ContainerManagerService (#35)

* storage: StorageService no longer handles container work.

* containermgr-service: Added the new container maanger service.

This service owns container management functions such as registering a
node to a container manager. It follows a similar mechanic to the
StorageService in that it is configurable to work with different backend
systems using a handler plugin pattern.

* containermgr-service: Build and install additions.

* fixup! containermgr-service: Added the new container maanger service.

conf/containermgr.conf

@@ -0,0 +1,7 @@
+{
+  "container_handlers": [{
+      "name": "OpenshiftA1",
+      "handler": "commissaire.containermgr.kubernetes",
+      "server_url": "http://192.168.152.102:8080/"
+    }]
+}

conf/systemd/commissaire-containermgr.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=Commissaire Container Manager Service
+Documentation=https://commissaire.readthedocs.io/
+After=network.target
+
+[Service]
+ExecStart=/usr/bin/commissaire-containermgr-service -c /etc/commisasire/containermgr.conf
+PIDFile=/var/run/commissaire-containermgr-service.pid
+Type=simple
+
+[Install]
+WantedBy=multi-user.target

setup.py

@@ -68,6 +68,8 @@ def extract_requirements(filename):
              'commissaire_service.storage:main'),
             ('commissaire-clusterexec-service = '
              'commissaire_service.clusterexec:main'),
+            ('commissaire-containermgr-service = '
+             'commissaire_service.containermgr:main'),
             ('commissaire-investigator-service = '
              'commissaire_service.investigator:main'),
             ('commissaire-watcher-service = '

