Implement client and server framework of FlexVolume driver

Take the cinder driver for example which the client and server
framework to implement each interfaces, such as 'is_attached'

Change-Id: Ie4e7de13d0ca5f145161a5ebeb64bcead12108dc
reference: https://review.openstack.org/#/c/474038/

fuxi_kubernetes/cmd/driver_server.py

@@ -12,6 +12,20 @@
 
 """Start server of FlexVolume driver"""
 
+from oslo_log import log as logging
+import sys
+
+from fuxi_kubernetes.common import config
+from fuxi_kubernetes.common import constants
+from fuxi_kubernetes.flex_volume_drivers.server import controller
+
 
 def main():
-    raise NotImplemented()
+    config.init(sys.argv[1:])
+    logging.setup(config.CONF, 'fuxi-kubernetes')
+
+    controller.init_volume_drivers()
+    controller.start(
+        constants.LOCAL_HOST,
+        config.CONF[config.flexvolume_driver_group.name].driver_server_port,
+        debug=config.CONF.debug, threaded=True)

fuxi_kubernetes/common/config.py

@@ -11,8 +11,11 @@
 # under the License.
 
 from oslo_config import cfg
+from oslo_log import log as logging
 
+from fuxi_kubernetes.common import constants
 from fuxi_kubernetes.i18n import _
+from fuxi_kubernetes.version import version_info
 
 
 flexvolume_driver_group = cfg.OptGroup(
@@ -27,8 +30,18 @@ flexvolume_driver_opts = [
     cfg.IntOpt('driver_server_port',
                default=7878,
                help=_('Port for the server of FlexVolume driver.')),
+    cfg.StrOpt('host_platform',
+               default='baremetal',
+               help=_('The platform on which FlexVolume driver runs. '
+                      'Optional values are: baremetal')),
 ]
 
 
 CONF = cfg.CONF
+logging.register_options(CONF)
 CONF.register_opts(flexvolume_driver_opts, flexvolume_driver_group.name)
+
+
+def init(args, **kwargs):
+    cfg.CONF(args=args, project=constants.PROJECT_NAME,
+             version=version_info.release_string(), **kwargs)

fuxi_kubernetes/common/constants.py

@@ -13,6 +13,7 @@
 
 PROJECT_NAME = 'fuxi-kubernetes'
 
+LOCAL_HOST = '0.0.0.0'
 
 VOLUME_DRIVER_CMD = (
     CMD_INIT,
@@ -66,3 +67,42 @@ VOLUME_DRIVER_CMD_RESULT_STATUS = (
     'Failed',
     'Not supported',
 )
+
+
+VOLUME_DRIVER_TYPE = (
+    VOLUME_DRIVER_CINDER,
+    VOLUME_DRIVER_MANICLA,
+) = (
+    'Cinder',
+    'Manila'
+)
+
+
+VOLUME_DRIVER_SERVER_API = (
+    SERVER_API_IS_ATTACHED,
+    SERVER_API_ATTACH,
+    SERVER_API_WAIT_FOR_ATTACH,
+    SERVER_API_MOUNT_DEVICE,
+    SERVER_API_DETACH,
+    SERVER_API_WAIT_FOR_DETACH,
+    SERVER_API_UNMOUNT_DEVICE,
+    SERVER_API_MOUNT,
+    SERVER_API_UNMOUNT
+) = (
+    '/VolumeDriver.is_attached',
+    '/VolumeDriver.attach',
+    '/VolumeDriver.wait_for_attach',
+    '/VolumeDriver.mount_device',
+    '/VolumeDriver.detach',
+    '/VolumeDriver.wait_for_detach',
+    '/VolumeDriver.unmount_device',
+    '/VolumeDriver.mount',
+    '/VolumeDriver.unmount',
+)
+
+
+CINDER_VOLUME_ATTR_KEY = (
+    CINDER_VOLUME_ATTR_VOLUME_ID,
+) = (
+    'VolumeID',
+)

fuxi_kubernetes/exceptions.py

@@ -19,3 +19,9 @@ class InvalidVolumeDriverCmdParameter(FuxiKubernetesException):
     def __init__(self, reason):
         super(InvalidVolumeDriverCmdParameter, self).__init__(
             "Invalid FlexVolume driver cmd parameter, reason:%s" % reason)
+
+
+class LoadVolumeDriverException(FuxiKubernetesException):
+    def __init__(self, reason):
+        super(LoadVolumeDriverException, self).__init__(
+            "Load volume driver failed, reason: %s" % reason)

fuxi_kubernetes/flex_volume_drivers/drivers/base.py

@@ -11,6 +11,7 @@
 # under the License.
 
