module MCollective::Util

Some basic utility helper methods useful to clients, agents, runner etc.

Public Class Methods

absolute_path?(path, separator=File::SEPARATOR, alt_separator=File::ALT_SEPARATOR) click to toggle source

we should really use Pathname#absolute? but it's not in all the ruby versions we support and it comes down to roughly this

# File lib/mcollective/util.rb, line 462
def self.absolute_path?(path, separator=File::SEPARATOR, alt_separator=File::ALT_SEPARATOR)
  if alt_separator
    path_matcher = /^([a-zA-Z]:){0,1}[#{Regexp.quote alt_separator}#{Regexp.quote separator}]/
  else
    path_matcher = /^#{Regexp.quote separator}/
  end

  !!path.match(path_matcher)
end
align_text(text, console_cols = nil, preamble = 5) click to toggle source

Returns an aligned_string of text relative to the size of the terminal window. If a line in the string exceeds the width of the terminal window the line will be chopped off at the whitespace chacter closest to the end of the line and prepended to the next line, keeping all indentation.

The terminal size is detected by default, but custom line widths can passed. All strings will also be left aligned with 5 whitespace characters by default.

# File lib/mcollective/util.rb, line 308
def self.align_text(text, console_cols = nil, preamble = 5)
  unless console_cols
    console_cols = terminal_dimensions[0]

    # if unknown size we default to the typical unix default
    console_cols = 80 if console_cols == 0
  end

  console_cols -= preamble

  # Return unaligned text if console window is too small
  return text if console_cols <= 0

  # If console is 0 this implies unknown so we assume the common
  # minimal unix configuration of 80 characters
  console_cols = 80 if console_cols <= 0

  text = text.split("\n")
  piece = ''
  whitespace = 0

  text.each_with_index do |line, i|
    whitespace = 0

    while whitespace < line.length && line[whitespace].chr == ' '
      whitespace += 1
    end

    # If the current line is empty, indent it so that a snippet
    # from the previous line is aligned correctly.
    if line == ""
      line = (" " * whitespace)
    end

    # If text was snipped from the previous line, prepend it to the
    # current line after any current indentation.
    if piece != ''
      # Reset whitespaces to 0 if there are more whitespaces than there are
      # console columns
      whitespace = 0 if whitespace >= console_cols

      # If the current line is empty and being prepended to, create a new
      # empty line in the text so that formatting is preserved.
      if text[i + 1] && line == (" " * whitespace)
        text.insert(i + 1, "")
      end

      # Add the snipped text to the current line
      line.insert(whitespace, "#{piece} ")
    end

    piece = ''

    # Compare the line length to the allowed line length.
    # If it exceeds it, snip the offending text from the line
    # and store it so that it can be prepended to the next line.
    if line.length > (console_cols + preamble)
      reverse = console_cols

      while line[reverse].chr != ' '
        reverse -= 1
      end

      piece = line.slice!(reverse, (line.length - 1)).lstrip
    end

    # If a snippet exists when all the columns in the text have been
    # updated, create a new line and append the snippet to it, using
    # the same left alignment as the last line in the text.
    if piece != '' && text[i+1].nil?
      text[i+1] = "#{' ' * (whitespace)}#{piece}"
      piece = ''
    end

    # Add the preamble to the line and add it to the text
    line = ((' ' * preamble) + line)
    text[i] = line
  end

  text.join("\n")
end
color(code) click to toggle source

Return color codes, if the config color= option is false just return a empty string

# File lib/mcollective/util.rb, line 268
def self.color(code)
  colorize = Config.instance.color

  colors = {:red => "",
            :green => "",
            :yellow => "",
            :cyan => "",
            :bold => "",
            :reset => ""}

  if colorize
    return colors[code] || ""
  else
    return ""
  end
end
colorize(code, msg) click to toggle source

Helper to return a string in specific color

# File lib/mcollective/util.rb, line 286
def self.colorize(code, msg)
  "%s%s%s" % [ color(code), msg, color(:reset) ]
end
command_in_path?(command) click to toggle source

