(#5171) Made filebucket able to perform diffs

It is now possible to ask the filebucket to diff two files using a URL
of the form:

https://puppet/production/file_bucket_file/md5/{first file hash}?diff_with={second file hash}

The returned diff is a string, the output of the "diff" command.

Paired-with: Paul Berry <paul@puppetlabs.com>

5 files changed, 67 insertions, 3 deletions

diff --git a/lib/puppet/indirector/file_bucket_file/file.rb b/lib/puppet/indirector/file_bucket_file/file.rb
index 318858aaf..9d9cee793 100644
--- a/lib/puppet/indirector/file_bucket_file/file.rb
+++ b/lib/puppet/indirector/file_bucket_file/file.rb
@@ -15,7 +15,16 @@ module Puppet::FileBucketFile
 
     def find( request )
       checksum, path = request_to_checksum_and_path( request )
-      find_by_checksum( checksum, request.options )
+      file = find_by_checksum( checksum, request.options )
+
+      if file && request.options[:diff_with]
+        hash_protocol = sumtype(checksum)
+        file2 = find_by_checksum( "{#{hash_protocol}}#{request.options[:diff_with]}", request.options )
+        raise "could not find diff_with #{request.options[:diff_with]}" unless file2
+        return `diff #{path_for(file).inspect}/contents #{path_for(file2).inspect}/contents`
+      end
+
+      file
     end
 
     def save( request )
diff --git a/lib/puppet/indirector/indirection.rb b/lib/puppet/indirector/indirection.rb
index 309eed7b6..a010c4e40 100644
--- a/lib/puppet/indirector/indirection.rb
+++ b/lib/puppet/indirector/indirection.rb
@@ -191,7 +191,7 @@ class Puppet::Indirector::Indirection
 
     # Otherwise, return the result from the terminus, caching if appropriate.
     if ! request.ignore_terminus? and result = terminus.find(request)
-      result.expiration ||= self.expiration
+      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)
diff --git a/lib/puppet/network/http/handler.rb b/lib/puppet/network/http/handler.rb
index 61ae2d2fc..f22498b70 100644
--- a/lib/puppet/network/http/handler.rb
+++ b/lib/puppet/network/http/handler.rb
@@ -109,7 +109,11 @@ module Puppet::Network::HTTP::Handler
     format = format_to_use(request)
     set_content_type(response, format)
 
-    set_response(response, result.render(format))
+    if result.respond_to?(:render)
+      set_response(response, result.render(format))
+    else
+      set_response(response, result)
+    end
   end
 
   # Execute our search.
diff --git a/spec/unit/indirector/file_bucket_file/file_spec.rb b/spec/unit/indirector/file_bucket_file/file_spec.rb
index aa3ade6b6..7bf02b5b3 100755
--- a/spec/unit/indirector/file_bucket_file/file_spec.rb
+++ b/spec/unit/indirector/file_bucket_file/file_spec.rb
@@ -13,6 +13,51 @@ describe Puppet::FileBucketFile::File do
     Puppet::FileBucketFile::File.doc.should be_instance_of(String)
   end
 
+  describe "non-stubbing tests" do
+    include PuppetSpec::Files
+
+    before do
+      Puppet[:bucketdir] = tmpdir('bucketdir')
+    end
+
+    describe "when diffing files" do
+      def save_bucket_file(contents)
+        bucket_file = Puppet::FileBucket::File.new(contents)
+        bucket_file.save
+        bucket_file.checksum_data
+      end
+
+      it "should generate an empty string if there is no diff" do
+        checksum = save_bucket_file("I'm the contents of a file")
+        Puppet::FileBucket::File.find("md5/#{checksum}", :diff_with => checksum).should == ''
+      end
+
+      it "should generate a proper diff if there is a diff" do
+        checksum1 = save_bucket_file("foo\nbar\nbaz")
+        checksum2 = save_bucket_file("foo\nbiz\nbaz")
+        diff = Puppet::FileBucket::File.find("md5/#{checksum1}", :diff_with => checksum2)
+        diff.should == <<HERE
+2c2
+< bar
+---
+> biz
+HERE
+      end
+
+      it "should raise an exception if the hash to diff against isn't found" do
+        checksum = save_bucket_file("whatever")
+        bogus_checksum = "d1bf072d0e2c6e20e3fbd23f022089a1"
+        lambda { Puppet::FileBucket::File.find("md5/#{checksum}", :diff_with => bogus_checksum) }.should raise_error "could not find diff_with #{bogus_checksum}"
+      end
+
+      it "should return nil if the hash to diff from isn't found" do
+        checksum = save_bucket_file("whatever")
+        bogus_checksum = "d1bf072d0e2c6e20e3fbd23f022089a1"
+        Puppet::FileBucket::File.find("md5/#{bogus_checksum}", :diff_with => checksum).should == nil
+      end
+    end
+  end
+
   describe "when initializing" do
     it "should use the filebucket settings section" do
       Puppet.settings.expects(:use).with(:filebucket)
diff --git a/spec/unit/network/http/handler_spec.rb b/spec/unit/network/http/handler_spec.rb
index 76a9c5530..cdbce41f7 100755
--- a/spec/unit/network/http/handler_spec.rb
+++ b/spec/unit/network/http/handler_spec.rb
@@ -209,6 +209,12 @@ describe Puppet::Network::HTTP::Handler do
         @handler.do_find(@irequest, @request, @response)
       end
 
+      it "should pass the result through without rendering it if the result is a string" do
+        @model_class.stubs(:find).returns "foo"
+        @handler.expects(:set_response).with(@response, "foo")
+        @handler.do_find(@irequest, @request, @response)
+      end
+
       it "should use the default status when a model find call succeeds" do
         @handler.expects(:set_response).with { |response, body, status| status.nil? }
         @handler.do_find(@irequest, @request, @response)