integration-cli: seed rand in makeRandomString

Current uses of `makeRandomString` is to create really
long strings. In #10794, I used them to create nearly-unique
unix paths for the daemon. Although collions are harmless and
don't fail the tests, this prevents the same strings from being
created consistently in every run by seeding rand.Random.

Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
Upstream-commit: 00cd214afe46e79848e0f807bcdd19c20251cd2f
Component: engine

components/engine/integration-cli/utils.go

@@ -235,8 +235,9 @@ func makeRandomString(n int) string {
 	// make a really long string
 	letters := []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
 	b := make([]byte, n)
+	r := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
 	for i := range b {
-		b[i] = letters[rand.Intn(len(letters))]
+		b[i] = letters[r.Intn(len(letters))]
 	}
 	return string(b)
 }