Significantly reworked the type => provider interface with respect to

    listing existing provider instances.  The class method on both
    class heirarchies has been renamed to 'instances', to start.  Providers
    are now expected to return provider instances, instead of creating
    resources, and the resource's 'instances' method is expected to
    find the matching resource, if any, and set the resource's
    provider appropriately.  This *significantly* reduces the reliance on
    effectively global state (resource references in the resource classes).
    This global state will go away soon.

    Along with this change, the 'prefetch' class method on providers now
    accepts the list of resources for prefetching.  This again reduces
    reliance on global state, and makes the execution path much easier
    to follow.



git-svn-id: https://reductivelabs.com/svn/puppet/trunk@2551 980ebf18-57e1-0310-9a29-db15c13687c0

Author: luke

CHANGELOG

@@ -1,3 +1,18 @@
+    Significantly reworked the type => provider interface with respect to
+    listing existing provider instances.  The class method on both
+    class heirarchies has been renamed to 'instances', to start.  Providers
+    are now expected to return provider instances, instead of creating
+    resources, and the resource's 'instances' method is expected to
+    find the matching resource, if any, and set the resource's
+    provider appropriately.  This *significantly* reduces the reliance on
+    effectively global state (resource references in the resource classes).
+    This global state will go away soon.
+
+    Along with this change, the 'prefetch' class method on providers now
+    accepts the list of resources for prefetching.  This again reduces
+    reliance on global state, and makes the execution path much easier
+    to follow.
+
     Fixed #532 -- reparsing config files now longer throws an exception.
 
     Added some warnings and logs to the service type so

lib/puppet/metatype/instances.rb

@@ -248,6 +248,24 @@ def self.hash2trans(hash)
         return trans
     end
 
+    # Retrieve all known instances.  Either requires providers or must be overridden.
+    def self.instances
+        unless defined?(@providers) and ! @providers.empty?
+            raise Puppet::DevError, "%s has no providers and has not overridden 'instances'" % self.name
+        end
+
+        # Put the default provider first, then the rest of the suitable providers.
+        sources = []
+        [defaultprovider, suitableprovider].flatten.uniq.collect do |provider|
+            next if sources.include?(provider.source)
+
+            sources << provider.source
+            provider.instances.collect do |instance|
+                create(:name => instance.name, :provider => instance, :check => :all)
+            end
+        end.flatten.compact
+    end
+
     # Create the path for logging and such.
     def pathbuilder
         if defined? @parent and @parent

lib/puppet/metatype/providers.rb

@@ -86,26 +86,6 @@ def self.hash2obj(hash)
         return obj
     end
 
-    # Create a list method that just calls our providers.
-    def self.mkprovider_list
-        unless respond_to?(:list)
-            meta_def(:list) do
-                suitableprovider.find_all { |p| p.respond_to?(:list) }.collect { |prov|
-                    prov.list.each { |h| h[:provider] = prov.name }
-                }.flatten.collect do |hash|
-                    if hash.is_a?(Hash)
-                        hash2obj(hash)
-                    elsif hash.is_a?(self)
-                        hash
-                    else
-                        raise Puppet::DevError, "Provider %s returned object of type %s in list" %
-                            [prov.name, hash.class]
-                    end
-                end
-            end
-        end
-    end
-
     # Retrieve a provider by name.
     def self.provider(name)
         name = Puppet::Util.symbolize(name)
@@ -172,7 +152,6 @@ def self.provide(name, options = {}, &block)
     def self.providify
         return if @paramhash.has_key? :provider
 
-        mkprovider_list()
         newparam(:provider) do
             desc "The specific backend for #{self.name.to_s} to use. You will
                 seldom need to specify this -- Puppet will usually discover the
@@ -197,17 +176,21 @@ def self.doc
                 @resource.class.defaultprovider.name
             }
 
-            validate do |value|
-                value = value[0] if value.is_a? Array
-                if provider = @resource.class.provider(value)
+            validate do |provider_class|
+                provider_class = provider_class[0] if provider_class.is_a? Array
+                if provider_class.is_a?(Puppet::Provider)
+                    provider_class = provider_class.class.name
+                end
+
+                if provider = @resource.class.provider(provider_class)
                     unless provider.suitable?
                         raise ArgumentError,
                             "Provider '%s' is not functional on this platform" %
-                            [value]
+                            [provider_class]
                     end
                 else
                     raise ArgumentError, "Invalid %s provider '%s'" %
-                        [@resource.class.name, value]
+                        [@resource.class.name, provider_class]
                 end
             end
 
