Module: MCollective::Util

Defined in:
lib/mcollective/util.rb

Overview

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

Class Method Summary collapse

Class Method Details

.align_text(text, console_cols = nil, preamble = 5) ⇒ Object

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.



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# File 'lib/mcollective/util.rb', line 294

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) ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 254

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) ⇒ Object

Helper to return a string in specific color



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# File 'lib/mcollective/util.rb', line 272

def self.colorize(code, msg)
  "%s%s%s" % [ color(code), msg, color(:reset) ]
end

.command_in_path?(command) ⇒ Boolean

Checks in PATH returns true if the command is found

Returns:

  • (Boolean) 


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# File 'lib/mcollective/util.rb', line 401

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 ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 140

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)
      config = "/etc/mcollective/client.cfg"
    end
  rescue Exception => e
    config = "/etc/mcollective/client.cfg"
  end

  return config
end

.default_options ⇒ Object

Creates a standard options hash



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# File 'lib/mcollective/util.rb', line 158

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 ⇒ Object

Creates an empty filter



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# File 'lib/mcollective/util.rb', line 130

def self.empty_filter
  {"fact"     => [],
   "cf_class" => [],
   "agent"    => [],
   "identity" => [],
   "compound" => []}
end

.empty_filter?(filter) ⇒ Boolean

Checks if the passed in filter is an empty one

Returns:

  • (Boolean) 


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# File 'lib/mcollective/util.rb', line 125

def self.empty_filter?(filter)
  filter == empty_filter || filter == {}
end

.get_fact(fact) ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 61

def self.get_fact(fact)
  Facts.get_fact(fact)
end

.has_agent?(agent) ⇒ Boolean

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

Returns:

  • (Boolean) 


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# 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) ⇒ Boolean

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

Returns:

  • (Boolean) 


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# 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) ⇒ Boolean

Compares fact == value,

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

Returns:

  • (Boolean) 


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# 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) ⇒ Boolean

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

Returns:

  • (Boolean) 


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# 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) ⇒ Object

Wrapper around PluginManager.loadclass



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# File 'lib/mcollective/util.rb', line 208

def self.loadclass(klass)
  PluginManager.loadclass(klass)
end

.make_subscriptions(agent, type, collective = nil) ⇒ Object 



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# File 'lib/mcollective/util.rb', line 169

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 ⇒ Object 



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# File 'lib/mcollective/util.rb', line 282

def self.mcollective_version
  MCollective::VERSION
end

.parse_fact_string(fact) ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 213

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 ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 278

def self.ruby_version
  RUBY_VERSION
end

.setup_windows_sleeper ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 28

def self.setup_windows_sleeper
  Thread.new { loop { sleep 1 } } if Util.windows?
end

.shellescape(str) ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 232

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])/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

.subscribe(targets) ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 186

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

.terminal_dimensions(stdout = STDOUT, environment = ENV) ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 380

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 [`tput cols`.to_i, `tput lines`.to_i]

  elsif command_in_path?('stty')
    return `stty size`.scan(/\d+/).map {|s| s.to_i }
  else
    return [0, 0]
  end
rescue
  [0, 0]
end

.unsubscribe(targets) ⇒ Object

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



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# File 'lib/mcollective/util.rb', line 197

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) ⇒ Object

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 but refactored to a more ruby style that fits in better with this code base



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# File 'lib/mcollective/util.rb', line 418

def self.versioncmp(version_a, version_b)
  vre = /[-.]|\d+|[^-.\d]+/
  ax = version_a.scan(vre)
  bx = version_b.scan(vre)

  until ax.empty? || bx.empty?
    a = ax.shift
    b = bx.shift

    next      if a == b
    next      if a == '-' && b == '-'
    return -1 if a == '-'
    return 1  if b == '-'
    next      if a == '.' && b == '.'
    return -1 if a == '.'
    return 1  if b == '.'

    if a =~ /^[^0]\d+$/ && b =~ /^[^0]\d+$/
      return Integer(a) <=> Integer(b)
    else
      return a.upcase <=> b.upcase
    end
  end

  version_a <=> version_b
end

.windows? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mcollective/util.rb', line 248

def self.windows?
  !!(RbConfig::CONFIG['host_os'] =~ /mswin|win32|dos|mingw|cygwin/i)
end