Signed-off-by: Eric Sorenson <[email protected]> --- ext/regexp_nodes.rb | 199 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 199 insertions(+), 0 deletions(-) create mode 100644 ext/regexp_nodes.rb
diff --git a/ext/regexp_nodes.rb b/ext/regexp_nodes.rb new file mode 100644 index 0000000..6a8e6da --- /dev/null +++ b/ext/regexp_nodes.rb @@ -0,0 +1,199 @@ +#!/usr/bin/env ruby + +# = Synopsis +# This is an external node classifier script, after +# http://reductivelabs.com/trac/puppet/wiki/ExternalNodes +# +# = Usage +# regexp_nodes.rb <host> +# +# = Description +# This classifier implements filesystem autoloading: +# We look through classes/ and parameters/ subdirectories, looping +# through each file we find there - the contents are a regexp-per-line +# which, if they match the hostname passed us as ARGV[0], will cause +# a class or parameter named the same thing as the file to be set. +# +# = Author +# Eric Sorenson <[email protected]> + + +# we need yaml or there's not much point in going on +require 'yaml' + +# Sets are like arrays but automatically de-duplicate elements +require 'set' + +# set up some nice logging +require 'logger' +# XXX flip this for production vs local sandbox +# $LOG = Logger.new("/var/puppet/log/extnodes.log") +# $LOG.level = Logger::FATAL +$LOG = Logger.new($stderr) +$LOG.level = Logger::DEBUG + +# paths for files we use will be relative to this directory +# XXX flip this for production vs local sandbox +# WORKINGDIR = "/var/puppet/bin" +WORKINGDIR = Dir.pwd + +# This class holds all the methods for creating and accessing the properties +# of an external node. There are really only two public methods: initialize() +# and a special version of to_yaml() + +class ExternalNode + # Make these instance variables get/set-able with eponymous methods + attr_accessor :classes, :parameters, :hostname + + # initialize() takes three arguments: + # hostname:: usually passed in via ARGV[0] but it could be anything + # classdir:: directory under WORKINGDIR to look for files named after + # classes + # parameterdir:: directory under WORKINGDIR to look for directories to set + # parameters + def initialize(hostname, classdir = 'classes/', parameterdir = 'parameters/') + # instance variables that contain the lists of classes and parameters + @hostname + @classes = Set.new ["baseclass"] + @parameters = Hash.new("unknown") # sets a default value of "unknown" + + self.parse_argv(hostname) + self.match_classes(WORKINGDIR + "/" + classdir) + self.match_parameters(WORKINGDIR + "/" + parameterdir) + end + + # private method called by initialize() which sanity-checks our hostname. + # good candidate for overriding in a subclass if you need different checks + def parse_argv(hostname) + if hostname =~ /^([-\w]+?)\.([-\w\.]+)/ # non-greedy up to the first . is hostname + @hostname = $1 + elsif hostname =~ /^([-\w]+)$/ # sometimes puppet's @name is just a name + @hostname = hostname + else + $LOG.fatal("didn't receive parsable hostname, got: [#{hostname}]") + exit(1) + end + end + + # to_yaml massages a copy of the object and outputs clean yaml so we don't + # feed weird things back to puppet []< + def to_yaml + classes = self.classes.to_a + if self.parameters.empty? # otherwise to_yaml prints "parameters: {}" + parameters = nil + else + parameters = self.parameters + end + ({ 'classes' => classes, 'parameters' => parameters}).to_yaml + end + + # Private method that expects an absolute path to a file and a string to + # match - it returns true if the string was matched by any of the lines in + # the file + def matched_in_patternfile?(filepath, matchthis) + + patternlist = [] + + begin + open(filepath).each { |l| + pattern = %r{#{l.chomp!}} + patternlist << pattern + $LOG.debug("appending [#{pattern}] to patternlist for [#{filepath}]") + } + rescue Exception + $LOG.fatal("Problem reading #{filepath}: #{$!}") + exit(1) + end + + $LOG.debug("list of patterns for #{filepath}: #{patternlist}") + + if matchthis =~ Regexp.union(patternlist) + $LOG.debug("matched #{$~.to_s} in #{matchthis}, returning true") + return true + + else # hostname didn't match anything in patternlist + $LOG.debug("#{matchthis} unmatched, returning false") + return nil + end + + end # def + + # private method - takes a path to look for files, iterates through all + # readable, regular files it finds, and matches this instance's @hostname + # against each line; if any match, the class will be set for this node. + def match_classes(fullpath) + Dir.foreach(fullpath) do |patternfile| + filepath = "#{fullpath}/#{patternfile}" + next unless File.file?(filepath) and + File.readable?(filepath) + $LOG.debug("Attempting to match [...@hostname}] in [#{filepath}]") + if matched_in_patternfile?(filepath,@hostname) + @classes << patternfile.to_s + $LOG.debug("Appended #{patternfile.to_s} to classes instance variable") + end # if + end # Dir.foreach + end # def + + # Parameters are handled slightly differently; we make another level of + # directories to get the parameter name, then use the names of the files + # contained in there for the values of those parameters. + # + # ex: cat /var/puppet/bin/parameters/environment/production + # ^prodweb + # would set parameters["environment"] = "production" for prodweb001 + def match_parameters(fullpath) + Dir.foreach(fullpath) do |parametername| + + filepath = "#{fullpath}/#{parametername}" + next if File.basename(filepath) =~ /^\./ # skip over dotfiles + + next unless File.directory?(filepath) and + File.readable?(filepath) # skip over non-directories + + $LOG.debug "Considering contents of #{filepath}" + + Dir.foreach("#{filepath}") do |patternfile| + secondlevel = "#{filepath}/#{patternfile}" + $LOG.debug "Found parameters patternfile at #{secondlevel}" + next unless File.file?(secondlevel) and + File.readable?(secondlevel) + $LOG.debug("Attempting to match [...@hostname}] in [#{secondlevel}]") + if matched_in_patternfile?(secondlevel, @hostname) + @parameters[ parametername.to_s ] = patternfile.to_s + $LOG.debug("Set @parameters[#{parametername.to_s}] = #{patternfile.to_s}") + end # if + end # Dir.foreach #{filepath} + end # Dir.foreach #{fullpath} + end # def + +end # Class + +# Logic for local hacks that don't fit neatly into the autoloading model can +# happen as we initialize a subclass +class MyExternalNode < ExternalNode + + def initialize(hostname, classdir = 'classes/', parameterdir = 'parameters/') + + super + + # Set "hostclass" parameter based on hostname, + # stripped of leading environment prefix and numeric suffix + if @hostname =~ /^(\w*?)-?(\D+)(\d{2,3})$/ + match = Regexp.last_match + + hostclass = match[2] + $LOG.debug("matched hostclass #{hostclass}") + @parameters[ "hostclass" ] = hostclass + else + $LOG.debug("hostclass couldn't figure out class from #...@hostname}") + end # if + end # def + +end # Class + + +# Here we begin actual execution by calling methods defined above + +mynode = MyExternalNode.new(ARGV[0]) + +puts mynode.to_yaml -- 1.6.4.3 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Puppet Developers" group. 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