Class MCollective::RPC::Helpers
In: lib/mcollective/rpc/helpers.rb
Parent: Object

Various utilities for the RPC system

Methods

Public Class methods

Add SimpleRPC common options

[Source]

     # File lib/mcollective/rpc/helpers.rb, line 278
278:       def self.add_simplerpc_options(parser, options)
279:         parser.separator ""
280: 
281:         # add SimpleRPC specific options to all clients that use our library
282:         parser.on('--np', '--no-progress', 'Do not show the progress bar') do |v|
283:           options[:progress_bar] = false
284:         end
285: 
286:         parser.on('--one', '-1', 'Send request to only one discovered nodes') do |v|
287:           options[:mcollective_limit_targets] = 1
288:         end
289: 
290:         parser.on('--batch SIZE', Integer, 'Do requests in batches') do |v|
291:           options[:batch_size] = v
292:         end
293: 
294:         parser.on('--batch-sleep SECONDS', Float, 'Sleep time between batches') do |v|
295:           options[:batch_sleep_time] = v
296:         end
297: 
298:         parser.on('--limit-nodes COUNT', '--ln', 'Send request to only a subset of nodes, can be a percentage') do |v|
299:           raise "Invalid limit specified: #{v} valid limits are /^\d+%*$/" unless v =~ /^\d+%*$/
300: 
301:           if v =~ /^\d+$/
302:             options[:mcollective_limit_targets] = v.to_i
303:           else
304:             options[:mcollective_limit_targets] = v
305:           end
306:         end
307: 
308:         parser.on('--json', '-j', 'Produce JSON output') do |v|
309:           options[:progress_bar] = false
310:           options[:output_format] = :json
311:         end
312:       end

Checks in PATH returns true if the command is found

[Source]

    # File lib/mcollective/rpc/helpers.rb, line 6
 6:       def self.command_in_path?(command)
 7:         found = ENV["PATH"].split(File::PATH_SEPARATOR).map do |p|
 8:           File.exist?(File.join(p, command))
 9:         end
10: 
11:         found.include?(true)
12:       end

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

[Source]

    # File lib/mcollective/rpc/helpers.rb, line 38
38:       def self.extract_hosts_from_array(hosts)
39:         [hosts].flatten.map do |host|
40:           raise "#{host} should be a string" unless host.is_a?(String)
41:           host.chomp
42:         end
43:       end

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"}

]

[Source]

    # File lib/mcollective/rpc/helpers.rb, line 23
23:       def self.extract_hosts_from_json(json)
24:         hosts = JSON.parse(json)
25: 
26:         raise "JSON hosts list is not an array" unless hosts.is_a?(Array)
27: 
28:         hosts.map do |host|
29:           raise "JSON host list is not an array of Hashes" unless host.is_a?(Hash)
30:           raise "JSON host list does not have senders in it" unless host.include?("sender")
31: 
32:           host["sender"]
33:         end.uniq
34:       end

Backward compatible display block for results without a DDL

[Source]

     # File lib/mcollective/rpc/helpers.rb, line 226
226:       def self.old_rpcresults(result, flags = {})
227:         result_text = ""
228: 
229:         if flags[:flatten]
230:           result.each do |r|
231:             if r[:statuscode] <= 1
232:               data = r[:data]
233: 
234:               unless data.is_a?(String)
235:                 result_text << data.pretty_inspect
236:               else
237:                 result_text << data
238:               end
239:             else
240:               result_text << r.pretty_inspect
241:             end
242:           end
243: 
244:           result_text << ""
245:         else
246:           [result].flatten.each do |r|
247: 
248:             if flags[:verbose]
249:               result_text << "%-40s: %s\n" % [r[:sender], r[:statusmsg]]
250: 
251:               if r[:statuscode] <= 1
252:                 r[:data].pretty_inspect.split("\n").each {|m| result_text += "    #{m}"}
253:                 result_text << "\n\n"
254:               elsif r[:statuscode] == 2
255:                 # dont print anything, no useful data to display
256:                 # past what was already shown
257:               elsif r[:statuscode] == 3
258:                 # dont print anything, no useful data to display
259:                 # past what was already shown
260:               elsif r[:statuscode] == 4
261:                 # dont print anything, no useful data to display
262:                 # past what was already shown
263:               else
264:                 result_text << "    #{r[:statusmsg]}"
265:               end
266:             else
267:               unless r[:statuscode] == 0
268:                 result_text << "%-40s %s\n" % [r[:sender], Util.colorize(:red, r[:statusmsg])]
269:               end
270:             end
271:           end
272:         end
273: 
274:         result_text << ""
275:       end

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.

