Class: ScoutAgent::Assignment::Queue

Inherits:
ScoutAgent::Assignment show all
Defined in:
lib/scout_agent/assignment/queue.rb

Overview

Invoke with:

scout_agent q ID_OR_TYPE <<< '{"fields": "in JSON"}'

or:

ruby -e 'print Marshal.dump(:fields => "in Ruby")' | \
scout_agent q ID_OR_TYPE

This command queues some data from an external source for a plugin. The plugin to receive the message is given by ID in ID_OR_TYPE. That plugin will be able to collect this data during its next run.

Alternately, this command can be used to send a complete report, alert, error, or hint directly to the server (with the next check-in). When using as such, ID_OR_TYPE must be one of those types and the fields must be a Hash (object in JSON terminology) that includes the key “plugin_id” associated with an ID value for the reporting plugin.

If you prefer, you can pass Marshal data from Ruby for the fields instead of JSON.

Constant Summary collapse

ERRORS =

A list of errors that can be sent to the user when attempting to queue a message. The index of the message plus one is also the exit status for that error.

[ [ :missing_db,
"Queue database could not be loaded." ],
                 [ :missing_id,
"You must pass a mission ID or delivery type." ],
                 [ :invalid_id,
"You must pass a mission ID or " +
"'report', 'hint', 'alert', or 'error'." ],
                 [ :missing_fields,
"You must provide fields to queue." ],
                 [ :invalid_fields,
"You must pass valid JSON or Marshal data for the fields." ],
                 [ :invalid_report_fields,
"Field data must be a Hash to pass to the server." ],
                 [ :missing_plugin_id_field,
"A plugin_id field is required by the server." ],
                 [ :invalid_plugin_id_field,
"The plugin_id field must be a positive integer." ],
                 [ :failed_to_queue_message,
"Your message could not be queued at this time." ] ]

Instance Attribute Summary

Attributes inherited from ScoutAgent::Assignment

#group, #other_args, #switches, #user

Instance Method Summary collapse

Methods inherited from ScoutAgent::Assignment

choose_group, choose_user, #initialize, plan, #prepare_and_execute

Methods included from Tracked

#clear_status, #force_status_database_reload, #status, #status_database, #status_log

Constructor Details

This class inherits a constructor from ScoutAgent::Assignment

Instance Method Details

#execute ⇒ Object

Runs the queue command.



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# File 'lib/scout_agent/assignment/queue.rb', line 59

def execute
  # prepare the log
  log = ScoutAgent.prepare_wire_tap(:queue, :skip_stdout)

  # record our status and set removal at_exit()
  status_database(log)
  status("Queuing message", :queue)
  at_my_exit do
    clear_status(:queue)
  end
  
  # load the queue database
  unless db = Database.load(:queue, log)
    abort_with_error(:missing_db)
  end
  
  # ensure id or type is valid
  log.info("Validating message for queuing.")
  unless id = Array(other_args).shift
    abort_with_error(:missing_id)
  end
  unless id =~ /\A(?:report|hint|alert|error|\d*[1-9])\z/
    abort_with_error(:invalid_id)
  end
  
  # read field data and parse JSON
  fields = ARGF.read unless ARGV.empty? and not $stdin.ready?
  if fields.nil? or fields.empty?
    abort_with_error(:missing_fields)
  end
  bytes = fields.size
  begin
    if ["{", "["].include? fields[0, 1]  # it's JSON
      fields = JSON.parse(fields)
    else                                 # it's Marshal
      fields = Marshal.load(fields)
      if fields.is_a? Hash               # Stringify Hash keys
        (fields.keys - fields.keys.grep(String)).each do |key|
          fields[key.to_s] = fields.delete(key)
        end
      end
    end
  rescue Exception
    abort_with_error(:invalid_fields)
  end
  
  # ensure we have a valid plugin_id, if needed
  if %w[report hint alert error].include? id
    unless fields.is_a? Hash
      abort_with_error(:invalid_report_fields)
    end
    unless fields.include? "plugin_id"
      abort_with_error(:missing_plugin_id_field)
    end
    unless fields["plugin_id"].to_s =~ /\A\d*[1-9]\z/
      abort_with_error(:invalid_plugin_id_field)
    end
    log.info("Message is a valid #{id} (#{bytes} bytes).")
  else
    log.info("Message is valid (#{bytes} bytes).")
  end
  
  # queue the message
  log.info("Queuing message.")
  unless db.enqueue(id, fields)
    abort_with_error(:failed_to_queue_message)
  end
  
  # maintain the queue database
  db.maintain
  status_database.maintain
  # clean out old logs
  ScoutAgent.remove_old_log_files(log)
  
  log.info("Messages queued successfully.")
end