require 'erb' require 'json/pure' # pure ruby implementation is required for our sorted trick to work. if $ruby_version < [1,9] $KCODE = 'UTF8' end require 'ya2yaml' # pure ruby yaml require 'leap_cli/config/macros' 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 include Config::Macros attr_reader :node attr_reader :manager 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 end # # We use pure ruby yaml exporter ya2yaml instead of SYCK or PSYCH because it # allows us greater compatibility regardless of installed ruby version and # greater control over how the yaml is exported (sorted keys, in particular). # def dump evaluate ya2yaml(:syck_compatible => true) end def dump_json evaluate JSON.sorted_generate(self) end def evaluate evaluate_everything late_evaluate_everything end ## ## FETCHING VALUES ## 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 # override behavior of #default() from Hash def default get!('default') end # # Like a normal Hash#[], except: # # (1) lazily eval dynamic values when we encounter them. (i.e. strings that start with "= ") # # (2) support for nested references in a single string (e.g. ['a.b'] is the same as ['a']['b']) # the dot path is always absolute, starting at the top-most object. # def get!(key) key = key.to_s if key =~ /\./ # for keys with with '.' in them, we start from the root object (@node). keys = key.split('.') value = @node.get!(keys.first) if value.is_a? Config::Object value.get!(keys[1..-1].join('.')) else value end elsif self.has_key?(key) fetch_value(key) else raise NoMethodError.new(key, "No method '#{key}' for #{self.class}") end end ## ## COPYING ## # # A deep (recursive) merge with another Config::Object. # # If prefer_self is set to true, the value from self will be picked when there is a conflict # that cannot be merged. # # Merging rules: # # - If a value is a hash, we recursively merge it. # - If the value is simple, like a string, the new one overwrites the value. # - If the value is an array: # - If both old and new values are arrays, the new one replaces the old. # - If one of the values is simple but the other is an array, the simple is added to the array. # def deep_merge!(object, prefer_self=false) object.each do |key,new_value| old_value = self.fetch key, nil # clean up boolean new_value = true if new_value == "true" new_value = false if new_value == "false" old_value = true if old_value == "true" old_value = false if old_value == "false" # merge hashes if old_value.is_a?(Hash) || new_value.is_a?(Hash) value = Config::Object.new(@manager, @node) old_value.is_a?(Hash) ? value.deep_merge!(old_value) : (value[key] = old_value if !old_value.nil?) new_value.is_a?(Hash) ? value.deep_merge!(new_value, prefer_self) : (value[key] = new_value if !new_value.nil?) # merge nil elsif new_value.nil? value = old_value elsif old_value.nil? value = new_value # merge arrays when one value is not an array elsif old_value.is_a?(Array) && !new_value.is_a?(Array) value = (old_value.dup << new_value).compact.uniq elsif new_value.is_a?(Array) && !old_value.is_a?(Array) value = (new_value.dup << old_value).compact.uniq # catch errors elsif type_mismatch?(old_value, new_value) raise 'Type mismatch. Cannot merge %s (%s) with %s (%s). Key is "%s", name is "%s".' % [ old_value.inspect, old_value.class, new_value.inspect, new_value.class, key, self.class ] # merge strings, numbers, and sometimes arrays else if prefer_self value = old_value else value = new_value end end # save value self[key] = value end self end # # like a reverse deep merge # (self takes precedence) # def inherit_from!(object) self.deep_merge!(object, true) end protected # # walks the object tree, eval'ing all the attributes that are dynamic ruby (e.g. value starts with '= ') # def evaluate_everything keys.each do |key| obj = fetch_value(key) if obj == "REQUIRED" Util::log 0, :warning, "required key \"#{key}\" is not set in node \"#{node.name}\"." elsif obj.is_a? Config::Object obj.evaluate_everything end end end # # some keys need to be evaluated 'late', after all the other keys have been evaluated. # def late_evaluate_everything if @late_eval_list @late_eval_list.each do |key, value| self[key] = evaluate_now(key, value) if self[key] == "REQUIRED" Util::log 0, :warning, "required key \"#{key}\" is not set in node \"#{node.name}\"." end end end values.each do |obj| if obj.is_a? Config::Object obj.late_evaluate_everything end end end private # # fetches the value for the key, evaluating the value as ruby if it begins with '=' # def fetch_value(key) value = fetch(key, nil) if value.is_a?(String) && value =~ /^=/ if value =~ /^=> (.*)$/ value = evaluate_later(key, $1) elsif value =~ /^= (.*)$/ value = evaluate_now(key, $1) end self[key] = value end return value end def evaluate_later(key, value) @late_eval_list ||= [] @late_eval_list << [key, value] '' end def evaluate_now(key, value) result = nil if LeapCli.log_level >= 2 result = @node.instance_eval(value) else begin result = @node.instance_eval(value) rescue SystemStackError => exc Util::log 0, :error, "while evaluating node '#{@node.name}'" Util::log 0, "offending key: #{key}", :indent => 1 Util::log 0, "offending string: #{value}", :indent => 1 Util::log 0, "STACK OVERFLOW, BAILING OUT. There must be an eval loop of death (variables with circular dependencies).", :indent => 1 raise SystemExit.new(1) rescue FileMissing => exc Util::bail! do if exc.options[:missing] Util::log :missing, exc.options[:missing].gsub('$node', @node.name) else Util::log :error, "while evaluating node '#{@node.name}'" Util::log "offending key: #{key}", :indent => 1 Util::log "offending string: #{value}", :indent => 1 Util::log "error message: no file '#{exc}'", :indent => 1 end end rescue SyntaxError, StandardError => exc Util::bail! do Util::log :error, "while evaluating node '#{@node.name}'" Util::log "offending key: #{key}", :indent => 1 Util::log "offending string: #{value}", :indent => 1 Util::log "error message: #{exc.inspect}", :indent => 1 end end end return result end # # when merging, we raise an error if this method returns true for the two values. # def type_mismatch?(old_value, new_value) if old_value.is_a?(Boolean) && new_value.is_a?(Boolean) # note: FalseClass and TrueClass are different classes # so we can't do old_value.class == new_value.class return false elsif old_value.is_a?(String) && old_value =~ /^=/ # pass through macros, since we don't know what the type will eventually be. return false elsif new_value.is_a?(String) && new_value =~ /^=/ return false elsif old_value.class == new_value.class return false else return true end end end # class end # module end # module