glance Windows support

This change will allow glance services to run on Windows, using
eventlet wsgi for API services.

This change will:
* avoid monkey patching the os module on Windows (which causes Popen
  to fail)
* avoiding unavailable signals
* avoid renaming in-use files or leaking handles
* update the check that ensures that just one scrubber process may
  run at a time. We can't rely on process names as there might be
  wrapper processes that have similar names (no she-bangs on Windows,
  so the scripts are called a bit differently). We'll use a global
  named mutex instead.

A subsequent change will leverage Windows job objects as a
replacement for process groups, also avoiding forking when spawning
workers.

At the moment, some Glance tests cannot run on Windows, which is
also covered by subsequent patches.

DocImpact

blueprint windows-support

Change-Id: I3bca69638685ceb11a1a316511ad9a298c630ad5

glance/async_/flows/convert.py

@@ -91,6 +91,7 @@ class _Convert(task.Task):
         # specified. There's no "sane" default for this
         # because the dest format may work differently depending
         # on the environment OpenStack is running in.
+        abs_file_path = file_path.split("file://")[-1]
         conversion_format = CONF.taskflow_executor.conversion_format
         if conversion_format is None:
             if not _Convert.conversion_missing_warned:
@@ -123,7 +124,8 @@ class _Convert(task.Task):
         if stderr:
             raise RuntimeError(stderr)
 
-        os.rename(dest_path, file_path.split("file://")[-1])
+        os.unlink(abs_file_path)
+        os.rename(dest_path, abs_file_path)
         return file_path
 
     def revert(self, image_id, result=None, **kwargs):

glance/async_/flows/ovf_process.py

@@ -82,6 +82,7 @@ class _OVF_Process(task.Task):
         :param file_path: Path to the OVA package
         """
 
+        file_abs_path = file_path.split("file://")[-1]
         image = self.image_repo.get(image_id)
         # Expect 'ova' as image container format for OVF_Process task
         if image.container_format == 'ova':
@@ -92,6 +93,8 @@ class _OVF_Process(task.Task):
             # the context as a short-cut.
             if image.context and image.context.is_admin:
                 extractor = OVAImageExtractor()
+                data_iter = None
+                try:
                     data_iter = self._get_ova_iter_objects(file_path)
                     disk, properties = extractor.extract(data_iter)
                     image.extra_properties.update(properties)
@@ -100,9 +103,13 @@ class _OVF_Process(task.Task):
                     dest_path = self._get_extracted_file_path(image_id)
                     with open(dest_path, 'wb') as f:
                         shutil.copyfileobj(disk, f, 4096)
+                finally:
+                    if data_iter:
+                        data_iter.close()
 
                 # Overwrite the input ova file since it is no longer needed
-                os.rename(dest_path, file_path.split("file://")[-1])
+                os.unlink(file_abs_path)
+                os.rename(dest_path, file_abs_path)
 
             else:
                 raise RuntimeError(_('OVA extract is limited to admin'))

glance/cmd/api.py

@@ -20,6 +20,10 @@
 """
 Glance API Server
 """
+
+import os
+import sys
+
 import eventlet
 # NOTE(jokke): As per the eventlet commit
 # b756447bab51046dfc6f1e0e299cc997ab343701 there's circular import happening
@@ -27,10 +31,13 @@ import eventlet
 # before calling monkey_patch(). This is solved in eventlet 0.22.0 but we
 # need to address it before that is widely used around.
 eventlet.hubs.get_hub()
-eventlet.patcher.monkey_patch()
 
-import os
+if os.name == 'nt':
-import sys
+    # eventlet monkey patching the os module causes subprocess.Popen to fail
+    # on Windows when using pipes due to missing non-blocking IO support.
+    eventlet.patcher.monkey_patch(os=False)
+else:
+    eventlet.patcher.monkey_patch()
 
 from oslo_utils import encodeutils
 

glance/cmd/registry.py

@@ -20,6 +20,10 @@
 """
 Reference implementation server for Glance Registry
 """
+
+import os
+import sys
+
 import eventlet
 # NOTE(jokke): As per the eventlet commit
 # b756447bab51046dfc6f1e0e299cc997ab343701 there's circular import happening
@@ -27,11 +31,13 @@ import eventlet
 # before calling monkey_patch(). This is solved in eventlet 0.22.0 but we
 # need to address it before that is widely used around.
 eventlet.hubs.get_hub()
-eventlet.patcher.monkey_patch()
-
-import os
-import sys
 
+if os.name == 'nt':
+    # eventlet monkey patching the os module causes subprocess.Popen to fail
+    # on Windows when using pipes due to missing non-blocking IO support.
+    eventlet.patcher.monkey_patch(os=False)
+else:
+    eventlet.patcher.monkey_patch()
 
 from oslo_utils import encodeutils
 

glance/cmd/scrubber.py

@@ -18,6 +18,10 @@
 """
 Glance Scrub Service
 """
+
+import os
+import sys
+
 import eventlet
 # NOTE(jokke): As per the eventlet commit
 # b756447bab51046dfc6f1e0e299cc997ab343701 there's circular import happening
@@ -25,11 +29,15 @@ import eventlet
 # before calling monkey_patch(). This is solved in eventlet 0.22.0 but we
 # need to address it before that is widely used around.
 eventlet.hubs.get_hub()
-eventlet.patcher.monkey_patch()
 
