Create a local testnet (#2614)

The testnet will be on the local computer and have 1 eth1 node,
4 beacon nodes, 1 validator with 20 vc's.

scripts/local_testnet/beacon_node.sh

@@ -1,25 +1,54 @@
 #!/usr/bin/env bash
 
 #
-# Starts a beacon node based upon a genesis state created by
-# `./setup.sh`.
+# Starts a beacon node based upon a genesis state created by `./setup.sh`.
 #
-# Usage: ./beacon_node.sh <DATADIR> <NETWORK-PORT> <HTTP-PORT> <OPTIONAL-DEBUG-LEVEL>
 
 source ./vars.env
 
-DEBUG_LEVEL=${4:-info}
+SUBSCRIBE_ALL_SUBNETS=
+DEBUG_LEVEL=${DEBUG_LEVEL:-info}
+
+# Get options
+while getopts "d:sh" flag; do
+  case "${flag}" in
+    d) DEBUG_LEVEL=${OPTARG};;
+    s) SUBSCRIBE_ALL_SUBNETS="--subscribe-all-subnets";;
+    h)
+       echo "Start a beacon node"
+       echo
+       echo "usage: $0 <Options> <DATADIR> <NETWORK-PORT> <HTTP-PORT>"
+       echo
+       echo "Options:"
+       echo "   -s: pass --subscribe-all-subnets to 'lighthouse bn ...', default is not passed"
+       echo "   -d: DEBUG_LEVEL, default info"
+       echo "   -h: this help"
+       echo
+       echo "Positional arguments:"
+       echo "  DATADIR       Value for --datadir parameter"
+       echo "  NETWORK-PORT  Value for --enr-udp-port, --enr-tcp-port and --port"
+       echo "  HTTP-PORT     Value for --http-port"
+       exit
+       ;;
+  esac
+done
+
+# Get positional arguments
+data_dir=${@:$OPTIND+0:1}
+network_port=${@:$OPTIND+1:1}
+http_port=${@:$OPTIND+2:1}
 
 exec lighthouse \
 	--debug-level $DEBUG_LEVEL \
 	bn \
-	--datadir $1 \
+	$SUBSCRIBE_ALL_SUBNETS \
+	--datadir $data_dir \
 	--testnet-dir $TESTNET_DIR \
 	--staking \
 	--enr-address 127.0.0.1 \
-	--enr-udp-port $2 \
-	--enr-tcp-port $2 \
-	--port $2 \
-	--http-port $3 \
+	--enr-udp-port $network_port \
+	--enr-tcp-port $network_port \
+	--port $network_port \
+	--http-port $http_port \
 	--disable-packet-filter \
-	--target-peers $((NODE_COUNT - 1))
+	--target-peers $((BN_COUNT - 1))