diff --git a/lib/puppet/indirector/indirection.rb b/lib/puppet/indirector/indirection.rb index a010c4e40..4341f7cb2 100644 --- a/lib/puppet/indirector/indirection.rb +++ b/lib/puppet/indirector/indirection.rb @@ -1,308 +1,307 @@ require 'puppet/util/docs' require 'puppet/indirector/envelope' require 'puppet/indirector/request' require 'puppet/util/cacher' # The class that connects functional classes with their different collection # back-ends. Each indirection has a set of associated terminus classes, # each of which is a subclass of Puppet::Indirector::Terminus. class Puppet::Indirector::Indirection include Puppet::Util::Cacher include Puppet::Util::Docs @@indirections = [] # Find an indirection by name. This is provided so that Terminus classes # can specifically hook up with the indirections they are associated with. def self.instance(name) @@indirections.find { |i| i.name == name } end # Return a list of all known indirections. Used to generate the # reference. def self.instances @@indirections.collect { |i| i.name } end # Find an indirected model by name. This is provided so that Terminus classes # can specifically hook up with the indirections they are associated with. def self.model(name) return nil unless match = @@indirections.find { |i| i.name == name } match.model end attr_accessor :name, :model # Create and return our cache terminus. def cache raise(Puppet::DevError, "Tried to cache when no cache class was set") unless cache_class terminus(cache_class) end # Should we use a cache? def cache? cache_class ? true : false end attr_reader :cache_class # Define a terminus class to be used for caching. def cache_class=(class_name) validate_terminus_class(class_name) if class_name @cache_class = class_name end # This is only used for testing. def delete @@indirections.delete(self) if @@indirections.include?(self) end # Set the time-to-live for instances created through this indirection. def ttl=(value) raise ArgumentError, "Indirection TTL must be an integer" unless value.is_a?(Fixnum) @ttl = value end # Default to the runinterval for the ttl. def ttl @ttl ||= Puppet[:runinterval].to_i end # Calculate the expiration date for a returned instance. def expiration Time.now + ttl end # Generate the full doc string. def doc text = "" text += scrub(@doc) + "\n\n" if @doc if s = terminus_setting text += "* **Terminus Setting**: #{terminus_setting}" end text end def initialize(model, name, options = {}) @model = model @name = name @cache_class = nil @terminus_class = nil raise(ArgumentError, "Indirection #{@name} is already defined") if @@indirections.find { |i| i.name == @name } @@indirections << self if mod = options[:extend] extend(mod) options.delete(:extend) end # This is currently only used for cache_class and terminus_class. options.each do |name, value| begin send(name.to_s + "=", value) rescue NoMethodError raise ArgumentError, "#{name} is not a valid Indirection parameter" end end end # Set up our request object. def request(*args) Puppet::Indirector::Request.new(self.name, *args) end # Return the singleton terminus for this indirection. def terminus(terminus_name = nil) # Get the name of the terminus. raise Puppet::DevError, "No terminus specified for #{self.name}; cannot redirect" unless terminus_name ||= terminus_class termini[terminus_name] ||= make_terminus(terminus_name) end # This can be used to select the terminus class. attr_accessor :terminus_setting # Determine the terminus class. def terminus_class unless @terminus_class if setting = self.terminus_setting self.terminus_class = Puppet.settings[setting].to_sym else raise Puppet::DevError, "No terminus class nor terminus setting was provided for indirection #{self.name}" end end @terminus_class end def reset_terminus_class @terminus_class = nil end # Specify the terminus class to use. def terminus_class=(klass) validate_terminus_class(klass) @terminus_class = klass end # This is used by terminus_class= and cache=. def validate_terminus_class(terminus_class) raise ArgumentError, "Invalid terminus name #{terminus_class.inspect}" unless terminus_class and terminus_class.to_s != "" unless Puppet::Indirector::Terminus.terminus_class(self.name, terminus_class) raise ArgumentError, "Could not find terminus #{terminus_class} for indirection #{self.name}" end end # Expire a cached object, if one is cached. Note that we don't actually # remove it, we expire it and write it back out to disk. This way people # can still use the expired object if they want. def expire(key, *args) request = request(:expire, key, *args) return nil unless cache? return nil unless instance = cache.find(request(:find, key, *args)) Puppet.info "Expiring the #{self.name} cache of #{instance.name}" # Set an expiration date in the past instance.expiration = Time.now - 60 cache.save(request(:save, instance, *args)) end # Search for an instance in the appropriate terminus, caching the # results if caching is configured.. def find(key, *args) request = request(:find, key, *args) terminus = prepare(request) - begin - if result = find_in_cache(request) - return result - end - rescue => detail - puts detail.backtrace if Puppet[:trace] - Puppet.err "Cached #{self.name} for #{request.key} failed: #{detail}" + if result = find_in_cache(request) + return result end # Otherwise, return the result from the terminus, caching if appropriate. if ! request.ignore_terminus? and result = terminus.find(request) result.expiration ||= self.expiration if result.respond_to?(:expiration) if cache? and request.use_cache? Puppet.info "Caching #{self.name} for #{request.key}" cache.save request(:save, result, *args) end return terminus.respond_to?(:filter) ? terminus.filter(result) : result end nil end def find_in_cache(request) # See if our instance is in the cache and up to date. return nil unless cache? and ! request.ignore_cache? and cached = cache.find(request) if cached.expired? Puppet.info "Not using expired #{self.name} for #{request.key} from cache; expired at #{cached.expiration}" return nil end Puppet.debug "Using cached #{self.name} for #{request.key}" cached + rescue => detail + puts detail.backtrace if Puppet[:trace] + Puppet.err "Cached #{self.name} for #{request.key} failed: #{detail}" + nil end # Remove something via the terminus. def destroy(key, *args) request = request(:destroy, key, *args) terminus = prepare(request) result = terminus.destroy(request) if cache? and cached = cache.find(request(:find, key, *args)) # Reuse the existing request, since it's equivalent. cache.destroy(request) end result end # Search for more than one instance. Should always return an array. def search(key, *args) request = request(:search, key, *args) terminus = prepare(request) if result = terminus.search(request) raise Puppet::DevError, "Search results from terminus #{terminus.name} are not an array" unless result.is_a?(Array) result.each do |instance| instance.expiration ||= self.expiration end return result end end # Save the instance in the appropriate terminus. This method is # normally an instance method on the indirected class. def save(key, instance = nil) request = request(:save, key, instance) terminus = prepare(request) result = terminus.save(request) # If caching is enabled, save our document there cache.save(request) if cache? result end private # Check authorization if there's a hook available; fail if there is one # and it returns false. def check_authorization(request, terminus) # At this point, we're assuming authorization makes no sense without # client information. return unless request.node # This is only to authorize via a terminus-specific authorization hook. return unless terminus.respond_to?(:authorized?) unless terminus.authorized?(request) msg = "Not authorized to call #{request.method} on #{request}" msg += " with #{request.options.inspect}" unless request.options.empty? raise ArgumentError, msg end end # Setup a request, pick the appropriate terminus, check the request's authorization, and return it. def prepare(request) # Pick our terminus. if respond_to?(:select_terminus) unless terminus_name = select_terminus(request) raise ArgumentError, "Could not determine appropriate terminus for #{request}" end else terminus_name = terminus_class end dest_terminus = terminus(terminus_name) check_authorization(request, dest_terminus) dest_terminus end # Create a new terminus instance. def make_terminus(terminus_class) # Load our terminus class. unless klass = Puppet::Indirector::Terminus.terminus_class(self.name, terminus_class) raise ArgumentError, "Could not find terminus #{terminus_class} for indirection #{self.name}" end klass.new end # Cache our terminus instances indefinitely, but make it easy to clean them up. cached_attr(:termini) { Hash.new } end