-import os
+if os.name == 'nt':
+    # eventlet monkey patching the os module causes subprocess.Popen to fail
+    # on Windows when using pipes due to missing non-blocking IO support.
+    eventlet.patcher.monkey_patch(os=False)
+else:
+    eventlet.patcher.monkey_patch()
+
 import subprocess
-import sys
 
 # If ../glance/__init__.py exists, add ../ to Python search path, so that
 # it will override what happens to be installed in /usr/(local/)lib/python...
@@ -40,6 +48,7 @@ if os.path.exists(os.path.join(possible_topdir, 'glance', '__init__.py')):
     sys.path.insert(0, possible_topdir)
 
 import glance_store
+from os_win import utilsfactory as os_win_utilsfactory
 from oslo_config import cfg
 from oslo_log import log as logging
 
@@ -54,10 +63,21 @@ CONF.set_default(name='use_stderr', default=True)
 
 
 def main():
+    # Used on Window, ensuring that a single scrubber can run at a time.
+    mutex = None
+    mutex_acquired = False
+
+    try:
+        if os.name == 'nt':
+            # We can't rely on process names on Windows as there may be
+            # wrappers with the same name.
+            mutex = os_win_utilsfactory.get_mutex(
+                name='Global\\glance-scrubber')
+            mutex_acquired = mutex.acquire(timeout_ms=0)
+
         CONF.register_cli_opts(scrubber.scrubber_cmd_cli_opts)
         CONF.register_opts(scrubber.scrubber_cmd_opts)
 
-    try:
         config.parse_args()
         logging.setup(CONF, 'glance')
 
@@ -65,21 +85,48 @@ def main():
         glance_store.create_stores(config.CONF)
         glance_store.verify_default_store()
 
-        app = scrubber.Scrubber(glance_store)
-
         if CONF.restore and CONF.daemon:
             sys.exit("ERROR: The restore and daemon options should not be set "
                      "together. Please use either of them in one request.")
+
+        app = scrubber.Scrubber(glance_store)
+
         if CONF.restore:
+            if os.name == 'nt':
+                scrubber_already_running = not mutex_acquired
+            else:
+                scrubber_already_running = scrubber_already_running_posix()
+
+            if scrubber_already_running:
+                already_running_msg = (
+                    "ERROR: glance-scrubber is already running. "
+                    "Please ensure that the daemon is stopped.")
+                sys.exit(already_running_msg)
+
+            app.revert_image_status(CONF.restore)
+        elif CONF.daemon:
+            server = scrubber.Daemon(CONF.wakeup_time)
+            server.start(app)
+            server.wait()
+        else:
+            app.run()
+    except (exception.ImageNotFound, exception.Conflict) as e:
+        sys.exit("ERROR: %s" % e)
+    except RuntimeError as e:
+        sys.exit("ERROR: %s" % e)
+    finally:
+        if mutex and mutex_acquired:
+            mutex.release()
+
+
+def scrubber_already_running_posix():
     # Try to check the glance-scrubber is running or not.
     # 1. Try to find the pid file if scrubber is controlled by
     #    glance-control
     # 2. Try to check the process name.
-            error_str = ("ERROR: The glance-scrubber process is running under "
-                         "daemon. Please stop it first.")
     pid_file = '/var/run/glance/glance-scrubber.pid'
     if os.path.exists(os.path.abspath(pid_file)):
-                sys.exit(error_str)
+        return True
 
     for glance_scrubber_name in ['glance-scrubber',
                                  'glance.cmd.scrubber']:
@@ -98,23 +145,14 @@ def main():
         if pids.count('\n') > 1 and str(self_pid) in pids:
             # One process is self, so if the process number is > 1, it
             # means that another glance-scrubber process is running.
-                    sys.exit(error_str)
+            return True
         elif pids.count('\n') > 0 and str(self_pid) not in pids:
             # If self is not in result and the pids number is still
             # > 0, it means that the another glance-scrubber process is
             # running.
-                    sys.exit(error_str)
+            return True
-            app.revert_image_status(CONF.restore)
+
-        elif CONF.daemon:
+    return False
-            server = scrubber.Daemon(CONF.wakeup_time)
-            server.start(app)
-            server.wait()
-        else:
-            app.run()
-    except (exception.ImageNotFound, exception.Conflict) as e:
-        sys.exit("ERROR: %s" % e)
-    except RuntimeError as e:
-        sys.exit("ERROR: %s" % e)
 
 
 if __name__ == '__main__':

glance/common/wsgi.py

@@ -495,8 +495,10 @@ class Server(object):
         try:
             # NOTE(flaper87): Make sure this process
             # runs in its own process group.
+            # NOTE(lpetrut): This isn't available on Windows, so we're going
+            # to use job objects instead.
             os.setpgid(self.pgid, self.pgid)
-        except OSError:
+        except (OSError, AttributeError):
             # NOTE(flaper87): When running glance-control,
             # (glance's functional tests, for example)
             # setpgid fails with EPERM as glance-control
@@ -508,18 +510,25 @@ class Server(object):
             # shouldn't raise any error here.
             self.pgid = 0
 
