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 255
def self.add_simplerpc_options(parser, options)
  parser.separator ""
  parser.separator "RPC Options"

  # 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 203
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
              Log.warn("The display option :flatten is being deprecated and will be removed in the next minor release")
              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 190
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 120
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 status == 0
    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
    elsif status == 1
      # for status 1 we dont want to show half baked
      # data by default since the DDL will supply all the defaults
      # it just doesnt look right
    else
      result_text << "\n\t" + result.pretty_inspect.split("\n").join("\n\t")
    end
  end

  result_text << "\n"
  result_text
end