require 'erb' require 'json/pure' # pure ruby implementation is required for our sorted trick to work. module LeapCli module Config # # This class represents the configuration for a single node, service, or tag. # Also, all the nested hashes are also of this type. # # It is called 'object' because it corresponds to an Object in JSON. # class Object < Hash attr_reader :node attr_reader :manager attr_reader :node_list alias :global :manager def initialize(manager=nil, node=nil) # keep a global pointer around to the config manager. used a lot in the eval strings and templates # (which are evaluated in the context of Config::Object) @manager = manager # an object that is a node as @node equal to self, otherwise all the child objects point back to the top level node. @node = node || self # this is only used by Config::Objects that correspond to services or tags. @node_list = Config::ObjectList.new end ## ## FETCHING VALUES ## # # like a normal hash [], except: # * lazily eval dynamic values when we encounter them. # * support for nested hashes (e.g. ['a.b'] is the same as ['a']['b']) # def [](key) get(key) end # # make hash addressable like an object (e.g. obj['name'] available as obj.name) # def method_missing(method, *args, &block) get!(method) end def get(key) begin get!(key) rescue NoMethodError nil end end def get!(key) key = key.to_s if key =~ /\./ keys = key.split('.') value = get!(keys.first) if value.is_a? Config::Object value.get!(keys[1..-1]) else value end elsif self.has_key?(key) evaluate_value(key) elsif @node != self @node.get!(key) else raise NoMethodError.new(key, "No method '#{key}' for #{self.class}") end end ## ## COPYING ## # # Make a copy of ourselves, except only including the specified keys. # # Also, the result is flattened to a single hash, so a key of 'a.b' becomes 'a_b' # def pick(*keys) keys.map(&:to_s).inject(Config::Object.new(@manager,@node)) do |hsh, key| value = self.get(key) if value hsh[key.gsub('.','_')] = value end hsh end end # # a deep (recursive) merge with another Config::Object. # def deep_merge!(object) object.each do |key,new_value| old_value = self[key] if old_value.is_a?(Hash) || new_value.is_a?(Hash) # merge hashes value = Config::Object.new(@manager, @node) old_value.is_a?(Hash) ? value.deep_merge!(old_value) : (value[key] = old_value if old_value.any?) new_value.is_a?(Hash) ? value.deep_merge!(new_value) : (value[key] = new_value if new_value.any?) elsif old_value.is_a?(Array) || new_value.is_a?(Array) # merge arrays value = [] old_value.is_a?(Array) ? value += old_value : value << old_value new_value.is_a?(Array) ? value += new_value : value << new_value value.compact! elsif new_value.nil? value = old_value elsif old_value.nil? value = new_value elsif old_value.is_a?(Boolean) && new_value.is_a?(Boolean) value = new_value elsif old_value.class != new_value.class raise 'Type mismatch. Cannot merge %s with %s. Key value is %s, name is %s.' % [old_value.class, new_value.class, key, name] else value = new_value end self[key] = value end self end private # # fetches the value for the key, evaluating the value as ruby if it begins with '=' # def evaluate_value(key) value = fetch(key, nil) if value.is_a? Array value elsif value.nil? nil else if value =~ /^= (.*)$/ begin value = eval($1, self.send(:binding)) self[key] = value rescue SystemStackError => exc puts "STACK OVERFLOW, BAILING OUT" puts "There must be an eval loop of death (variables with circular dependencies). This is the offending string:" puts puts " #{$1}" puts raise SystemExit.new() rescue StandardError => exc puts "Eval error in '#{@node.name}'" puts " string: #{$1}" puts " error: #{exc.name}" end end value end end ## ## MACROS ## these are methods used when eval'ing a value in the .json configuration ## # # the list of all the nodes # def nodes global.nodes end # # inserts the contents of a file # def file(filename) filepath = Path.find_file(@node.name, filename) if filepath if filepath =~ /\.erb$/ ERB.new(File.read(filepath), nil, '%<>').result(binding) else File.read(filepath) end else log0('no such file, "%s"' % filename) "" end end # # Output json from ruby objects in such a manner that all the hashes and arrays are output in alphanumeric sorted order. # This is required so that our generated configs don't throw puppet or git for a tizzy fit. # # Beware: some hacky stuff ahead. # # This relies on the pure ruby implementation of JSON.generate (i.e. require 'json/pure') # see https://github.com/flori/json/blob/master/lib/json/pure/generator.rb # # The Oj way that we are not using: Oj.dump(obj, :mode => :compat, :indent => 2) # def generate_json(obj) # modify hash and array Hash.class_eval do alias_method :each_without_sort, :each def each(&block) keys.sort {|a,b| a.to_s <=> b.to_s }.each do |key| yield key, self[key] end end end Array.class_eval do alias_method :each_without_sort, :each def each(&block) sort {|a,b| a.to_s <=> b.to_s }.each_without_sort &block end end # generate json return_value = JSON.pretty_generate(obj) # restore hash and array Hash.class_eval {alias_method :each, :each_without_sort} Array.class_eval {alias_method :each, :each_without_sort} return return_value end end # class end # module end # module