@@ -244,10 +227,13 @@ def self.suitableprovider
     end
 
     def provider=(name)
-        if klass = self.class.provider(name)
+        if name.is_a?(Puppet::Provider)
+            @provider = name
+            @provider.resource = self
+        elsif klass = self.class.provider(name)
             @provider = klass.new(self)
         else
-            raise UnknownProviderError, "Could not find %s provider of %s" %
+            raise ArgumentError, "Could not find %s provider of %s" %
                 [name, self.class.name]
         end
     end

lib/puppet/network/handler/resource.rb

@@ -145,7 +145,7 @@ def list(type, ignore = [], base = nil, format = "yaml", client = nil, clientip
             bucket = Puppet::TransBucket.new
             bucket.type = typeklass.name
 
-            typeklass.list.each do |obj|
+            typeklass.instances.each do |obj|
                 next if ignore.include? obj.name
 
                 #object = Puppet::TransObject.new(obj.name, typeklass.name)

lib/puppet/provider.rb

@@ -109,6 +109,12 @@ def self.initvars
         end
     end
 
+    # The method for returning a list of provider instances.  Note that it returns providers, preferably with values already
+    # filled in, not resources.
+    def self.instances
+        raise Puppet::DevError, "Provider %s has not defined the 'instances' class method" % self.name
+    end
+
     # Create the methods for a given command.
     def self.make_command_methods(name)
         # Now define a method for that command
@@ -323,16 +329,34 @@ def command(name)
         self.class.command(name)
     end
 
-    def initialize(resource)
-        @resource = resource
-
-        # LAK 2007-05-09: Keep the model stuff around for backward compatibility
-        @model = resource
-        @property_hash = {}
+    def initialize(resource = nil)
+        if resource.is_a?(Hash)
+            @property_hash = resource.dup
+        elsif resource
+            @resource = resource if resource
+            # LAK 2007-05-09: Keep the model stuff around for backward compatibility
+            @model = resource
+            @property_hash = {}
+        else
+            @property_hash = {}
+        end
     end
 
     def name
-        @resource.name
+        if n = @property_hash[:name]
+            return n
+        elsif self.resource
+            resource.name
+        else
+            raise Puppet::DevError, "No resource and no name in property hash"
+        end
+    end
+
+    # Set passed params as the current values.
+    def set(params)
+        params.each do |param, value|
+            @property_hash[symbolize(param)] = value
+        end
     end
 
     def to_s

lib/puppet/provider/nameservice/netinfo.rb

@@ -45,6 +45,12 @@ def self.finish
         end
     end
 
+    def self.instances
+        report(@resource_type.validproperties).collect do |hash|
+            self.new(hash)
+        end
+    end
+    
     # Convert a NetInfo line into a hash of data.
     def self.line2hash(line, params)
         values = line.split(/\t/)
@@ -61,12 +67,6 @@ def self.line2hash(line, params)
         hash
     end
 
-    def self.list
-        report(@resource_type.validproperties).collect do |hash|
-            @resource_type.hash2obj(hash)
-        end
-    end
-    
     # What field the value is stored under.
     def self.netinfokey(name)
         name = symbolize(name)

lib/puppet/provider/package/apple.rb

@@ -11,7 +11,17 @@
 
     defaultfor :operatingsystem => :darwin
 
-    def self.listbyname
+    def self.instances
+        instance_by_name.collect do |name|
+            self.new(
+                :name => name,
+                :provider => :apple,
+                :ensure => :installed
+            )
+        end
+    end
+
+    def self.instance_by_name
         Dir.entries("/Library/Receipts").find_all { |f|
             f =~ /\.pkg$/
         }.collect { |f|
@@ -22,16 +32,6 @@ def self.listbyname
         }
     end
 
