#!/usr/bin/perl
#
# @@@ START COPYRIGHT @@@
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
#
# @@@ END COPYRIGHT @@@
#

#
# Implements:
#   ssh -M "ConnectTimeout 1" -o "ConnectionAttempts 3" n028 hostinfo 2>&1
#
# Uses:
#   export MY_NODES=' -w n028 -w n044 -w n029 -w n045 -w n030 -w n031 -w n032 '
#   export SQ_MON_SSH_OPTIONS=' -o "ConnectTimeout 1" -o "ConnectionAttempts 3" '
#

my $node_context=lc(readpipe("echo \$NODE_LIST"));
my %node_hash=();
my $sq_mon_ssh_options=readpipe("echo -n \$SQ_MON_SSH_OPTIONS");
my $json=$ARGV[0];

&main();

sub main()
{
  #$node_context=~s/-w//ig;
  #print "node_context=${node_context}";
  chomp($node_context);
  my @nodes=split(' ',$node_context);
  foreach my $node(@nodes)
  {
     $check_flag=check_node_status($node);
  }
  print_node_status();
}

sub print_node_status()
{
    if ($json) 
    {
        $comma="";
        print "[";
        foreach my $node(sort keys %node_hash)
        {
           if($comma)
           {
             print ",";
           }
           my $status=$node_hash{$node}{"status"};
           print "{\"NODE\":\"${node}\",\"STATUS\":\"${status}\"}";
           $comma="1"
        }
        print "]";
    }
    else
    {
        foreach my $node(sort keys %node_hash)
        {
           my $status=$node_hash{$node}{"status"};
           print "${node} \[ ${status} \]\n";
        }
    }
}

sub check_node_status($)
{
    my $node_id, $node_status;
    my $check_node=shift;
    #print "node=${check_node}\n";
    my $command="ssh -M -q $sq_mon_ssh_options $check_node hostname 2>&1";
    #print "command=${command}\n";
    my $down_character="ssh:";
    #print "down_character=${down_character}\n";

    my @check_results=lc((readpipe($command)));

    foreach my $check_result(@check_results)
    {
        if($check_result =~ /^$check_node/)
        {
           #print "check_result=${check_result}\n";
           $node_id=$check_node;
           $node_status="UP";
        }
        elsif($check_result =~ /^$down_character/)
        {
           #print "check_result=${check_result}\n";
           $node_id=$check_node;
           $node_status="DOWN";
        }

        #print "${node_id} [ ${node_status} ]\n";
        $node_hash{$node_id}{"status"}=$node_status;
    }

    return 1;
}