Use oslo.service for launching sahara

Changes:
* use launcher for running sahara modules
* use wsgi server from oslo.service library

Change-Id: I9ba8f1e751ce9bb9b9adcebda6509107b98e2fc8

sahara/cli/sahara_all.py

@@ -57,4 +57,6 @@ def main():
     server.setup_sahara_engine()
     server.setup_auth_policy()
 
-    server.start_server(app)
+    launcher = server.get_process_launcher()
+    launcher.launch_service(server.SaharaWSGIService("sahara-all", app))
+    launcher.wait()

sahara/cli/sahara_api.py

@@ -55,4 +55,6 @@ def main():
     server.setup_sahara_api('distributed')
     server.setup_auth_policy()
 
-    server.start_server(app)
+    launcher = server.get_process_launcher()
+    api_service = server.SaharaWSGIService("sahara-api", app)
+    server.launch_api_service(launcher, api_service)

sahara/cli/sahara_engine.py

@@ -51,4 +51,6 @@ def main():
     server.setup_sahara_engine()
 
     ops_server = ops.OpsServer()
-    ops_server.start()
+    launcher = server.get_process_launcher()
+    launcher.launch_service(ops_server.get_service())
+    launcher.wait()

sahara/config.py

@@ -143,7 +143,6 @@ def list_opts():
     from sahara.utils import poll_utils
     from sahara.utils import proxy
     from sahara.utils import ssh_remote
-    from sahara.utils import wsgi
 
     return [
         (None,
@@ -161,7 +160,6 @@ def list_opts():
                          periodic.periodic_opts,
                          proxy.opts,
                          cpo.event_log_opts,
-                         wsgi.wsgi_opts,
                          base.opts,
                          heat_engine.heat_engine_opts,
                          ssh_remote.ssh_config_options)),

sahara/main.py

@@ -17,7 +17,8 @@ import os
 
 from oslo_config import cfg
 from oslo_log import log
-from oslo_service import systemd
+from oslo_service import service as oslo_service
+from oslo_service import sslutils
 from oslo_service import wsgi as oslo_wsgi
 import stevedore
 
@@ -33,7 +34,6 @@ from sahara.service import periodic
 from sahara.utils.openstack import cinder
 from sahara.utils import remote
 from sahara.utils import rpc as messaging
-from sahara.utils import wsgi
 
 LOG = log.getLogger(__name__)
 
@@ -49,7 +49,7 @@ opts = [
                default='ssh',
                help='A method for Sahara to execute commands '
                     'on VMs.'),
-    cfg.IntOpt('api_workers', default=0,
+    cfg.IntOpt('api_workers', default=1,
                help="Number of workers for Sahara API service (0 means "
                     "all-in-one-thread configuration).")
 ]
@@ -58,6 +58,13 @@ CONF = cfg.CONF
 CONF.register_opts(opts)
 
 
+class SaharaWSGIService(oslo_wsgi.Server):
+    def __init__(self, service_name, app):
+        super(SaharaWSGIService, self).__init__(
+            CONF, service_name, app, host=CONF.host, port=CONF.port,
+            use_ssl=sslutils.is_enabled(CONF))
+
+
 def setup_common(possible_topdir, service_name):
     dev_conf = os.path.join(possible_topdir,
                             'etc',
@@ -145,8 +152,10 @@ def _get_ops_driver(driver_name):
     return _load_driver('sahara.run.mode', driver_name)
 
 
-def start_server(app):
+def get_process_launcher():
-    server = wsgi.Server()
+    return oslo_service.ProcessLauncher(CONF)
-    server.start(app)
+
-    systemd.notify_once()
+
-    server.wait()
+def launch_api_service(launcher, service):
+    launcher.launch_service(service, workers=CONF.api_workers)
+    launcher.wait()

sahara/utils/rpc.py

@@ -89,9 +89,8 @@ class RPCServer(object):
             endpoints=[self],
             executor='eventlet')
 
-    def start(self):
+    def get_service(self):
-        self.__server.start()
+        return self.__server
-        self.__server.wait()
 
 
 def setup():

sahara/utils/wsgi.py

@@ -19,35 +19,17 @@
 """Utility methods for working with WSGI servers."""
 
 import datetime
-import errno
-import os
-import signal
 
-import eventlet
-from eventlet import wsgi
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_serialization import jsonutils
-from oslo_service import sslutils
 
 from sahara import exceptions
 from sahara.i18n import _
-from sahara.i18n import _LE
-from sahara.i18n import _LI
 
 LOG = logging.getLogger(__name__)
 
