fix: change permissions and remove files on rmtree (#1694)

* fix: change permissions and remove files on rmtree

* fix: add `onerror` rmtreecallback docstring

samcli/commands/init/init_templates.py

@@ -17,6 +17,7 @@
 from samcli.cli.main import global_cfg
 from samcli.commands.exceptions import UserException, AppTemplateUpdateException
 from samcli.lib.utils import osutils
+from samcli.lib.utils.osutils import rmtree_callback
 from samcli.local.common.runtime_template import RUNTIME_DEP_TEMPLATE_MAPPING
 
 LOG = logging.getLogger(__name__)
@@ -164,7 +165,7 @@ def _overwrite_existing_templates(self, shared_dir, expected_path):
     def _replace_app_templates(self, temp_path, dest_path):
         try:
             LOG.debug("Removing old templates from %s", str(dest_path))
-            shutil.rmtree(dest_path)
+            shutil.rmtree(dest_path, onerror=rmtree_callback)
             LOG.debug("Copying templates from %s to %s", str(temp_path), str(dest_path))
             shutil.copytree(temp_path, dest_path, ignore=shutil.ignore_patterns("*.git"))
         except (OSError, shutil.Error):

samcli/lib/utils/osutils.py

@@ -1,17 +1,14 @@
 """
 Common OS utilities
 """
-
-import sys
+import logging
 import os
 import shutil
+import stat
+import sys
 import tempfile
-import logging
-import contextlib
-
 from contextlib import contextmanager
 
-
 LOG = logging.getLogger(__name__)
 
 
@@ -47,13 +44,25 @@ def mkdir_temp(mode=0o755, ignore_errors=False):
     finally:
         if temp_dir:
             if ignore_errors:
-                shutil.rmtree(temp_dir, False, _rmtree_callback)
+                shutil.rmtree(temp_dir, False, rmtree_callback)
             else:
                 shutil.rmtree(temp_dir)
 
 
-def _rmtree_callback(function, path, excinfo):
-    LOG.debug("rmtree failed in %s for %s, details: %s", function, path, excinfo)
+def rmtree_callback(function, path, excinfo):
+    """
+    Callback function for shutil.rmtree to change permissions on the file path, so that
+    it's delete-able incase the file path is read-only.
+    :param function: platform and implementation dependent function.
+    :param path: argument to the function that caused it to fail.
+    :param excinfo: tuple returned by sys.exc_info()
+    :return:
+    """
+    try:
+        os.chmod(path=path, mode=stat.S_IWRITE)
+        os.remove(path)
+    except OSError:
+        LOG.debug("rmtree failed in %s for %s, details: %s", function, path, excinfo)
 
 
 def stdout():
@@ -88,7 +97,7 @@ def remove(path):
             pass
 
 
-@contextlib.contextmanager
+@contextmanager
 def tempfile_platform_independent():
     # NOTE(TheSriram): Setting delete=False is specific to windows.
     # https://docs.python.org/3/library/tempfile.html#tempfile.NamedTemporaryFile