 from oslo_serialization import jsonutils
+import requests
 
 from fuxi_kubernetes.common import constants
 from fuxi_kubernetes import exceptions
@@ -35,6 +36,10 @@ class BaseVolumeDriver(object):
 
     default_result = Result(status=constants.STATUS_NOT_SUPPORT)
 
+    def __init__(self):
+        self._driver_server_port = ''
+        self._driver_name = ''
+
     def init(self):
         return Result(status=constants.STATUS_SUCCESS)
 
@@ -68,14 +73,40 @@ class BaseVolumeDriver(object):
     def unmount(self, mount_dir):
         return self.default_result
 
+    def _request_server(self, api, data):
+        def _send_and_receive():
+            try:
+                url = 'http://%(ip)s:%(port)d%(api)s' % {
+                    'ip': constants.LOCAL_HOST,
+                    'port': self._driver_server_port,
+                    'api': api}
+                data['driver'] = self._driver_name
+                response = requests.post(url, json=data)
+                if not response.ok:
+                    return False, response.text
+
+                return True, response.json()
+
+            except Exception as ex:
+                return (False,
+                        'During request to server, '
+                        'threw exception:(%s)' % str(ex))
+
+        ret, info = _send_and_receive()
+        if ret:
+            return Result(**info)
+        return Result(status=constants.STATUS_FAILURE, message=info)
+
     def __call__(self, argv):
-        if not argv:
+        if not argv or len(argv) < 2:
             return self.default_result
 
-        cmd = argv[0]
+        cmd = argv[1]
         if cmd not in constants.VOLUME_DRIVER_CMD:
             return self.default_result
-        argv = argv[1:]
+
+        self._driver_server_port = int(argv[0])
+        argv = argv[2:]
 
         cmd_info = self._get_cmd_info(cmd)
         if len(argv) != cmd_info['required_params_num']:

fuxi_kubernetes/flex_volume_drivers/drivers/cinder/cinder.py

@@ -10,6 +10,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from fuxi_kubernetes.common import constants
 from fuxi_kubernetes.flex_volume_drivers.drivers import base
 
 
@@ -17,4 +18,12 @@ class DriverCinder(base.BaseVolumeDriver):
     # TODO(zengchen): implement it.
 
     def __init__(self):
-        raise NotImplemented()
+        super(DriverCinder, self).__init__()
+        self._driver_name = constants.VOLUME_DRIVER_CINDER
+
+    def is_attached(self, host_name, **kwargs):
+        return self._request_server(
+            constants.SERVER_API_IS_ATTACHED,
+            {'host_name': host_name,
+             'volume_id': kwargs.get(constants.CINDER_VOLUME_ATTR_VOLUME_ID)}
+        )

fuxi_kubernetes/flex_volume_drivers/drivers/cinder/cinder.sh

@@ -43,7 +43,9 @@ if [ $# -lt 1 ]; then
     usage
 fi
 
-out=$(fuxi-k8s-volume-driver-cinder "$@")
+config_file=/etc/fuxi-kubernetes/fuxi_kubernetes.conf
+port=$(grep driver_server_port $config_file | awk '{print $NF}')
+out=$(fuxi-k8s-volume-driver-cinder $port "$@")
 code=$?
 if [ $code -eq 0 ]; then
     log "$out"

fuxi_kubernetes/flex_volume_drivers/server/cinder/cinder.py

@@ -0,0 +1,27 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+
+class ServerCinder(object):
+    # TODO(zengchen): implement all the interface of driver, such as
+    # is_attached, attach, detach, mount, unmount etc.
+
+    def __init__(self, host_platform):
+        self._cinder_client = None
+        self._host = None
+
+    def is_attached(self, volume_id, host_name, **kwargs):
+        return False
+
+    @classmethod
+    def is_support_host_platform(cls, host_platform):
+        return True

fuxi_kubernetes/flex_volume_drivers/server/controller.py

@@ -12,4 +12,66 @@
 
 """Server of FlexVolume driver"""
 
