Remove GenesisConfig, add BeaconChainStartMethod

beacon_node/src/config.rs

@@ -2,7 +2,7 @@ use clap::ArgMatches;
 use client::{Bootstrapper, ClientConfig, Eth2Config};
 use eth2_config::{read_from_file, write_to_file};
 use rand::{distributions::Alphanumeric, Rng};
-use slog::{crit, info, Logger};
+use slog::{crit, info, warn, Logger};
 use std::fs;
 use std::path::PathBuf;
 
@@ -35,15 +35,16 @@ pub fn get_configs(matches: &ArgMatches, log: &Logger) -> Result<Config> {
                 // The bootstrap testnet method requires inserting a libp2p address into the
                 // network config.
                 ("bootstrap", Some(sub_matches)) => {
-                    let server = sub_matches
+                    let server: String = sub_matches
                         .value_of("server")
-                        .ok_or_else(|| "No bootstrap server specified".into())?;
+                        .ok_or_else(|| "No bootstrap server specified")?
+                        .to_string();
 
                     let bootstrapper = Bootstrapper::from_server_string(server.to_string())?;
 
-                    if let Some(server_multiaddr) =
-                        bootstrapper.best_effort_multiaddr(sub_matches.value_of("libp2p_port"))
-                    {
+                    if let Some(server_multiaddr) = bootstrapper.best_effort_multiaddr(
+                        parse_port_option(sub_matches.value_of("libp2p_port")),
+                    ) {
                         info!(
                             log,
                             "Estimated bootstrapper libp2p address";
@@ -83,6 +84,11 @@ pub fn get_configs(matches: &ArgMatches, log: &Logger) -> Result<Config> {
     builder.build()
 }
 
+/// Decodes an optional string into an optional u16.
+fn parse_port_option(o: Option<&str>) -> Option<u16> {
+    o.and_then(|s| s.parse::<u16>().ok())
+}
+
 /// Allows for building a set of configurations based upon `clap` arguments.
 struct ConfigBuilder<'a> {
     matches: &'a ArgMatches<'a>,

beacon_node/src/main.rs

@@ -227,7 +227,9 @@ fn main() {
                     .short("p")
                     .long("port")
                     .value_name("TCP_PORT")
-                    .help("A libp2p listen port used to peer with the bootstrap server"))
+                    .help("A libp2p listen port used to peer with the bootstrap server. This flag is useful \
+                           when port-fowarding is used: you may connect using a different port than \
+                           the one the server is immediately listening on."))
             )
             .subcommand(SubCommand::with_name("recent")
                 .about("Creates a new genesis state where the genesis time was at the previous \