[node.sh] add -L to set logging verbosity level

Signed-off-by: Leo Chen <leo@harmony.one>

scripts/node.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-version="v1 20200507.0"
+version="v1 20200513.0"
 
 unset -v progname
 progname="${0##*/}"
@@ -188,6 +188,7 @@ options:
    -r address     start a pprof profiling server listening on the specified address
    -I             use statically linked Harmony binary (default: true)
    -R tracefile   enable p2p trace using tracefile (default: off)
+   -L log_level   logging verbosity: 0=silent, 1=error, 2=warn, 3=info, 4=debug, 5=detail (default: $log_level)
 
 examples:
 
@@ -239,7 +240,7 @@ BUCKET=pub.harmony.one
 OS=$(uname -s)
 
 unset start_clean loop run_as_root blspass do_not_download download_only network node_type shard_id download_harmony_db db_file_to_dl
-unset upgrade_rel public_rpc staking_mode pub_port multi_key blsfolder blacklist verify TRACEFILE minpeers max_bls_keys_per_node
+unset upgrade_rel public_rpc staking_mode pub_port multi_key blsfolder blacklist verify TRACEFILE minpeers max_bls_keys_per_node log_level
 start_clean=false
 loop=true
 run_as_root=true
@@ -260,12 +261,13 @@ static=true
 verify=false
 minpeers=6
 max_bls_keys_per_node=10
+log_level=3
 ${BLSKEYFILE=}
 ${TRACEFILE=}
 
 unset OPTIND OPTARG opt
 OPTIND=1
-while getopts :1chk:sSp:dDN:T:i:ba:U:PvVyzn:MAIB:r:Y:f:R:m: opt
+while getopts :1chk:sSp:dDN:T:i:ba:U:PvVyzn:MAIB:r:Y:f:R:m:L: opt
 do
    case "${opt}" in
    '?') usage "unrecognized option -${OPTARG}";;
@@ -302,6 +304,7 @@ do
    y) staking_mode=false;;
    A) archival=true;;
    R) TRACEFILE="${OPTARG}";;
+   L) log_level="${OPTARG}";;
    *) err 70 "unhandled option -${OPTARG}";;  # EX_SOFTWARE
    esac
 done
@@ -911,6 +914,7 @@ do
       -blacklist="${blacklist}"
       -min_peers="${minpeers}"
       -max_bls_keys_per_node="${max_bls_keys_per_node}"
+      -verbosity="${log_level}"
    )
    args+=(
       -is_archival="${archival}"