now possible to select ChainSpec by using CLI flag (lighthouse-252)

validator_client/src/main.rs

@@ -43,6 +43,15 @@ fn main() {
                 .help("Address to connect to BeaconNode.")
                 .takes_value(true),
         )
+        .arg(
+            Arg::with_name("spec")
+                .long("spec")
+                .value_name("spec")
+                .short("s")
+                .help("Configuration of Beacon Chain")
+                .takes_value(true)
+                .possible_values(&["foundation", "few_validators"]),
+        )
         .get_matches();
 
     let mut config = ClientConfig::default();
@@ -62,6 +71,17 @@ fn main() {
         }
     }
 
+    // TODO: Permit loading a custom spec from file.
+    // Custom spec
+    if let Some(spec_str) = matches.value_of("spec") {
+        match spec_str {
+            "foundation" => config.spec = ChainSpec::foundation(),
+            "few_validators" => config.spec = ChainSpec::few_validators(),
+            // Should be impossible
+            _ => error!(log, "Invalid spec defined"; "spec" => format!("{:?}", config.spec)),
+        };
+    }
+
     // Log configuration
     info!(log, "";
           "data_dir" => &config.data_dir.to_str(),
@@ -81,11 +101,8 @@ fn main() {
         Arc::new(ValidatorServiceClient::new(ch))
     };
 
-    // Ethereum
-    //
-    // TODO: Permit loading a custom spec from file.
-    // https://github.com/sigp/lighthouse/issues/160
-    let spec = Arc::new(ChainSpec::foundation());
+    // Spec
+    let spec = Arc::new(config.spec.clone());
 
     // Clock for determining the present slot.
     // TODO: this shouldn't be a static time, instead it should be pulled from the beacon node.