-# TODO(zengchen): implement it.
+import flask
+import functools
+from oslo_log import log as logging
+from stevedore import extension
+
+from fuxi_kubernetes.common import config
+from fuxi_kubernetes.common import constants
+from fuxi_kubernetes import exceptions
+from fuxi_kubernetes.flex_volume_drivers.drivers import base
+
+LOG = logging.getLogger(__name__)
+
+APP = flask.Flask(__name__)
+
+
+def start(host=None, port=None, debug=None, **options):
+    APP.run(host, port, debug, **options)
+
+
+def init_volume_drivers():
+    mgr = extension.ExtensionManager(
+        namespace='flex_volume_drivers.server',
+    )
+    host_platform = config.CONF[
+        config.flexvolume_driver_group.name].host_platform
+    APP.volume_drivers = {
+        e.name: e.plugin(host_platform)
+        for e in mgr
+        if e.plugin.is_support_host_platform(host_platform)
+    }
+
+    if not APP.volume_drivers:
+        raise exceptions.LoadVolumeDriverException('No driver is loaded')
+
+
+def api_wrapper(f):
+    def _response(ret, info):
+        if ret:
+            info['status'] = constants.STATUS_SUCCESS
+        else:
+            info = {'status': constants.STATUS_FAILURE, 'message': info}
+        return flask.jsonify(base.Result(**info)())
+
+    @functools.wraps(f)
+    def wrapper(*args, **kwargs):
+        data = flask.request.get_json(force=True)
+        driver = APP.volume_drivers.get(data.get('driver'))
+        if not driver:
+            return _response(
+                False, 'Unknow FlexVolume driver:%s' % data.get('driver'))
+
+        try:
+            return _response(True, f(driver, data))
+        except Exception as ex:
+            return _response(False, str(ex))
+
+    return wrapper
+
+
+@APP.route(constants.SERVER_API_IS_ATTACHED, methods=['POST'])
+@api_wrapper
+def is_attached(driver=None, param=None):
+    return {'attached': driver.is_attached(**param)}

fuxi_kubernetes/opts.py

@@ -15,6 +15,7 @@ __all__ = [
 ]
 
 import itertools
+from oslo_log import _options
 
 from fuxi_kubernetes.common import config
 
@@ -22,6 +23,9 @@ from fuxi_kubernetes.common import config
 def list_fuxi_k8s_opts():
 
     return [
+        ('DEFAULT',
+         itertools.chain(_options.list_opts()[0][1],)),
+
         (config.flexvolume_driver_group.name,
          itertools.chain(config.flexvolume_driver_opts,)),
     ]

fuxi_kubernetes/tests/unit/base.py

@@ -1,6 +1,3 @@
-# Copyright 2010-2011 OpenStack Foundation
-# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
-#
 # Licensed under the Apache License, Version 2.0 (the "License"); you may
 # not use this file except in compliance with the License. You may obtain
 # a copy of the License at

fuxi_kubernetes/tests/unit/drivers/test_base_volume_driver.py

@@ -30,6 +30,6 @@ class TestBaseVolumeDriver(base.TestCase):
                          self._driver(['abc']).status)
 
     def test_load_json_fail(self):
-        r = self._driver(['attach', 'abc', 'abc'])
+        r = self._driver(['123', 'attach', 'abc', 'abc'])
         self.assertEqual(constants.STATUS_FAILURE, r.status)
         self.assertIn('can not load json parameter', r.message)

fuxi_kubernetes/version.py

@@ -0,0 +1,15 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import pbr.version
+
+version_info = pbr.version.VersionInfo('fuxi-kubernetes')

requirements.txt

@@ -4,3 +4,5 @@
 
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 oslo.serialization>=1.10.0 # Apache-2.0
+stevedore>=1.20.0 # Apache-2.0
+Flask!=0.11,<1.0,>=0.10 # BSD

setup.cfg

@@ -30,6 +30,9 @@ console_scripts =
     fuxi-k8s-volume-driver-cinder = fuxi_kubernetes.cmd.cinder:main
     fuxi-k8s-volume-driver-server = fuxi_kubernetes.cmd.driver_server:main
 
+flex_volume_drivers.server =
+    Cinder = fuxi_kubernetes.flex_volume_drivers.server.cinder.cinder:ServerCinder
+
 [build_sphinx]
 source-dir = doc/source
 build-dir = doc/build

setup.py

@@ -1,5 +1,3 @@
-# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
-#
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at