-    def self.list
-        listbyname.collect do |name|
-            Puppet.type(:package).installedpkg(
-                :name => name,
-                :provider => :apple,
-                :ensure => :installed
-            )
-        end
-    end
-
     def query
         if FileTest.exists?("/Library/Receipts/#{@resource[:name]}.pkg")
             return {:name => @resource[:name], :ensure => :present}

lib/puppet/provider/package/blastwave.rb

@@ -23,10 +23,10 @@ def self.extended(mod)
         end
     end
 
-    def self.list(hash = {})
+    def self.instances(hash = {})
         blastlist(hash).collect do |bhash|
             bhash.delete(:avail)
-            Puppet::Type.type(:package).installedpkg(bhash)
+            new(bhash)
         end
     end
 

lib/puppet/provider/package/darwinport.rb

@@ -31,12 +31,11 @@ def self.eachpkgashash
         }
     end
 
-    def self.list
+    def self.instances
         packages = []
 
         eachpkgashash do |hash|
-            pkg = Puppet.type(:package).installedpkg(hash)
-            packages << pkg
+            packages << new(hash)
         end
 
         return packages

lib/puppet/provider/package/dpkg.rb

@@ -6,7 +6,7 @@
     commands :dpkg => "/usr/bin/dpkg"
     commands :dpkgquery => "/usr/bin/dpkg-query"
 
-    def self.list
+    def self.instances
         packages = []
 
         # list out all of the packages
@@ -29,7 +29,7 @@ def self.list
 
                     hash[:provider] = self.name
 
-                    packages.push Puppet.type(:package).installedpkg(hash)
+                    packages << new(hash)
                 else
                     Puppet.warning "Failed to match dpkg-query line %s" %
                         line.inspect

lib/puppet/provider/package/gem.rb

@@ -56,9 +56,9 @@ def self.gemsplit(desc)
         end
     end
 
-    def self.list(justme = false)
+    def self.instances(justme = false)
         gemlist(:local => true).collect do |hash|
-            Puppet::Type.type(:package).installedpkg(hash)
+            new(hash)
         end
     end
 

lib/puppet/provider/package/openbsd.rb

@@ -7,7 +7,7 @@
     defaultfor :operatingsystem => :openbsd
     confine :operatingsystem => :openbsd
 
-    def self.list
+    def self.instances
         packages = []
 
         begin
@@ -29,21 +29,14 @@ def self.list
 
                         hash[:provider] = self.name
 
-                        pkg = Puppet.type(:package).installedpkg(hash)
-                        packages << pkg
+                        packages << new(hash)
                     else
                         # Print a warning on lines we can't match, but move
                         # on, since it should be non-fatal
                         warning("Failed to match line %s" % line)
                     end
                 }
             end
-            # Mark as absent any packages we didn't find
-            Puppet.type(:package).each do |pkg|
-                unless packages.include? pkg
-                    pkg.is = [:ensure, :absent] 
-                end
-            end
 
             return packages
         rescue Puppet::ExecutionFailure

lib/puppet/provider/package/pkgdmg.rb

@@ -23,7 +23,7 @@
     commands :curl => "/usr/bin/curl"
 
     # JJM We store a cookie for each installed .pkg.dmg in /var/db
-    def self.listbyname
+    def self.instance_by_name
         Dir.entries("/var/db").find_all { |f|
             f =~ /^\.puppet_pkgdmg_installed_/
         }.collect do |f|
@@ -33,9 +33,9 @@ def self.listbyname
         end
     end
 
-    def self.list
-        listbyname.collect do |name|
-            Puppet.type(:package).installedpkg(
+    def self.instances
+        instance_by_name.collect do |name|
+            new(
                 :name => name,
                 :provider => :pkgdmg,
                 :ensure => :installed

lib/puppet/provider/package/portage.rb

@@ -7,7 +7,7 @@
 
     defaultfor :operatingsystem => :gentoo
 
-    def self.list
+    def self.instances
         result_format = /(\S+) (\S+) \[(.*)\] \[[^0-9]*([^\s:]*)(:\S*)?\] ([\S]*) (.*)/
         result_fields = [:category, :name, :ensure, :version_available, :slot, :vendor, :description]
 
@@ -28,7 +28,7 @@ def self.list
                     package[:provider] = :portage
                     package[:ensure] = package[:ensure].split.last
 
-                    packages.push(Puppet.type(:package).installedpkg(package))
+                    packages << new(package)
                 end
             end
 

lib/puppet/provider/package/rpm.rb

@@ -10,7 +10,7 @@
 
     commands :rpm => "rpm"
 
-    def self.list
+    def self.instances
         packages = []
 
         # list out all of the packages
@@ -30,7 +30,7 @@ def self.list
                             hash[field] = value
                         }
                         hash[:provider] = self.name
-                        packages.push Puppet.type(:package).installedpkg(hash)
+                        packages << new(hash)
                     else
                         raise "failed to match rpm line %s" % line
                     end