Checks in PATH returns true if the command is found

# File lib/mcollective/util.rb, line 415
def self.command_in_path?(command)
  found = ENV["PATH"].split(File::PATH_SEPARATOR).map do |p|
    File.exist?(File.join(p, command))
  end

  found.include?(true)
end
config_file_for_user() click to toggle source

Picks a config file defaults to ~/.mcollective else /etc/mcollective/client.cfg

# File lib/mcollective/util.rb, line 146
def self.config_file_for_user
  # expand_path is pretty lame, it relies on HOME environment
  # which isnt't always there so just handling all exceptions
  # here as cant find reverting to default
  begin
    config = File.expand_path("~/.mcollective")

    unless File.readable?(config) && File.file?(config)
      if self.windows?
        config = File.join(self.windows_prefix, "etc", "client.cfg")
      else
        config = "/etc/mcollective/client.cfg"
      end
    end
  rescue Exception => e
    if self.windows?
      config = File.join(self.windows_prefix, "etc", "client.cfg")
    else
      config = "/etc/mcollective/client.cfg"
    end
  end

  return config
end
default_options() click to toggle source

Creates a standard options hash

# File lib/mcollective/util.rb, line 172
def self.default_options
  {:verbose           => false,
   :disctimeout       => nil,
   :timeout           => 5,
   :config            => config_file_for_user,
   :collective        => nil,
   :discovery_method  => nil,
   :discovery_options => Config.instance.default_discovery_options,
   :filter            => empty_filter}
end
empty_filter() click to toggle source

Creates an empty filter

# File lib/mcollective/util.rb, line 130
def self.empty_filter
  {"fact"     => [],
   "cf_class" => [],
   "agent"    => [],
   "identity" => [],
   "compound" => []}
end
empty_filter?(filter) click to toggle source

Checks if the passed in filter is an empty one

# File lib/mcollective/util.rb, line 125
def self.empty_filter?(filter)
  filter == empty_filter || filter == {}
end
get_fact(fact) click to toggle source

Gets the value of a specific fact, mostly just a duplicate of MCollective::Facts.get_fact but it kind of goes with the other classes here

# File lib/mcollective/util.rb, line 61
def self.get_fact(fact)
  Facts.get_fact(fact)
end
has_agent?(agent) click to toggle source

Finds out if this MCollective has an agent by the name passed

If the passed name starts with a / it's assumed to be regex and will use regex to match

# File lib/mcollective/util.rb, line 8
def self.has_agent?(agent)
  agent = Regexp.new(agent.gsub("\/", "")) if agent.match("^/")

  if agent.is_a?(Regexp)
    if Agents.agentlist.grep(agent).size > 0
      return true
    else
      return false
    end
  else
    return Agents.agentlist.include?(agent)
  end

  false
end
has_cf_class?(klass) click to toggle source

Checks if this node has a configuration management class by parsing the a text file with just a list of classes, recipes, roles etc. This is ala the classes.txt from puppet.

If the passed name starts with a / it's assumed to be regex and will use regex to match

# File lib/mcollective/util.rb, line 38
def self.has_cf_class?(klass)
  klass = Regexp.new(klass.gsub("\/", "")) if klass.match("^/")
  cfile = Config.instance.classesfile

  Log.debug("Looking for configuration management classes in #{cfile}")

  begin
    File.readlines(cfile).each do |k|
      if klass.is_a?(Regexp)
        return true if k.chomp.match(klass)
      else
        return true if k.chomp == klass
      end
    end
  rescue Exception => e
    Log.warn("Parsing classes file '#{cfile}' failed: #{e.class}: #{e}")
  end

  false
end
has_fact?(fact, value, operator) click to toggle source

Compares fact == value,

If the passed value starts with a / it's assumed to be regex and will use regex to match

# File lib/mcollective/util.rb, line 69
def self.has_fact?(fact, value, operator)

  Log.debug("Comparing #{fact} #{operator} #{value}")
  Log.debug("where :fact = '#{fact}', :operator = '#{operator}', :value = '#{value}'")

  fact = Facts[fact]
  return false if fact.nil?

