Merge 53863269- to master

Glyn Normington · Glyn Normington · commit 7b40cd95c46c · 2013-08-15T09:28:52.000+01:00
[Completes #53863269]
diff --git a/lib/java_buildpack/buildpack.rb b/lib/java_buildpack/buildpack.rb
@@ -107,13 +107,16 @@ def release
 
     private
 
+    GIT_DIR = File.expand_path('../../.git', File.dirname(__FILE__)).freeze
+
     COMPONENTS_CONFIG = '../../config/components.yml'.freeze
 
     LIB_DIRECTORY = '.lib'
 
     # Instances should only be constructed by this class.
     def initialize(app_dir)
       @logger = JavaBuildpack::Diagnostics::LoggerFactory.get_logger
+      Buildpack.log_git_data @logger
       Buildpack.dump_environment_variables @logger
       Buildpack.require_component_files
       components = Buildpack.components @logger
@@ -194,6 +197,15 @@ def self.jre_directory
       Pathname.new(File.expand_path('jre', File.dirname(__FILE__)))
     end
 
+    def self.log_git_data(logger)
+      # Log information about the buildpack's git repository to enable stale forks to be spotted.
+      # Call the debug method passing a parameter rather than a block so that, should the git command
+      # become inaccessible to the buildpack at some point in the future, we find out before someone
+      # happens to switch on debug logging.
+      logger.debug("git remotes: #{`git --git-dir=#{GIT_DIR} remote -v`}")
+      logger.debug("git HEAD commit: #{`git --git-dir=#{GIT_DIR} log HEAD^!`}")
+    end
+
     def self.lib_directory(app_dir)
       File.join app_dir, LIB_DIRECTORY
     end
