# class MCollective::RPC::Helpers

Various utilities for the RPC system

### Public Class Methods

add_simplerpc_options(parser, options) click to toggle source

Add SimpleRPC common options

    # File lib/mcollective/rpc/helpers.rb, line 250
    def self.add_simplerpc_options(parser, options)
      parser.separator ""

      # add SimpleRPC specific options to all clients that use our library
      parser.on('--np', '--no-progress', 'Do not show the progress bar') do |v|
        options[:progress_bar] = false
      end

      parser.on('--one', '-1', 'Send request to only one discovered nodes') do |v|
        options[:mcollective_limit_targets] = 1
      end

      parser.on('--batch SIZE', Integer, 'Do requests in batches') do |v|
        options[:batch_size] = v
      end

      parser.on('--batch-sleep SECONDS', Float, 'Sleep time between batches') do |v|
        options[:batch_sleep_time] = v
      end

      parser.on('--limit-seed NUMBER', Integer, 'Seed value for deterministic random batching') do |v|
        options[:limit_seed] = v
      end

      parser.on('--limit-nodes COUNT', '--ln', '--limit', 'Send request to only a subset of nodes, can be a percentage') do |v|
        raise "Invalid limit specified: #{v} valid limits are /^\d+%*$/" unless v =~ /^\d+%*$/

        if v =~ /^\d+$/
          options[:mcollective_limit_targets] = v.to_i
        else
          options[:mcollective_limit_targets] = v
        end
      end

      parser.on('--json', '-j', 'Produce JSON output') do |v|
        options[:progress_bar] = false
        options[:output_format] = :json
      end

      parser.on('--display MODE', 'Influence how results are displayed. One of ok, all or failed') do |v|
        if v == "all"
          options[:force_display_mode] = :always
        else
          options[:force_display_mode] = v.intern
        end

        raise "--display has to be one of 'ok', 'all' or 'failed'" unless [:ok, :failed, :always].include?(options[:force_display_mode])
      end
    end

extract_hosts_from_array(hosts) click to toggle source

Given an array of something, make sure each is a string chomp off any new lines and return just the array of hosts

    # File lib/mcollective/rpc/helpers.rb, line 29
    def self.extract_hosts_from_array(hosts)
      [hosts].flatten.map do |host|
        raise "#{host} should be a string" unless host.is_a?(String)
        host.chomp
      end
    end

extract_hosts_from_json(json) click to toggle source

Parse JSON output as produced by printrpc and extract the “sender” of each rpc response

The simplist valid JSON based data would be:

[

    {"sender" => "example.com"},
    {"sender" => "another.com"}

]

    # File lib/mcollective/rpc/helpers.rb, line 14
    def self.extract_hosts_from_json(json)
      hosts = JSON.parse(json)

      raise "JSON hosts list is not an array" unless hosts.is_a?(Array)

      hosts.map do |host|
        raise "JSON host list is not an array of Hashes" unless host.is_a?(Hash)
        raise "JSON host list does not have senders in it" unless host.include?("sender")

        host["sender"]
      end.uniq
    end

old_rpcresults(result, flags = {}) click to toggle source

Backward compatible display block for results without a DDL

    # File lib/mcollective/rpc/helpers.rb, line 198
    def self.old_rpcresults(result, flags = {})
      result_text = ""

      if flags[:flatten]
        result.each do |r|
          if r[:statuscode] <= 1
            data = r[:data]

            unless data.is_a?(String)
              result_text << data.pretty_inspect
            else
              result_text << data
            end
          else
            result_text << r.pretty_inspect
          end
        end

        result_text << ""
      else
        [result].flatten.each do |r|

          if flags[:verbose]
            result_text << "%-40s: %s\n" % [r[:sender], r[:statusmsg]]

            if r[:statuscode] <= 1
              r[:data].pretty_inspect.split("\n").each {|m| result_text += "    #{m}"}
              result_text << "\n\n"
            elsif r[:statuscode] == 2
              # dont print anything, no useful data to display
              # past what was already shown
            elsif r[:statuscode] == 3
              # dont print anything, no useful data to display
              # past what was already shown
            elsif r[:statuscode] == 4
              # dont print anything, no useful data to display
              # past what was already shown
            else
              result_text << "    #{r[:statusmsg]}"
            end
          else
            unless r[:statuscode] == 0
              result_text << "%-40s %s\n" % [r[:sender], Util.colorize(:red, r[:statusmsg])]
            end
          end
        end
      end

      result_text << ""
    end

rpcresults(result, flags = {}) click to toggle source

Returns a blob of text representing the results in a standard way

It tries hard to do sane things so you often should not need to write your own display functions

If the agent you are getting results for has a DDL it will use the hints in there to do the right thing specifically it will look at the values of display in the DDL to choose when to show results

If you do not have a DDL you can pass these flags:

    printrpc exim.mailq, :flatten => true
    printrpc exim.mailq, :verbose => true

If you’ve asked it to flatten the result it will not print sender hostnames, it will just print the result as if it’s one huge result, handy for things like showing a combined mailq.