  fact = fact.clone

  if operator == '=~'
    # to maintain backward compat we send the value
    # as /.../ which is what 1.0.x needed.  this strips
    # off the /'s wich is what we need here
    if value =~ /^\/(.+)\/$/
      value = $1
    end

    return true if fact.match(Regexp.new(value))

  elsif operator == "=="
    return true if fact == value

  elsif ['<=', '>=', '<', '>', '!='].include?(operator)
    # Yuk - need to type cast, but to_i and to_f are overzealous
    if value =~ /^[0-9]+$/ && fact =~ /^[0-9]+$/
      fact = Integer(fact)
      value = Integer(value)
    elsif value =~ /^[0-9]+.[0-9]+$/ && fact =~ /^[0-9]+.[0-9]+$/
      fact = Float(fact)
      value = Float(value)
    end

    return true if eval("fact #{operator} value")
  end

  false
end
has_identity?(identity) click to toggle source

Checks if the configured identity matches the one supplied

If the passed name starts with a / it's assumed to be regex and will use regex to match

# File lib/mcollective/util.rb, line 112
def self.has_identity?(identity)
  identity = Regexp.new(identity.gsub("\/", "")) if identity.match("^/")

  if identity.is_a?(Regexp)
    return Config.instance.identity.match(identity)
  else
    return true if Config.instance.identity == identity
  end

  false
end
loadclass(klass) click to toggle source

Wrapper around MCollective::PluginManager.loadclass

# File lib/mcollective/util.rb, line 222
def self.loadclass(klass)
  PluginManager.loadclass(klass)
end
make_subscriptions(agent, type, collective=nil) click to toggle source
# File lib/mcollective/util.rb, line 183
def self.make_subscriptions(agent, type, collective=nil)
  config = Config.instance

  raise("Unknown target type #{type}") unless [:broadcast, :directed, :reply].include?(type)

  if collective.nil?
    config.collectives.map do |c|
      {:agent => agent, :type => type, :collective => c}
    end
  else
    raise("Unknown collective '#{collective}' known collectives are '#{config.collectives.join ', '}'") unless config.collectives.include?(collective)

    [{:agent => agent, :type => type, :collective => collective}]
  end
end
mcollective_version() click to toggle source
# File lib/mcollective/util.rb, line 296
def self.mcollective_version
  MCollective::VERSION
end
parse_fact_string(fact) click to toggle source

Parse a fact filter string like foo=bar into the tuple hash thats needed

# File lib/mcollective/util.rb, line 227
def self.parse_fact_string(fact)
  if fact =~ /^([^ ]+?)[ ]*=>[ ]*(.+)/
    return {:fact => $1, :value => $2, :operator => '>=' }
  elsif fact =~ /^([^ ]+?)[ ]*=<[ ]*(.+)/
    return {:fact => $1, :value => $2, :operator => '<=' }
  elsif fact =~ /^([^ ]+?)[ ]*(<=|>=|<|>|!=|==|=~)[ ]*(.+)/
    return {:fact => $1, :value => $3, :operator => $2 }
  elsif fact =~ /^(.+?)[ ]*=[ ]*\/(.+)\/$/
    return {:fact => $1, :value => "/#{$2}/", :operator => '=~' }
  elsif fact =~ /^([^= ]+?)[ ]*=[ ]*(.+)/
    return {:fact => $1, :value => $2, :operator => '==' }
  else
    raise "Could not parse fact #{fact} it does not appear to be in a valid format"
  end
end
ruby_version() click to toggle source

Returns the current ruby version as per RUBY_VERSION, mostly doing this here to aid testing

# File lib/mcollective/util.rb, line 292
def self.ruby_version
  RUBY_VERSION
end
setup_windows_sleeper() click to toggle source

On windows ^c can't interrupt the VM if its blocking on IO, so this sets up a dummy thread that sleeps and this will have the end result of being interruptable at least once a second. This is a common pattern found in Rails etc

# File lib/mcollective/util.rb, line 28
def self.setup_windows_sleeper
  Thread.new { loop { sleep 1 } } if Util.windows?
end
shellescape(str) click to toggle source

Escapes a string so it's safe to use in system() or backticks

Taken from Shellwords#shellescape since it's only in a few ruby versions

# File lib/mcollective/util.rb, line 246
def self.shellescape(str)
  return "''" if str.empty?

  str = str.dup

  # Process as a single byte sequence because not all shell
  # implementations are multibyte aware.
  str.gsub!(/([^A-Za-z0-9_\-.,:\/@\n])/, "\\\\\\1")