+    @staticmethod
+    def set_signal_handler(signal_name, handler):
+        # Some signals may not be available on this platform.
+        sig = getattr(signal, signal_name, None)
+        if sig is not None:
+            signal.signal(sig, handler)
+
     def hup(self, *args):
         """
         Reloads configuration files with zero down time
         """
-        signal.signal(signal.SIGHUP, signal.SIG_IGN)
+        self.set_signal_handler("SIGHUP", signal.SIG_IGN)
         raise exception.SIGHUPInterrupt
 
     def kill_children(self, *args):
         """Kills the entire process group."""
-        signal.signal(signal.SIGTERM, signal.SIG_IGN)
+        self.set_signal_handler("SIGTERM", signal.SIG_IGN)
-        signal.signal(signal.SIGINT, signal.SIG_IGN)
+        self.set_signal_handler("SIGINT", signal.SIG_IGN)
-        signal.signal(signal.SIGCHLD, signal.SIG_IGN)
+        self.set_signal_handler("SIGCHLD", signal.SIG_IGN)
         self.running = False
         os.killpg(self.pgid, signal.SIGTERM)
 
@@ -544,9 +553,9 @@ class Server(object):
             return
         else:
             LOG.info(_LI("Starting %d workers"), workers)
-            signal.signal(signal.SIGTERM, self.kill_children)
+            self.set_signal_handler("SIGTERM", self.kill_children)
-            signal.signal(signal.SIGINT, self.kill_children)
+            self.set_signal_handler("SIGINT", self.kill_children)
-            signal.signal(signal.SIGHUP, self.hup)
+            self.set_signal_handler("SIGHUP", self.hup)
             while len(self.children) < workers:
                 self.run_child()
 
@@ -655,18 +664,18 @@ class Server(object):
     def run_child(self):
         def child_hup(*args):
             """Shuts down child processes, existing requests are handled."""
-            signal.signal(signal.SIGHUP, signal.SIG_IGN)
+            self.set_signal_handler("SIGHUP", signal.SIG_IGN)
             eventlet.wsgi.is_accepting = False
             self.sock.close()
 
         pid = os.fork()
         if pid == 0:
-            signal.signal(signal.SIGHUP, child_hup)
+            self.set_signal_handler("SIGHUP", child_hup)
-            signal.signal(signal.SIGTERM, signal.SIG_DFL)
+            self.set_signal_handler("SIGTERM", signal.SIG_DFL)
             # ignore the interrupt signal to avoid a race whereby
             # a child worker receives the signal before the parent
             # and is respawned unnecessarily as a result
-            signal.signal(signal.SIGINT, signal.SIG_IGN)
+            self.set_signal_handler("SIGINT", signal.SIG_IGN)
             # The child has no need to stash the unwrapped
             # socket, and the reference prevents a clean
             # exit on sighup

glance/tests/functional/serial/test_scrubber.py

@@ -351,8 +351,7 @@ class TestScrubber(functional.FunctionalTest):
         cmd = ("%s --restore fake_image_id" % exe_cmd)
         exitcode, out, err = execute(cmd, raise_error=False)
         self.assertEqual(1, exitcode)
-        self.assertIn('The glance-scrubber process is running under daemon',
+        self.assertIn('glance-scrubber is already running', str(err))
-                      str(err))
 
         self.stop_server(self.scrubber_daemon)
 
@@ -363,7 +362,7 @@ class TestScrubber(functional.FunctionalTest):
         # Sometimes the glance-scrubber process which is setup by the
         # previous test can't be shutdown immediately, so if we get the "daemon
         # running" message we sleep and try again.
-        not_down_msg = 'The glance-scrubber process is running under daemon'
+        not_down_msg = 'glance-scrubber is already running'
         total_wait = 15
         for _ in range(total_wait):
             exitcode, out, err = func()

glance/tests/unit/async_/flows/test_convert.py

@@ -78,7 +78,8 @@ class TestImportTask(test_utils.BaseTestCase):
                     group='taskflow_executor')
         glance_store.create_stores(CONF)
 
-    def test_convert_success(self):
+    @mock.patch.object(os, 'unlink')
+    def test_convert_success(self, mock_unlink):
         image_convert = convert._Convert(self.task.task_id,
                                          self.task_type,
                                          self.img_repo)

lower-constraints.txt

@@ -61,6 +61,7 @@ openstackdocstheme==1.18.1
 os-api-ref==1.4.0
 os-client-config==1.29.0
 os-testr==1.0.0
+os-win==3.0.0
 oslo.cache==1.29.0
 oslo.concurrency==3.26.0
 oslo.config==5.2.0

releasenotes/notes/windows-support-f4aae61681dba569.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Glance services can now run on Windows.

requirements.txt

@@ -56,3 +56,5 @@ cursive>=0.2.1 # Apache-2.0
 
 # timeutils
 iso8601>=0.1.11 # MIT
+
+os-win>=3.0.0 # Apache-2.0