Class: Sensu::Handler

Inherits:
Object
  • Object
show all
Includes:
Mixlib::CLI, Plugin::Utils
Defined in:
lib/sensu-handler.rb

Constant Summary collapse

@@autorun =

This works just like Plugin::CLI’s autorun.

self

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Plugin::Utils

#config_files, #load_config, #net_http_req_class, #read_event, #settings

Constructor Details

#initialize(argv = ARGV) ⇒ Handler

Returns a new instance of Handler.



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# File 'lib/sensu-handler.rb', line 16

def initialize(argv = ARGV)
  super()
  self.argv = parse_options(argv)
end

Instance Attribute Details

#argvObject

Returns the value of attribute argv.



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# File 'lib/sensu-handler.rb', line 14

def argv
  @argv
end

Class Method Details

.disable_autorunObject



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# File 'lib/sensu-handler.rb', line 48

def self.disable_autorun
  @@autorun = false
end

.method_added(name) ⇒ Object



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# File 'lib/sensu-handler.rb', line 41

def method_added(name)
  if name == :handle
    @@autorun = self
  end
end

Instance Method Details

#api_request(method, path) {|req| ... } ⇒ Object

Yields:

  • (req)


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# File 'lib/sensu-handler.rb', line 96

def api_request(method, path, &blk)
  if api_settings.nil?
    raise "api.json settings not found."
  end
  domain = api_settings['host'].start_with?('http') ? api_settings['host'] : 'http://' + api_settings['host']
  uri = URI("#{domain}:#{api_settings['port']}#{path}") 
  req = net_http_req_class(method).new(uri)
  if api_settings['user'] && api_settings['password']
    req.basic_auth(api_settings['user'], api_settings['password'])
  end
  yield(req) if block_given?
  res = Net::HTTP.start(uri.hostname, uri.port, :use_ssl => uri.scheme == 'https') do |http|
    http.request(req)
  end
  res
end

#api_settingsObject



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# File 'lib/sensu-handler.rb', line 82

def api_settings
  @api_settings ||= if ENV['SENSU_API_URL']
    uri = URI(ENV['SENSU_API_URL'])
    {
      'host' => uri.host,
      'port' => uri.port,
      'user' => uri.user,
      'password' => uri.password
    }
  else
    settings['api']
  end
end

#bail(msg) ⇒ Object



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# File 'lib/sensu-handler.rb', line 75

def bail(msg)
  client_name = @event['client']['name'] || 'error:no-client-name'
  check_name = @event['check']['name'] || 'error:no-check-name'
  puts "#{msg}: #{client_name}/#{check_name}"
  exit 0
end

#event_exists?(client, check) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'lib/sensu-handler.rb', line 169

def event_exists?(client, check)
  api_request(:GET, '/event/' + client + '/' + check).code == '200'
end

#event_summary(trim_at = 100) ⇒ Object

Helpers and filters.



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# File 'lib/sensu-handler.rb', line 63

def event_summary(trim_at=100)
  summary = @event['check']['notification'] || @event['check']['description']
  if summary.nil?
    source = @event['check']['source'] || @event['client']['name']
    event_context = [source, @event['check']['name']].join('/')
    output = @event['check']['output'].chomp
    output = output.length > trim_at ? output[0..trim_at] + '...' : output
    summary = [event_context, output].join(' : ')
  end
  summary
end

#filterObject

Filters exit the proccess if the event should not be handled. Implementation of the default filters is below.



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# File 'lib/sensu-handler.rb', line 30

def filter
  filter_disabled
  filter_repeated
  filter_silenced
  filter_dependencies
end

#filter_dependenciesObject



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# File 'lib/sensu-handler.rb', line 173

def filter_dependencies
  if @event['check'].has_key?('dependencies')
    if @event['check']['dependencies'].is_a?(Array)
      @event['check']['dependencies'].each do |dependency|
        begin
          Timeout.timeout(2) do
            check, client = dependency.split('/').reverse
            if event_exists?(client || @event['client']['name'], check)
              bail 'check dependency event exists'
            end
          end
        rescue Errno::ECONNREFUSED
          puts 'connection refused attempting to query the sensu api for an event'
        rescue Timeout::Error
          puts 'timed out while attempting to query the sensu api for an event'
        end
      end
    end
  end
end

#filter_disabledObject



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# File 'lib/sensu-handler.rb', line 113

def filter_disabled
  if @event['check']['alert'] == false
    bail 'alert disabled'
  end
end

#filter_repeatedObject



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# File 'lib/sensu-handler.rb', line 119

def filter_repeated
  defaults = {
    'occurrences' => 1,
    'interval' => 30,
    'refresh' => 1800
  }

  if settings['sensu_plugin'].is_a?(Hash)
    defaults.merge!(settings['sensu_plugin'])
  end

  occurrences = (@event['check']['occurrences'] || defaults['occurrences']).to_i
  interval = (@event['check']['interval'] || defaults['interval']).to_i
  refresh = (@event['check']['refresh'] || defaults['refresh']).to_i
  if @event['occurrences'] < occurrences
    bail 'not enough occurrences'
  end
  if @event['occurrences'] > occurrences && @event['action'] == 'create'
    number = refresh.fdiv(interval).to_i
    unless number == 0 || (@event['occurrences'] - occurrences) % number == 0
      bail 'only handling every ' + number.to_s + ' occurrences'
    end
  end
end

#filter_silencedObject



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# File 'lib/sensu-handler.rb', line 148

def filter_silenced
  stashes = [
    ['client', '/silence/' + @event['client']['name']],
    ['check', '/silence/' + @event['client']['name'] + '/' + @event['check']['name']],
    ['check', '/silence/all/' + @event['check']['name']]
  ]
  stashes.each do |(scope, path)|
    begin
      Timeout.timeout(5) do
        if stash_exists?(path)
          bail scope + ' alerts silenced'
        end
      end
    rescue Errno::ECONNREFUSED
      puts 'connection refused attempting to query the sensu api for a stash'
    rescue Timeout::Error
      puts 'timed out while attempting to query the sensu api for a stash'
    end
  end
end

#handleObject

Implementing classes should override this.



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# File 'lib/sensu-handler.rb', line 23

def handle
  puts 'ignoring event -- no handler defined'
end

#stash_exists?(path) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'lib/sensu-handler.rb', line 144

def stash_exists?(path)
  api_request(:GET, '/stash' + path).code == '200'
end