  # A LF cannot be escaped with a backslash because a backslash + LF
  # combo is regarded as line continuation and simply ignored.
  str.gsub!(/\n/, "'\n'")

  return str
end
str_to_bool(val) click to toggle source

Converts a string into a boolean value Strings matching 1,y,yes,true or t will return TrueClass Any other value will return FalseClass

# File lib/mcollective/util.rb, line 475
def self.str_to_bool(val)
  clean_val = val.to_s.strip
  if clean_val =~ /^(1|yes|true|y|t)$/
    return  true
  elsif clean_val =~ /^(0|no|false|n|f)$/
    return false
  else
    raise("Cannot convert string value '#{clean_val}' into a boolean.")
  end
end
subscribe(targets) click to toggle source

Helper to subscribe to a topic on multiple collectives or just one

# File lib/mcollective/util.rb, line 200
def self.subscribe(targets)
  connection = PluginManager["connector_plugin"]

  targets = [targets].flatten

  targets.each do |target|
    connection.subscribe(target[:agent], target[:type], target[:collective])
  end
end
templatepath(template_file) click to toggle source

Looks up the template directory and returns its full path

# File lib/mcollective/util.rb, line 487
def self.templatepath(template_file)
  config_dir = File.dirname(Config.instance.configfile)
  template_path = File.join(config_dir, template_file)
  return template_path if File.exists?(template_path)

  template_path = File.join("/etc/mcollective", template_file)
  return template_path
end
terminal_dimensions(stdout = STDOUT, environment = ENV) click to toggle source

Figures out the columns and lines of the current tty

Returns [0, 0] if it can't figure it out or if you're not running on a tty

# File lib/mcollective/util.rb, line 394
def self.terminal_dimensions(stdout = STDOUT, environment = ENV)
  return [0, 0] unless stdout.tty?

  return [80, 40] if Util.windows?

  if environment["COLUMNS"] && environment["LINES"]
    return [environment["COLUMNS"].to_i, environment["LINES"].to_i]

  elsif environment["TERM"] && command_in_path?("tput")
    return [%xtput cols`.to_i, %xtput lines`.to_i]

  elsif command_in_path?('stty')
    return %xstty size`.scan(/\d+/).map {|s| s.to_i }
  else
    return [0, 0]
  end
rescue
  [0, 0]
end
unsubscribe(targets) click to toggle source

Helper to unsubscribe to a topic on multiple collectives or just one

# File lib/mcollective/util.rb, line 211
def self.unsubscribe(targets)
  connection = PluginManager["connector_plugin"]

  targets = [targets].flatten

  targets.each do |target|
    connection.unsubscribe(target[:agent], target[:type], target[:collective])
  end
end
versioncmp(version_a, version_b) click to toggle source

compare two software versions as commonly found in package versions.

returns 0 if a == b returns -1 if a < b returns 1 if a > b

Code originally from Puppet

# File lib/mcollective/util.rb, line 431
def self.versioncmp(version_a, version_b)
  vre = /[-.]|\d+|[^-.\d]+/
  ax = version_a.scan(vre)
  bx = version_b.scan(vre)

  while (ax.length>0 && bx.length>0)
    a = ax.shift
    b = bx.shift

    if( a == b )                 then next
    elsif (a == '-' && b == '-') then next
    elsif (a == '-')             then return -1
    elsif (b == '-')             then return 1
    elsif (a == '.' && b == '.') then next
    elsif (a == '.' )            then return -1
    elsif (b == '.' )            then return 1
    elsif (a =~ /^\d+$/ && b =~ /^\d+$/) then
      if( a =~ /^0/ or b =~ /^0/ ) then
        return a.to_s.upcase <=> b.to_s.upcase
      end
      return a.to_i <=> b.to_i
    else
      return a.upcase <=> b.upcase
    end
  end

  version_a <=> version_b;
end
windows?() click to toggle source
# File lib/mcollective/util.rb, line 262
def self.windows?
  !!(RbConfig::CONFIG['host_os'] =~ /mswin|win32|dos|mingw|cygwin/)
end
windows_prefix() click to toggle source

Returns the PuppetLabs mcollective path for windows

# File lib/mcollective/util.rb, line 139
def self.windows_prefix
  require 'win32/dir'
  prefix = File.join(Dir::COMMON_APPDATA, "PuppetLabs", "mcollective")
end