    # File lib/mcollective/rpc/helpers.rb, line 54
    def self.rpcresults(result, flags = {})
      flags = {:verbose => false, :flatten => false, :format => :console, :force_display_mode => false}.merge(flags)

      result_text = ""
      ddl = nil

      # if running in verbose mode, just use the old style print
      # no need for all the DDL helpers obfuscating the result
      if flags[:format] == :json
        if STDOUT.tty?
          result_text = JSON.pretty_generate(result)
        else
          result_text = result.to_json
        end
      else
        if flags[:verbose]
          result_text = old_rpcresults(result, flags)
        else
          [result].flatten.each do |r|
            begin
              ddl ||= DDL.new(r.agent).action_interface(r.action.to_s)

              sender = r[:sender]
              status = r[:statuscode]
              message = r[:statusmsg]
              result = r[:data]

              if flags[:force_display_mode]
                display = flags[:force_display_mode]
              else
                display = ddl[:display]
              end

              # appand the results only according to what the DDL says
              case display
                when :ok
                  if status == 0
                    result_text << text_for_result(sender, status, message, result, ddl)
                  end

                when :failed
                  if status > 0
                    result_text << text_for_result(sender, status, message, result, ddl)
                  end

                when :always
                  result_text << text_for_result(sender, status, message, result, ddl)

                when :flatten
                  result_text << text_for_flattened_result(status, result)

              end
            rescue Exception => e
              # no DDL so just do the old style print unchanged for
              # backward compat
              result_text = old_rpcresults(result, flags)
            end
          end
        end
      end

      result_text
    end

text_for_flattened_result(status, result) click to toggle source

Returns text representing a flattened result of only good data

    # File lib/mcollective/rpc/helpers.rb, line 185
    def self.text_for_flattened_result(status, result)
      result_text = ""

      if status <= 1
        unless result.is_a?(String)
          result_text << result.pretty_inspect
        else
          result_text << result
        end
      end
    end

text_for_result(sender, status, msg, result, ddl) click to toggle source

Return text representing a result

    # File lib/mcollective/rpc/helpers.rb, line 119
    def self.text_for_result(sender, status, msg, result, ddl)
      statusses = ["",
                   Util.colorize(:red, "Request Aborted"),
                   Util.colorize(:yellow, "Unknown Action"),
                   Util.colorize(:yellow, "Missing Request Data"),
                   Util.colorize(:yellow, "Invalid Request Data"),
                   Util.colorize(:red, "Unknown Request Status")]

      result_text = "%-40s %s\n" % [sender, statusses[status]]
      result_text << "   %s\n" % [Util.colorize(:yellow, msg)] unless msg == "OK"

      # only print good data, ignore data that results from failure
      if [0, 1].include?(status)
        if result.is_a?(Hash)
          # figure out the lengths of the display as strings, we'll use
          # it later to correctly justify the output
          lengths = result.keys.map do |k|
            begin
              ddl[:output][k][:display_as].size
            rescue
              k.to_s.size
            end
          end

          result.keys.sort_by{|k| k}.each do |k|
            # get all the output fields nicely lined up with a
            # 3 space front padding
            begin
              display_as = ddl[:output][k][:display_as]
            rescue
              display_as = k.to_s
            end

            display_length = display_as.size
            padding = lengths.max - display_length + 3
            result_text << " " * padding

            result_text << "#{display_as}:"

            if [String, Numeric].include?(result[k].class)
              lines = result[k].to_s.split("\n")

              if lines.empty?
                result_text << "\n"
              else
                lines.each_with_index do |line, i|
                  i == 0 ? padtxt = " " : padtxt = " " * (padding + display_length + 2)

                  result_text << "#{padtxt}#{line}\n"
                end
              end
            else
              padding = " " * (lengths.max + 5)
              result_text << " " << result[k].pretty_inspect.split("\n").join("\n" << padding) << "\n"
            end
          end
        else
          result_text << "\n\t" + result.pretty_inspect.split("\n").join("\n\t")
        end
      end

      result_text << "\n"
      result_text
    end