[Source]

     # File lib/mcollective/rpc/helpers.rb, line 87
 87:       def self.rpcresults(result, flags = {})
 88:         flags = {:verbose => false, :flatten => false, :format => :console}.merge(flags)
 89: 
 90:         result_text = ""
 91:         ddl = nil
 92: 
 93:         # if running in verbose mode, just use the old style print
 94:         # no need for all the DDL helpers obfuscating the result
 95:         if flags[:format] == :json
 96:           if STDOUT.tty?
 97:             result_text = JSON.pretty_generate(result)
 98:           else
 99:             result_text = result.to_json
100:           end
101:         else
102:           if flags[:verbose]
103:             result_text = old_rpcresults(result, flags)
104:           else
105:             [result].flatten.each do |r|
106:               begin
107:                 ddl ||= DDL.new(r.agent).action_interface(r.action.to_s)
108: 
109:                 sender = r[:sender]
110:                 status = r[:statuscode]
111:                 message = r[:statusmsg]
112:                 display = ddl[:display]
113:                 result = r[:data]
114: 
115:                 # appand the results only according to what the DDL says
116:                 case display
117:                 when :ok
118:                   if status == 0
119:                     result_text << text_for_result(sender, status, message, result, ddl)
120:                   end
121: 
122:                 when :failed
123:                   if status > 0
124:                     result_text << text_for_result(sender, status, message, result, ddl)
125:                   end
126: 
127:                 when :always
128:                   result_text << text_for_result(sender, status, message, result, ddl)
129: 
130:                 when :flatten
131:                   result_text << text_for_flattened_result(status, result)
132: 
133:                 end
134:               rescue Exception => e
135:                 # no DDL so just do the old style print unchanged for
136:                 # backward compat
137:                 result_text = old_rpcresults(result, flags)
138:               end
139:             end
140:           end
141:         end
142: 
143:         result_text
144:       end

Figures out the columns and liens of the current tty

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

[Source]

    # File lib/mcollective/rpc/helpers.rb, line 49
49:       def self.terminal_dimensions
50:         return [0, 0] unless STDOUT.tty?
51: 
52:         return [80, 40] if Util.windows?
53: 
54:         if ENV["COLUMNS"] && ENV["LINES"]
55:           return [ENV["COLUMNS"].to_i, ENV["LINES"].to_i]
56: 
57:         elsif ENV["TERM"] && command_in_path?("tput")
58:           return [`tput cols`.to_i, `tput lines`.to_i]
59: 
60:         elsif command_in_path?('stty')
61:           return `stty size`.scan(/\d+/).map {|s| s.to_i }
62:         else
63:           return [0, 0]
64:         end
65:       rescue
66:         [0, 0]
67:       end

Returns text representing a flattened result of only good data

[Source]

     # File lib/mcollective/rpc/helpers.rb, line 213
213:       def self.text_for_flattened_result(status, result)
214:         result_text = ""
215: 
216:         if status <= 1
217:           unless result.is_a?(String)
218:             result_text << result.pretty_inspect
219:           else
220:             result_text << result
221:           end
222:         end
223:       end

Return text representing a result

[Source]

     # File lib/mcollective/rpc/helpers.rb, line 147
147:       def self.text_for_result(sender, status, msg, result, ddl)
148:         statusses = ["",
149:                      Util.colorize(:red, "Request Aborted"),
150:                      Util.colorize(:yellow, "Unknown Action"),
151:                      Util.colorize(:yellow, "Missing Request Data"),
152:                      Util.colorize(:yellow, "Invalid Request Data"),
153:                      Util.colorize(:red, "Unknown Request Status")]
154: 
155:         result_text = "%-40s %s\n" % [sender, statusses[status]]
156:         result_text << "   %s\n" % [Util.colorize(:yellow, msg)] unless msg == "OK"
157: 
158:         # only print good data, ignore data that results from failure
159:         if [0, 1].include?(status)
160:           if result.is_a?(Hash)
161:             # figure out the lengths of the display as strings, we'll use
162:             # it later to correctly justify the output
163:             lengths = result.keys.map do |k|
164:               begin
165:                 ddl[:output][k][:display_as].size
166:               rescue
167:                 k.to_s.size
168:               end
169:             end
170: 
171:             result.keys.each do |k|
172:               # get all the output fields nicely lined up with a
173:               # 3 space front padding
174:               begin
175:                 display_as = ddl[:output][k][:display_as]
176:               rescue
177:                 display_as = k.to_s
178:               end
179: 
180:               display_length = display_as.size
181:               padding = lengths.max - display_length + 3
182:               result_text << " " * padding
183: 
184:               result_text << "#{display_as}:"
185: 
186:               if [String, Numeric].include?(result[k].class)
187:                 lines = result[k].to_s.split("\n")
188: 
189:                 if lines.empty?
190:                   result_text << "\n"
191:                 else
192:                   lines.each_with_index do |line, i|
193:                     i == 0 ? padtxt = " " : padtxt = " " * (padding + display_length + 2)
194: 
195:                     result_text << "#{padtxt}#{line}\n"
196:                   end
197:                 end
198:               else
199:                 padding = " " * (lengths.max + 5)
200:                 result_text << " " << result[k].pretty_inspect.split("\n").join("\n" << padding) << "\n"
201:               end
202:             end
203:           else
204:             result_text << "\n\t" + result.pretty_inspect.split("\n").join("\n\t")
205:           end
206:         end
207: 
208:         result_text << "\n"
209:         result_text
210:       end

[Validate]