Module MCollective::Util
In: lib/mcollective/util.rb

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

Methods

Public Class methods

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

[Source]

     # File lib/mcollective/util.rb, line 140
140:     def self.config_file_for_user
141:       # expand_path is pretty lame, it relies on HOME environment
142:       # which isnt't always there so just handling all exceptions
143:       # here as cant find reverting to default
144:       begin
145:         config = File.expand_path("~/.mcollective")
146: 
147:         unless File.readable?(config) && File.file?(config)
148:           config = "/etc/mcollective/client.cfg"
149:         end
150:       rescue Exception => e
151:         config = "/etc/mcollective/client.cfg"
152:       end
153: 
154:       return config
155:     end

Creates a standard options hash

[Source]

     # File lib/mcollective/util.rb, line 158
158:     def self.default_options
159:       {:verbose     => false,
160:         :disctimeout => 2,
161:         :timeout     => 5,
162:         :config      => config_file_for_user,
163:         :collective  => nil,
164:         :filter      => empty_filter}
165:     end

Creates an empty filter

[Source]

     # File lib/mcollective/util.rb, line 130
130:     def self.empty_filter
131:       {"fact"     => [],
132:         "cf_class" => [],
133:         "agent"    => [],
134:         "identity" => [],
135:         "compound" => []}
136:     end

Checks if the passed in filter is an empty one

[Source]

     # File lib/mcollective/util.rb, line 125
125:     def self.empty_filter?(filter)
126:       filter == empty_filter || filter == {}
127:     end

[Source]

     # File lib/mcollective/util.rb, line 250
250:     def self.eval_compound_statement(expression)
251:       if expression.values.first =~ /^\//
252:         return Util.has_cf_class?(expression.values.first)
253:       elsif expression.values.first =~ />=|<=|=|<|>/
254:         optype = expression.values.first.match(/>=|<=|=|<|>/)
255:         name, value = expression.values.first.split(optype[0])
256:         unless value.split("")[0] == "/"
257:           optype[0] == "=" ? optype = "==" : optype = optype[0]
258:         else
259:           optype = "=~"
260:         end
261: 
262:         return Util.has_fact?(name,value, optype).to_s
263:       else
264:         return Util.has_cf_class?(expression.values.first)
265:       end
266:     end

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

[Source]

    # File lib/mcollective/util.rb, line 61
61:     def self.get_fact(fact)
62:       Facts.get_fact(fact)
63:     end

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

[Source]

    # File lib/mcollective/util.rb, line 8
 8:     def self.has_agent?(agent)
 9:       agent = Regexp.new(agent.gsub("\/", "")) if agent.match("^/")
10: 
11:       if agent.is_a?(Regexp)
12:         if Agents.agentlist.grep(agent).size > 0
13:           return true
14:         else
15:           return false
16:         end
17:       else
18:         return Agents.agentlist.include?(agent)
19:       end
20: 
21:       false
22:     end

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

[Source]

    # File lib/mcollective/util.rb, line 38
38:     def self.has_cf_class?(klass)
39:       klass = Regexp.new(klass.gsub("\/", "")) if klass.match("^/")
40:       cfile = Config.instance.classesfile
41: 
42:       Log.debug("Looking for configuration management classes in #{cfile}")
43: 
44:       begin
45:         File.readlines(cfile).each do |k|
46:           if klass.is_a?(Regexp)
47:             return true if k.chomp.match(klass)
48:           else
49:             return true if k.chomp == klass
50:           end
51:         end
52:       rescue Exception => e
53:         Log.warn("Parsing classes file '#{cfile}' failed: #{e.class}: #{e}")
54:       end
55: 
56:       false
57:     end

Compares fact == value,

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

[Source]

     # File lib/mcollective/util.rb, line 69
 69:     def self.has_fact?(fact, value, operator)
 70: 
 71:       Log.debug("Comparing #{fact} #{operator} #{value}")
 72:       Log.debug("where :fact = '#{fact}', :operator = '#{operator}', :value = '#{value}'")
 73: 
 74:       fact = Facts[fact]
 75:       return false if fact.nil?
 76: 
 77:       fact = fact.clone
 78: 
 79:       if operator == '=~'
 80:         # to maintain backward compat we send the value
 81:         # as /.../ which is what 1.0.x needed.  this strips
 82:         # off the /'s wich is what we need here
 83:         if value =~ /^\/(.+)\/$/
 84:           value = $1
 85:         end
 86: 
 87:         return true if fact.match(Regexp.new(value))
 88: 
 89:       elsif operator == "=="
 90:         return true if fact == value
 91: 
 92:       elsif ['<=', '>=', '<', '>', '!='].include?(operator)
 93:         # Yuk - need to type cast, but to_i and to_f are overzealous
 94:         if value =~ /^[0-9]+$/ && fact =~ /^[0-9]+$/
 95:           fact = Integer(fact)
 96:           value = Integer(value)
 97:         elsif value =~ /^[0-9]+.[0-9]+$/ && fact =~ /^[0-9]+.[0-9]+$/
 98:           fact = Float(fact)
 99:           value = Float(value)
100:         end
101: 
102:         return true if eval("fact #{operator} value")
103:       end
104: 
105:       false
106:     end

