Class: OstrichPoll::Validator

Inherits:
Object
  • Object
show all
Defined in:
lib/ostrichpoll/ostrich_validator.rb

Overview

this is a pretty weak and limiting definition of a validator, but it’s quick to develop and clear how to extend

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#exit_code ⇒ Object

Returns the value of attribute exit_code.



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 138

def exit_code
  @exit_code
end

#exit_message ⇒ Object

Returns the value of attribute exit_message.



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 139

def exit_message
  @exit_message
end

#host_instance ⇒ Object

Returns the value of attribute host_instance.



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 131

def host_instance
  @host_instance
end

#metric ⇒ Object

Returns the value of attribute metric.



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 133

def metric
  @metric
end

#missing ⇒ Object

Returns the value of attribute missing.



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 137

def missing
  @missing
end

#normal_range ⇒ Object

Returns the value of attribute normal_range.



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 136

def normal_range
  @normal_range
end

#rate ⇒ Object

Returns the value of attribute rate.



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 134

def rate
  @rate
end

#regex ⇒ Object

Returns the value of attribute regex.



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 135

def regex
  @regex
end

Instance Method Details

#check(value) ⇒ Object 



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 162

def check (value)
  Log.debug "#{host_instance.url} | Given: #{metric}=#{value}"

  if !value.is_a? Float
    value = Float(value) rescue nil
  end

  # error on missing value unless we ignore missing
  unless value
    unless missing == :ignore
      error_msg = "#{metric}: value missing"
      Log.warn "#{error_msg}, treating as error; exit code #{exit_code}"
      return ExitStatus.new(error_msg, exit_code)
    else
      Log.debug "#{host_instance.url} |   missing value, but set to ignore"
      # not an error, but you can't check anything else
      return nil
    end
  end

  # compute rate
  if rate
    timestamp, previous = host_instance.previous_reading(metric)

    if previous
      Log.debug "#{host_instance.url} |   last seen: #{previous} @ #{timestamp}"

      # change since last measure
      value -= previous

      # divide by seconds elapsed
      value /= Time.now.to_i - timestamp

      Log.debug "#{host_instance.url} |   computed rate: #{value}"

    else
      # let it pass
      Log.info "#{metric}: no previous reading for rate"
      return nil
    end
  end

  # ensure value is within normal range
  if normal_range
    Log.debug "#{host_instance.url} |   normal range: #{normal_range.inspect}"
    case normal_range.size
      when 1 # max
        hi = normal_range.first

      when 2 # min
        lo = normal_range.first
        hi = normal_range.last

      else
        # whatever, ignore
        # the yaml deserializer shouldn't let this happen
    end

    if lo && value < lo
      Log.warn "#{metric}: read value #{value} is below normal range minimum #{lo}; exit code #{exit_code}; exit message '#{exit_message}'"
      return ExitStatus.new(exit_message, exit_code)
    end

    if hi && value > hi
      Log.warn "#{metric}: read value #{value} is above normal range maximum #{hi}; exit code #{exit_code}; exit message '#{exit_message}'"
      return ExitStatus.new(exit_message, exit_code)
    end

    Log.debug "#{host_instance.url} |   within normal range"
  end

  nil
end

#init ⇒ Object 



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 141

def init
  @rate = false
  @regex = false
  @exit_code = 1
  @exit_message = ""
  @missing = :ignore
end

#verify! ⇒ Object 



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# File 'lib/ostrichpoll/ostrich_validator.rb', line 149

def verify!
  Log.warn "Invalid metric #{metric.inspect}" unless metric.is_a? String
  Log.warn "Invalid exit code: #{exit_code.inspect}" unless exit_code.is_a? Integer

  if exit_message
    Log.warn "Invalid exit message: #{exit_message.inspect}" unless exit_message.is_a? String
  end

  if normal_range
    Log.warn "Invalid normal range: #{normal_range.inspect}" unless normal_range.is_a? Array
  end
end