Add default Plugin.setup() method

Adding a default setup() method to the base Plugin class allows
useful plugins to be written declaratively by setting the 'files'
and 'packages' members of the subclass, e.g.:

    class FooPlugin(Plugin):
	plugin_name = 'foo'
        packages = ('foo',)
        files = ('/etc/foo.conf',)

Creates a plugin class named 'foo' that will run whenever the
'foo' package is installed or the '/etc/foo.conf' file exists.

The method calls self.add_copy_specs() with the plugin's files
list.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>

sos/plugins/__init__.py

@@ -647,10 +647,11 @@ def default_enabled(self):
         return True
 
     def setup(self):
-        """This method must be overridden to add the copy_specs, forbidden_paths,
-        and external programs to be collected at a minimum.
+        """Collect the list of files declared by the plugin. This method
+        may be overridden to add further copy_specs, forbidden_paths, and
+        external programs if required.
         """
-        pass
+        self.add_copy_specs(list(self.files))
 
     def postproc(self):
         """

sos/plugins/anacron.py

@@ -25,7 +25,4 @@ class Anacron(Plugin, RedHatPlugin, DebianPlugin, UbuntuPlugin):
     # just look for the configuration file which is common
     files = ('/etc/anacrontab',)
 
-    def setup(self):
-        self.add_copy_specs(list(self.files))
-
 # vim: et ts=4 sw=4

sos/plugins/distupgrade.py

@@ -24,8 +24,6 @@ class DistUpgrade(Plugin):
 
     files = None
 
-    def setup(self):
-        self.add_copy_specs(list(self.files))
 
 class RedHatDistUpgrade(DistUpgrade, RedHatPlugin):