ras-usage

#!/usr/bin/perl -w
#
# RAS-usage: determine the number of users (VPN clients) of the Juniper
#  SA-2500 remote access cluster. All members of the cluster know how many
#  users there are. The result is reported to Xymon using the clustername
#  as hostname.
#
# - Added test cluster, which is reported for each multi-node cluster
#   showing which node is active and which node(s) are passive. Based
#   on ideas of Tom Schmitt.
#
use strict ;
use POSIX qw/ strftime / ;              # Format time

#
# Installation constants.
#
my $XyDisp= $ENV{BBSERVERHOSTNAME} ;    # Name of monitor server
my $XySend= $ENV{BB} ;                  # Monitor interface program
my $FmtDate= '%Y.%m.%d %H:%M:%S' ;      # Default date format
   $FmtDate= $ENV{BBDATEFORMAT} if defined $ENV{BBDATEFORMAT} ;
my $TestName= 'usage' ;                 # Xymon test name

#
# Define the Juniper RAS clusters.
# Each entry describes one cluster. The key of an entry is name of the cluster.
# The value of an entry is a reference to a list of names of the physical nodes
# in the cluster. It is assumed that the DNS name is equal to the Xymon name in
# all these cases.
#
my %Ras= (
        <cluster>  => [ '<Node-0>', '<Node-1>' ],
   ) ;
#
# Define the number of available licenses per cluster.
#
my %MaxUsers= (                         # Number of available licenses
        <cluster>  => <Count>,
   ) ;

#
# Define the SNMP query command to determine the number of users. The OIDs
# of interest in subtree .1.3.6.1.4.1.12532. are:
#   2.0 - Number of Signed-In Web Users
#   3.0 - Number of Signed-In Mail Users
#   9.0 - the number of concurrent meeting users
#  12.0 - The Total number of Users Logged In for the IVE Node
#  13.0 - The Total number of Users Logged In for the Cluster
#
my $SnmpUser   = 'snmpget -c <ComString> -v 2c %s .1.3.6.1.4.1.12532.2.0' ;

#
# Define the SNMP query to determine which physical server holds the Virtual
# IP address of the cluster.
#
my $SnmpCluster= 'snmpget -c <ComString> -v 2c %s .1.3.6.1.2.1.4.20.1.1.%s' ;

#
# Variable allocation.
#
my $Now= strftime( $FmtDate, localtime ) ;      # Timestamp of tests
my $HostName ;                          # Xymon host name
my $Server ;                            # RAS node name
my $Cmd ;                               # Full blown snmpget command
my $Color ;                             # Test status
my $Users ;                             # Number of users
my %Cluster ;                           # Status of cluster nodes
my @Lines ;                             # Command output
my $Result ;                            # Test result

#
# Function UnpackIp transforms a binary formatted IPv4 address into a
# dotted decimal encoded string.
#
sub UnpackIp($) { return join('.',unpack('C4',$_[0])) } ;

#
# Main program.
# -------------
#
foreach $HostName ( keys %Ras ) {
  $Color = 'green' ;                    # Preset variables
  $Users = undef ;
  $Result= '' ;

 #
 # -A- Determine for each cluster the number of web users.
 #
 # The number of users is retrieved from the nodes. It was found that an
 # `snmpget` often fails if it is directed to the cluster service.
 #
  foreach $Server ( @{$Ras{$HostName}} ) {
    $Cmd= sprintf( $SnmpUser, $Server ) ;
    @Lines= `$Cmd` ;
    next                        unless defined $Lines[0] ;
    next                        unless $Lines[0]=~ m/ = Gauge32: (\d+)\s*$/ ;
    $Users= $1 ;                        # Concurrent web users
    last ;
  }  # of foreach

  #
  # Determine the test status and build the tail of the message.
  #
  unless ( defined $Users ) {
    $Color= 'red' ;
    $Result= "&$Color Cluster members are not accessible.\"\n" ;
  } else {
    if ( $Users > 0.9 * $MaxUsers{$HostName} ) {
      $Color = 'yellow' ;
      $Result= "&$Color High number of users&#58; $Users\n" ;
    }  # of if
    $Result.= "<!--\nusage = $Users\n-->" ;
  }  # of else
  
  #
  # Build the header of the message, and send it to Xymon.
  #
  $Result= "\"status $HostName.$TestName $Color $Now\n" .
         "Number of users of Remote Access Service\n\n" .
         $Result . "\"\n" ;
  `$XySend $XyDisp $Result` ;           # Inform Xymon

 #
 # -B- Determine the cluster status of each multi-node cluster.
 #     Test 'cluster' shows which node is active, and which are passive.
 #
  next                          unless @{$Ras{$HostName}} > 1 ;

  $Color  = 'green' ;
  $Result = '' ;
  %Cluster= () ;
  my $VirtualIp= UnpackIp( gethostbyname($HostName) ) ;

  foreach $Server ( @{$Ras{$HostName}} ) {
    $Cmd= sprintf( $SnmpCluster, $Server, $VirtualIp ) ;
    @Lines= `$Cmd` ;
    if ( defined $Lines[0] ) {
      if ( $Lines[0]=~ m/$VirtualIp$/ ) {
        $Cluster{$Server}= [ 'green', "$Server is the active node in cluster $HostName" ] ;
        $Result.= "&green $Server  active node\n" ;
      } elsif ( $Lines[0]=~ m/No Such Instance currently exists at this OID$/ ) {
        $Cluster{$Server}= [ 'clear', "$Server is a passive node in cluster $HostName" ] ;
        $Result.= "&green $Server  passive node\n" ;
      } else {
        $Color  = 'yellow'      unless $Color eq 'red' ;
        $Cluster{$Server}= [ 'yellow', "$Server has sent an unrecognised response:\n" .
                                       "  $Lines[0]" ] ;
        $Result.= "&yellow $Server  unrecognised response\n" ;
      }  # of else
    } else {
      $Color  = 'red' ;
      $Cluster{$Server}= [ $Color, "$Server has sent no response" ] ;
      $Result.= "&$Color $Server  no response\n" ;
    }  # of else
  }  # of foreach

  #
  # Report the status of all nodes together for the cluster service.
  #
  $Result= "\"status $HostName.cluster $Color $Now\n" .
         "Node status in this cluster\n\n" .
         $Result . "\"\n" ;
  `$XySend $XyDisp $Result` ;           # Inform Xymon

  #
  # Report the individual node status to each node individually.
  #
  foreach $Server ( keys %Cluster ) {
    $Color = $Cluster{$Server}[0] ;
    $Result= "\"status $Server.cluster $Color $Now\n" .
           $Cluster{$Server}[1] . "\"\n" ;
    `$XySend $XyDisp $Result` ;         # Inform Xymon
  }  # of foreach
}  # of foreach