restructure startup & config logic

internal/randx/string.go

@@ -0,0 +1,14 @@
+package randx
+
+import (
+	"math/rand"
+)
+
+// String returns a random string with the given length
+func String(characters string, length int) string {
+	bytes := make([]byte, length)
+	for i := range bytes {
+		bytes[i] = characters[rand.Int63()%int64(len(characters))]
+	}
+	return string(bytes)
+}