(#5605) Prefetch doesnt work with composite keys

The uniqueness_key method of a type or resource object should return a
key that can be used to identify this resource. In fact puppet seldomly
uses this method and instead uses resource[:name] as an identifier.

While this is totally fine for resourcetypes with a single
key_attribute (and resource[:name] returning the namevar), it breaks
things as soon as one creates a type with a composite key (prefetching
for example is broken). To ease the process of replacing calls to
resource[:name] to resource.uniqueness_key, the method uniqueness_key now
just returns name_var if there is only one key_attribute (immitating
self[:name]) and only returns an array of all the values of all the
key_attributes if we have more than one key_attribute.

The resourcehash which is passed to providers in their prefetch method
is now build with uniqueness_key as the hashkey. Because of the new
behaviour of uniqueness_key we hopefully wont break existing providers
while allowing new providers for types with composite keys to implement
correct prefetch methods.

1 files changed, 9 insertions, 2 deletions

diff --git a/spec/unit/resource_spec.rb b/spec/unit/resource_spec.rb
index e65e8a13a..092ae8ce0 100755
--- a/spec/unit/resource_spec.rb
+++ b/spec/unit/resource_spec.rb
@@ -268,7 +268,7 @@ describe Puppet::Resource do
   describe "when referring to a resource with name canonicalization" do
     it "should canonicalize its own name" do
       res = Puppet::Resource.new("file", "/path/")
-      res.uniqueness_key.should == ["/path"]
+      res.uniqueness_key.should == "/path"
       res.ref.should == "File[/path/]"
     end
   end
@@ -770,7 +770,14 @@ describe Puppet::Resource do
   end
 
   describe "when generating the uniqueness key" do
-    it "should include all of the key_attributes in alphabetical order by attribute name" do
+
+    it "should use namevar if there is only one key_attribute" do
+      Puppet::Type.type(:file).stubs(:key_attributes).returns [:path]
+      res = Puppet::Resource.new("file", "/my/file", :parameters => {:owner => 'root', :content => 'hello'})
+      res.uniqueness_key.should == '/my/file'
+    end
+
+    it "should include all of the key_attributes" do
       Puppet::Type.type(:file).stubs(:key_attributes).returns [:myvar, :owner, :path]
       Puppet::Type.type(:file).stubs(:title_patterns).returns(
         [ [ /(.*)/, [ [:path, lambda{|x| x} ] ] ] ]