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

[Source]

     # File lib/mcollective/util.rb, line 112
112:     def self.has_identity?(identity)
113:       identity = Regexp.new(identity.gsub("\/", "")) if identity.match("^/")
114: 
115:       if identity.is_a?(Regexp)
116:         return Config.instance.identity.match(identity)
117:       else
118:         return true if Config.instance.identity == identity
119:       end
120: 
121:       false
122:     end

Wrapper around PluginManager.loadclass

[Source]

     # File lib/mcollective/util.rb, line 206
206:     def self.loadclass(klass)
207:       PluginManager.loadclass(klass)
208:     end

[Source]

     # File lib/mcollective/util.rb, line 167
167:     def self.make_subscriptions(agent, type, collective=nil)
168:       config = Config.instance
169: 
170:       raise("Unknown target type #{type}") unless [:broadcast, :directed, :reply].include?(type)
171: 
172:       if collective.nil?
173:         config.collectives.map do |c|
174:           {:agent => agent, :type => type, :collective => c}
175:         end
176:       else
177:         raise("Unknown collective '#{collective}' known collectives are '#{config.collectives.join ', '}'") unless config.collectives.include?(collective)
178: 
179:         [{:agent => agent, :type => type, :collective => collective}]
180:       end
181:     end

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

[Source]

     # File lib/mcollective/util.rb, line 211
211:     def self.parse_fact_string(fact)
212:       if fact =~ /^([^ ]+?)[ ]*=>[ ]*(.+)/
213:         return {:fact => $1, :value => $2, :operator => '>=' }
214:       elsif fact =~ /^([^ ]+?)[ ]*=<[ ]*(.+)/
215:         return {:fact => $1, :value => $2, :operator => '<=' }
216:       elsif fact =~ /^([^ ]+?)[ ]*(<=|>=|<|>|!=|==|=~)[ ]*(.+)/
217:         return {:fact => $1, :value => $3, :operator => $2 }
218:       elsif fact =~ /^(.+?)[ ]*=[ ]*\/(.+)\/$/
219:         return {:fact => $1, :value => "/#{$2}/", :operator => '=~' }
220:       elsif fact =~ /^([^= ]+?)[ ]*=[ ]*(.+)/
221:         return {:fact => $1, :value => $2, :operator => '==' }
222:       else
223:         raise "Could not parse fact #{fact} it does not appear to be in a valid format"
224:       end
225:     end

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

[Source]

     # File lib/mcollective/util.rb, line 270
270:     def self.ruby_version
271:       RUBY_VERSION
272:     end

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

[Source]

    # File lib/mcollective/util.rb, line 28
28:     def self.setup_windows_sleeper
29:       Thread.new { loop { sleep 1 } } if Util.windows?
30:     end

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

[Source]

     # File lib/mcollective/util.rb, line 230
230:     def self.shellescape(str)
231:       return "''" if str.empty?
232: 
233:       str = str.dup
234: 
235:       # Process as a single byte sequence because not all shell
236:       # implementations are multibyte aware.
237:       str.gsub!(/([^A-Za-z0-9_\-.,:\/@\n])/n, "\\\\\\1")
238: 
239:       # A LF cannot be escaped with a backslash because a backslash + LF
240:       # combo is regarded as line continuation and simply ignored.
241:       str.gsub!(/\n/, "'\n'")
242: 
243:       return str
244:     end

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

[Source]

     # File lib/mcollective/util.rb, line 184
184:     def self.subscribe(targets)
185:       connection = PluginManager["connector_plugin"]
186: 
187:       targets = [targets].flatten
188: 
189:       targets.each do |target|
190:         connection.subscribe(target[:agent], target[:type], target[:collective])
191:       end
192:     end

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

[Source]

     # File lib/mcollective/util.rb, line 195
195:     def self.unsubscribe(targets)
196:       connection = PluginManager["connector_plugin"]
197: 
198:       targets = [targets].flatten
199: 
200:       targets.each do |target|
201:         connection.unsubscribe(target[:agent], target[:type], target[:collective])
202:       end
203:     end

[Source]

     # File lib/mcollective/util.rb, line 246
246:     def self.windows?
247:       !!(RbConfig::CONFIG['host_os'] =~ /mswin|win32|dos|mingw|cygwin/i)
248:     end

[Validate]