build: review of file/dir removal

slapos/recipe/build/__init__.py

@@ -24,6 +24,7 @@
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #
 ##############################################################################
+import errno
 import logging
 import os
 from platform import uname
@@ -121,6 +122,14 @@ def guessOperatingSystem():
   assert target, 'Unknown architecture'
   return target
 
+def rmtree(path):
+  try:
+    os.remove(path)
+  except OSError, e:
+    if e.errno != errno.EISDIR:
+      raise
+    shutil.rmtree(path)
+
 TRUE_LIST = ('y', 'on', 'yes', 'true', '1')
 
 class Script:
@@ -189,14 +198,14 @@ class Script:
         hash_name=True, cache=self.buildout['buildout'].get('download-cache'))
     path, is_temp = download(url, md5sum=md5sum)
     if is_temp:
-      self.cleanup_file_list.append(path)
+      self.cleanup_list.append(path)
     return path
 
   def extract(self, path):
     extract_dir = tempfile.mkdtemp(self.name)
     self.logger.debug('Created working directory %r' % extract_dir)
     setuptools.archive_util.unpack_archive(path, extract_dir)
-    self.cleanup_dir_list.append(extract_dir)
+    self.cleanup_list.append(extract_dir)
     return extract_dir
 
   def pipeCommand(self, command_list_list, *args, **kwargs):
@@ -252,11 +261,12 @@ class Script:
       raise error
     return True
 
+  cleanup_dir_list = cleanup_file_list = property(
+    lambda self: self.cleanup_list)
   script = 'raise NotImplementedError'
 
   def __init__(self, buildout, name, options):
-    self.cleanup_dir_list = []
-    self.cleanup_file_list = []
+    self.cleanup_list = []
     self.options = options
     self.buildout = buildout
     self.name = name
@@ -308,36 +318,26 @@ class Script:
     return env
 
   def install(self):
-    try:
-      if os.path.exists(self.options['location']):
-        self.cleanup_dir_list.append(self.options['location'])
-        raise shutil.Error('Directory %s already exists' % 
-            self.options['location'])
+    location = self.options['location']
+    if os.path.lexists(location):
+      self.logger.warning('Removing already existing path %r', location)
+      rmtree(location)
     env = self.getEnvironment() # env is used in script exec'ed below
-      exec self.options['script']
     try:
-        self._checkPromise('slapos_promise', self.options['location'])
-      except Exception:
-        if os.path.exists(self.options['location']):
-          self.cleanup_dir_list.append(self.options['location'])
+      exec self.options['script']
+      self._checkPromise('slapos_promise', location)
+    except:
+      self.cleanup_list.append(location)
       raise
     finally:
-      for d in self.cleanup_dir_list:
-        if os.path.exists(d):
-          if not self.keep_on_error:
-            self.logger.debug('Cleanup directory %r' % d)
-            shutil.rmtree(d)
-          else:
-            self.logger.info('Left directory %r as requested' % d)
-      for f in self.cleanup_file_list:
-        if os.path.exists(f):
-          if not self.keep_on_error:
-            self.logger.debug('Cleanup file %r' % f)
-            os.unlink(f)
+      for path in self.cleanup_list:
+        if os.path.lexists(path):
+          if self.keep_on_error:
+            self.logger.info('Left %r as requested', path)
           else:
-            self.logger.info('Left file %r as requested' % f)
-
-    return [self.options['location']]
+            self.logger.debug('Removing %r', path)
+            rmtree(path)
+    return [location]
 
   def update(self):
     pass