Extra argument to specify metrics websocket + long attribute (#448)

* Extra argument to specify metrics websocket + long attribute

* Default testnet values

explorer/src/main.rs

@@ -14,15 +14,22 @@ mod websockets;
 // this specifies number of messages that can be held by the channel, not number of the clients.
 const BROADCAST_CAPACITY: usize = 10;
 const VALIDATOR_ARG: &str = "validator";
+const METRICS_ARG: &str = "metrics";
 
 fn parse_args<'a>() -> ArgMatches<'a> {
     App::new("Nym Explorer")
         .author("Nymtech")
         .arg(
             Arg::with_name(VALIDATOR_ARG)
-                .help("REST endpoint of the explorer will use to periodically grab topology and node status.")
+                .long(VALIDATOR_ARG)
+                .help("REST endpoint of the validator that explorer will use to periodically grab topology and node status.")
+                .takes_value(true)
+        )
+        .arg(
+            Arg::with_name(METRICS_ARG)
+                .long(METRICS_ARG)
+                .help("websocket endpoint of the metrics server explorer will subscribe to and broadcast to its clients")
                 .takes_value(true)
-                .required(true),
         )
         .get_matches()
 }
@@ -35,7 +42,13 @@ fn index() -> &'static str {
 #[tokio::main]
 async fn main() {
     let matches = parse_args();
-    let validator_base_url = matches.value_of(VALIDATOR_ARG).unwrap();
+    let validator_base_url = matches
+        .value_of(VALIDATOR_ARG)
+        .unwrap_or_else(|| "http://testnet-validator1.nymtech.net:8081");
+    let metrics_websocket_url = matches
+        .value_of(METRICS_ARG)
+        .unwrap_or_else(|| "wss://testnet-metrics.nymtech.net/ws")
+        .to_owned();
 
     let public_path = std::env::current_exe()
     .expect("Failed to evaluate current exe path")
@@ -55,7 +68,7 @@ async fn main() {
     let sender_clone = sender.clone();
 
     tokio::spawn(async move {
-        websockets::subscribe("wss://qa-metrics.nymtech.net/ws", sender).await;
+        websockets::subscribe(&*metrics_websocket_url, sender).await;
     });
 
     tokio::spawn(async move {