-wsgi_opts = [
-    cfg.IntOpt('max_header_line',
-               default=16384,
-               help="Maximum line size of message headers to be accepted. "
-                    "max_header_line may need to be increased when using "
-                    "large tokens (typically those generated by the "
-                    "Keystone v3 API with big service catalogs)."),
-]
-
 CONF = cfg.CONF
-CONF.register_opts(wsgi_opts)
 
 
 class ActionDispatcher(object):
@@ -106,113 +88,3 @@ class JSONDeserializer(TextDeserializer):
 
     def default(self, datastring):
         return {'body': self._from_json(datastring)}
-
-
-class Server(object):
-    """Server class to manage multiple WSGI sockets and applications."""
-
-    def __init__(self, threads=500):
-        eventlet.wsgi.MAX_HEADER_LINE = CONF.max_header_line
-        self.threads = threads
-        self.children = []
-        self.running = True
-
-    def start(self, application):
-        """Run a WSGI server with the given application.
-
-        :param application: The application to run in the WSGI server
-        """
-        def kill_children(*args):
-            """Kills the entire process group."""
-            LOG.error(_LE('SIGTERM received'))
-            signal.signal(signal.SIGTERM, signal.SIG_IGN)
-            self.running = False
-            os.killpg(0, signal.SIGTERM)
-
-        def hup(*args):
-            """Shuts down the server(s).
-
-            Shuts down the server(s), but allows running requests to complete
-            """
-            LOG.error(_LE('SIGHUP received'))
-            signal.signal(signal.SIGHUP, signal.SIG_IGN)
-            os.killpg(0, signal.SIGHUP)
-            signal.signal(signal.SIGHUP, hup)
-
-        self.application = application
-        self.sock = eventlet.listen((CONF.host, CONF.port), backlog=500)
-        if sslutils.is_enabled(CONF):
-            LOG.info(_LI("Using HTTPS for port %s"), CONF.port)
-            self.sock = sslutils.wrap(CONF, self.sock)
-
-        if CONF.api_workers == 0:
-            # Useful for profiling, test, debug etc.
-            self.pool = eventlet.GreenPool(size=self.threads)
-            self.pool.spawn_n(self._single_run, application, self.sock)
-            return
-
-        LOG.debug("Starting %d workers", CONF.api_workers)
-        signal.signal(signal.SIGTERM, kill_children)
-        signal.signal(signal.SIGHUP, hup)
-        while len(self.children) < CONF.api_workers:
-            self.run_child()
-
-    def wait_on_children(self):
-        while self.running:
-            try:
-                pid, status = os.wait()
-                if os.WIFEXITED(status) or os.WIFSIGNALED(status):
-                    if pid in self.children:
-                        LOG.error(_LE('Removing dead child %s'), pid)
-                        self.children.remove(pid)
-                        self.run_child()
-            except OSError as err:
-                if err.errno not in (errno.EINTR, errno.ECHILD):
-                    raise
-            except KeyboardInterrupt:
-                LOG.info(_LI('Caught keyboard interrupt. Exiting.'))
-                os.killpg(0, signal.SIGTERM)
-                break
-        eventlet.greenio.shutdown_safe(self.sock)
-        self.sock.close()
-        LOG.debug('Server exited')
-
-    def wait(self):
-        """Wait until all servers have completed running."""
-        try:
-            if self.children:
-                self.wait_on_children()
-            else:
-                self.pool.waitall()
-        except KeyboardInterrupt:
-            pass
-
-    def run_child(self):
-        pid = os.fork()
-        if pid == 0:
-            signal.signal(signal.SIGHUP, signal.SIG_DFL)
-            signal.signal(signal.SIGTERM, signal.SIG_DFL)
-            self.run_server()
-            LOG.debug('Child %d exiting normally', os.getpid())
-            return
-        else:
-            LOG.info(_LI('Started child %s'), pid)
-            self.children.append(pid)
-
-    def run_server(self):
-        """Run a WSGI server."""
-        self.pool = eventlet.GreenPool(size=self.threads)
-        wsgi.server(self.sock,
-                    self.application,
-                    custom_pool=self.pool,
-                    log=LOG,
-                    debug=False)
-        self.pool.waitall()
-
-    def _single_run(self, application, sock):
-        """Start a WSGI server in a new green thread."""
-        LOG.info(_LI("Starting single process server"))
-        eventlet.wsgi.server(sock, application,
-                             custom_pool=self.pool,
-                             log=LOG,
-                             debug=False)

tools/config/config-generator.sahara.conf

@@ -10,3 +10,4 @@ namespace = oslo.middleware.cors
 namespace = oslo.policy
 namespace = oslo.service.periodic_task
 namespace = oslo.service.sslutils
+namespace = oslo.service.wsgi