Fix generate node name with less then 32 characters (#1596)

* fix generate node name with less then 32 characters

* refactor generate_node_name

substrate/core/cli/src/lib.rs

@@ -60,6 +60,8 @@ use lazy_static::lazy_static;
 
 use futures::Future;
 
+const MAX_NODE_NAME_LENGTH: usize = 32;
+
 /// Executable version. Used to pass version information from the root crate.
 pub struct VersionInfo {
 	/// Implemtation name.
@@ -91,6 +93,19 @@ fn get_chain_key(cli: &SharedParams) -> String {
 	}
 }
 
+fn generate_node_name() -> String {
+	let result = loop {
+		let node_name = Generator::with_naming(Name::Numbered).next().unwrap();
+		let count = node_name.chars().count();
+
+		if count < MAX_NODE_NAME_LENGTH {
+			break node_name
+		}
+	};
+	
+	result
+}
+
 fn load_spec<F, G>(cli: &SharedParams, factory: F) -> error::Result<ChainSpec<G>>
 	where G: RuntimeGenesis, F: FnOnce(&str) -> Result<Option<ChainSpec<G>>, String>,
 {
@@ -121,7 +136,6 @@ fn create_input_err<T: Into<String>>(msg: T) -> error::Error {
 
 /// Check whether a node name is considered as valid
 fn is_node_name_valid(_name: &str) -> Result<(), &str> {
-	const MAX_NODE_NAME_LENGTH: usize = 32;
 	let name = _name.to_string();
 	if name.chars().count() >= MAX_NODE_NAME_LENGTH {
 		return Err("Node name too long");
@@ -284,7 +298,7 @@ where
 	config.impl_version = version.version;
 
 	config.name = match cli.name {
-		None => Generator::with_naming(Name::Numbered).next().unwrap(),
+		None => generate_node_name(),
 		Some(name) => name,
 	};
 	match is_node_name_valid(&config.name) {