Class: Gather_temperature

Inherits:
Object
  • Object
show all
Defined in:
rlib/gather_temperature.rb

Overview

Container for snmp queries retrieving temperature readings from TDC rack nodes IMM's

Constant Summary

TEMPERATURE =

should have a trailing .1, but returns nothing if we do?

'SNMPv2-SMI::enterprises.2.3.51.3.1.1.2.1.3'

Instance Method Summary (collapse)

Constructor Details

- (Gather_temperature) initialize(racks, snmp_community)

Create a Gather_temperature instance

Parameters:

  • racks (Pan_racks) —

    collection of Pan_rack records, each holding an array of pan_host records

  • snmp_community (String) —

    SNMP read community for the rack node's IMMs.



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# File 'rlib/gather_temperature.rb', line 12

def initialize(racks, snmp_community)
  @results = {}
  @racks = racks.racks #racks in TDC Pan Pod, Hashed indexed by TDC rack designation
  @snmp_community = snmp_community
  walk
end

Instance Method Details

- (String, 0) get(manager, ifTable_columns)

SNMP query handler

Parameters:

  • manager (SNMP::Manager) —

    From an SNMP::Manager.open (or new)

Returns:

  • (String, 0) —

    Value from the SNMP query, or 0 if this fails



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# File 'rlib/gather_temperature.rb', line 46

def get(manager, ifTable_columns)
  manager.walk(ifTable_columns) do |row|
    row.each do |vb| 
      if vb.name.to_s.split('.')[-1] == '1' #Looking for the .1 to indicate the temperature OID.
        return vb.value #Temperature
      end
    end
  end
  return 0 #No temperature.
end

- (Fixnum, String) process_host(host_name, ipmi_ip)

SNMP query wrapper to fetch temperature

Parameters:

  • hostname (String) —

    Host name of the target node in the rack

  • ipmi_ip (String) —

    The host's IMM ip address, which we do use

Returns:

  • (Fixnum, String) —

    the temperature we fetched from the host (or 0, if we can't contact it)



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# File 'rlib/gather_temperature.rb', line 61

def process_host(host_name, ipmi_ip)
  if host_name == nil
    return 0 #No temperature
  else
    begin
      ifTable_columns = [ TEMPERATURE ] #should have a trailing .1, but returns nothing if we do?
      SNMP::Manager.open(:Host => ipmi_ip, :Community => "#{@snmp_community}", :Version => :SNMPv2c) do |manager|
        return get(manager, ifTable_columns) #The temperature
      end
    rescue SignalException => message
      $stderr.print "#{Signal} #{message}\n"
      exit -1
    rescue Exception => message
      $stderr.print "#{host_name} #{message}\n"
      return 0 #No temperature.
    end
  end
end

- (Object) to_json(file)

Generate json from the resulting SNMP queries

Parameters:

  • file (String) —

    File name to write json output to



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# File 'rlib/gather_temperature.rb', line 82

def to_json(file)
  File.open(file,"w") do |fd|
    fd.puts '{'
    fd.puts "\"datetime\": [\"#{Time.now.strftime('%Y-%m-%d %H:%M:%S')}\"],"
    @results.each do |result, values|
      fd.print "\"#{result}\": ["
      values.each_with_index do |v,i|
        if i != 0
          fd.print "#{v},"
        end
      end
      fd.puts "],"
    end
    fd.puts '}'
  end
end

- (Object) walk

Process each rack's hosts, fetching the Ambient temperature



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# File 'rlib/gather_temperature.rb', line 20

def walk
  @racks.each do |rack_name, rack| #for each rack in the Pan Pod
    @results[rack_name] = [0] #This is a filler for the First Array element. Rack U's use origin of 1. Arrays use an origin of 0.
    rack.hosts.each_with_index do |host, i| #For each U in the rack, we should have a Pan_host record
      if host == nil #Shouldn't be the case, as we filled in all U during the setup.
        $stderr.puts "Host[#{i}] == nil in Rack #{rack_name}"
        @results[rack_name] << 0
      elsif host.class != Pan_host
        $stderr.puts "Host[#{i}] not a Pan_host record: Rack #{rack_name}"
        @results[rack_name] << 0
      else 
        if i != 0 #No racks have U == 0, so we ignore these. 
          if host.rack_u != i #This isn't a new host, but a multi-U host, that we have already processed. (Assumes hosts labeled by lowest U)
            @results[rack_name] << @results[rack_name][host.rack_u] #Fill in host temperature from the base U of this host
          else
            @results[rack_name] << process_host(host.hostname, host.ipV4_m) #host is an array of values, which we expand into the params.
          end
        end
      end
    end
  end
end