and returns error if it does not pass the condition
diff --git a/pkg/util/shortid_generator_test.go b/pkg/util/shortid_generator_test.go
index 010219244ae..6bc4bb05b5c 100644
--- a/pkg/util/shortid_generator_test.go
+++ b/pkg/util/shortid_generator_test.go
@@ -1,12 +1,13 @@
 package util
 
 import (
+	"fmt"
 	"sync"
 	"testing"
 
 	"cuelang.org/go/pkg/strings"
-	"github.com/google/uuid"
 	"github.com/stretchr/testify/require"
+	"github.com/teris-io/shortid"
 	"k8s.io/apimachinery/pkg/util/validation"
 )
 
@@ -48,14 +49,27 @@ func TestRandomUIDs(t *testing.T) {
 			t.Fatalf("created invalid name: %v", validation)
 		}
 
-		_, err := uuid.Parse(v)
-		require.NoError(t, err)
-
-		//fmt.Println(v)
+		//	fmt.Println(v)
 	}
 	// t.FailNow()
 }
 
+func TestCaseInsensitiveCollisionsUIDs(t *testing.T) {
+	history := make(map[string]bool, 0)
+	for i := 0; i < 100000; i++ {
+		v := GenerateShortUID()
+		if false {
+			v, _ = shortid.Generate() // collides in less then 500 iterations
+		}
+
+		lower := strings.ToLower(v)
+		_, exists := history[lower]
+		require.False(t, exists, fmt.Sprintf("already found: %s (index:%d)", v, i))
+
+		history[lower] = true
+	}
+}
+
 func TestIsShortUIDTooLong(t *testing.T) {
 	var tests = []struct {
 		name     string