src/commissaire_service/containermgr/__init__.py

@@ -0,0 +1,256 @@
+# Copyright (C) 2016  Red Hat, Inc
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import importlib
+
+from commissaire.containermgr import ContainerManagerError
+from commissaire.util.config import ConfigurationError, read_config_file
+
+from commissaire_service.service import CommissaireService
+from commissaire_service.containermgr.containerhandlermanager import (
+    ContainerHandlerManager)
+
+
+class ContainerManagerService(CommissaireService):
+    """
+    Provides access to Container Managers.
+    """
+
+    def __init__(self, exchange_name, connection_url, config_file=None):
+        """
+        Creates a new ContainerManagerService and sets up ContainerHandler
+        instances according to the config_file.  If config_file is omitted,
+        it will try the default location (/etc/commissaire/commissaire.conf).
+
+        :param exchange_name: Name of the topic exchange
+        :type exchange_name: str
+        :param connection_url: Kombu connection URL
+        :type connection_url: str
+        :param config_file: Optional configuration file path
+        :type config_file: str or None
+        """
+        queue_kwargs = [{
+            'name': 'containermgr',
+            'routing_key': 'container.*',
+            'exclusive': False,
+        }]
+        super().__init__(exchange_name, connection_url, queue_kwargs)
+        self._manager = ContainerHandlerManager()
+
+        config_data = read_config_file(config_file)
+        container_handlers = config_data.get('container_handlers', [])
+
+        if len(container_handlers) == 0:
+            self.logger.info('No ContainerManagerHandlers were provided.')
+        for config in container_handlers:
+            self.register(config)
+
+    def register(self, config):
+        """
+        Registers a new container handler type after extracting and validating
+        information required for registration from the configuration data.
+
+        :param config: A configuration dictionary
+        :type config: dict
+        """
+        if type(config) is not dict:
+            raise ConfigurationError(
+                'Store handler format must be a JSON object, got a '
+                '{} instead: {}'.format(type(config).__name__, config))
+
+        # Import the handler class.
+        try:
+            module_name = config.pop('handler')
+        except KeyError as error:
+            raise ConfigurationError(
+                'Container handler configuration missing "{}" key: '
+                '{}'.format(error, config))
+        try:
+            module = importlib.import_module(module_name)
+            handler_type = getattr(module, 'ContainerHandler')
+        except ImportError:
+            raise ConfigurationError(
+                'Invalid container handler module name: {}'.format(
+                    module_name))
+
+        self._manager.register(handler_type, config)
+
+    def on_list_handlers(self, message):
+        """
+        Handler for the "container.list_handlers" routing key.
+
+        Returns a list of registered container handlers as dictionaries.
+        Each dictionary contains the following:
+
+           'name'         : The name of the container handler
+           'handler_type' : Type type of the container handler
+           'config'       : Dictionary of configuration values
+
+        :param message: A message instance
+        :type message: kombu.message.Message
+        """
+        result = []
+        for name, handler in self._manager.handlers.items():
+            result.append({
+                'name': name,
+                'handler_type': handler.__class__.__name__,
+            })
+        return result
+
+    def on_node_registered(self, message, container_handler_name, address):
+        """
+        Checks if a node is registered to a specific container manager.
+
+        :param message: A message instance
+        :type message: kombu.message.Message
+        :param container_handler_name: Name of the ContainerHandler to use.
+        :type container_handler_name: str
+        :param address: Address of the node
+        :type address: str
+        :returns: Whether the node is registered
+        :rtype: bool
+        """
+        return self._node_operation(
+            container_handler_name, 'node_registered', address)
+
+    def on_register_node(self, message, container_handler_name, address):
+        """
+        Registers a node to a container manager.
+
+        :param message: A message instance
+        :type message: kombu.message.Message
+        :param container_handler_name: Name of the ContainerHandler to use.
+        :type container_handler_name: str
+        :param address: Address of the node
+        :type address: str
+        :returns: Whether the node is registered
+        :rtype: bool
+        """
+        return self._node_operation(
+            container_handler_name, 'register_node', address)
+
+    def on_remove_node(self, message, container_handler_name, address):
+        """
+        Removes a node from a container manager.
+
+        :param message: A message instance
+        :type message: kombu.message.Message
+        :param container_handler_name: Name of the ContainerHandler to use.
+        :type container_handler_name: str
+        :param address: Address of the node
+        :type address: str
+        :returns: Whether the node is registered
+        :rtype: bool
+        """
+        return self._node_operation(
+            container_handler_name, 'remove_node', address)
+
+    def _node_operation(self, container_handler_name, method, address):
+        """
+        Common code for getting node information.
+
+        :param container_handler_name: Name of the ContainerHandler to use.
+        :type container_handler_name: str
+        :param method: The containermgr method to call.
+        :type method: str
+        :param address: Address of the node
+        :type address: str
+        :returns: Whether the node is registered
+        :rtype: bool
+        """
+        try:
+            container_handler = self._manager.handlers[container_handler_name]
+            result = getattr(container_handler, method).__call__(address)
+
+            self.logger.info(
+                '{} called for {} via the container manager {}'.format(
+                    method, address, container_handler_name))
+            self.logger.debug('Result: {}'.format(result))
+
+            if bool(result):
+                return result
+
+        except ContainerManagerError as error:
+            self.logger.info('{} raised ContainerManagerError: {}'.format(
+                error))
+        except KeyError:
+            self.logger.error('ContainerHandler {} does not exist.'.format(
+                container_handler_name))
+        except Exception as error:
+            self.logger.error(
+                'Unexpected error while attempting {} for node "{}" with '
+                'containermgr "{}". {}: {}'.format(
+                    method, address, container_handler_name,
+                    error.__class__.__name__, error))
+
+        return False
+
+    def on_get_node_status(self, message, container_handler_name, address):
+        """
+        Gets a nodes status from the container manager.
+
+        :param message: A message instance
+        :type message: kombu.message.Message
+        :param container_handler_name: Name of the ContainerHandler to use.
+        :type container_handler_name: str
+        :param address: Address of the node
+        :type address: str
+        :returns: Status of the node according to the container manager.
+        :rtype: dict
+        """
+        result = self._node_operation(
+            container_handler_name, 'get_node_status', address)
+        if result is False:
+            error = 'No status available for node {}'.format(address)
+            self.logger.error(result)
+            raise Exception(error)
+        return result
+
+
+def main():  # pragma: no cover
+    """
+    Main entry point.
+    """
+    import argparse
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '-c', '--config', type=str,
+        help='Configuration file to use.')
+    parser.add_argument(
+        '--bus-exchange', type=str, default='commissaire',
+        help='Message bus exchange name.')
+    parser.add_argument(
+        '--bus-uri', type=str, metavar='BUS_URI',
+        default='redis://127.0.0.1:6379/',  # FIXME: Remove before release
+        help=(
+            'Message bus connection URI. See:'
+            'http://kombu.readthedocs.io/en/latest/userguide/connections.html')
+    )
+
+    args = parser.parse_args()
+
+    try:
+        service = ContainerManagerService(
+            exchange_name=args.bus_exchange,
+            connection_url=args.bus_uri,
+            config_file=args.config)
+        service.run()
+    except KeyboardInterrupt:
+        pass
+
+
+if __name__ == '__main__':  # pragma: no cover
+    main()

src/commissaire_service/containermgr/containerhandlermanager.py

@@ -0,0 +1,57 @@
+# Copyright (C) 2016  Red Hat, Inc
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import logging
+
+
+class ContainerHandlerManager(object):
+    """
+    Configures ContainerHandler instances and routes storage requests to
+    the appropriate handler.
+    """
+
+    def __init__(self):
+        """
+        Creates a new ContainerHandlerManager instance.
+        """
+        self._handlers = {}
+        self.logger = logging.getLogger('containermgr')
+        self.logger.setLevel(logging.DEBUG)
+
+    def register(self, handler_type, config):
+        """
+        Registers a ContainerHandler for use in remote calls.
+
+        :param handler_type: A class derived from ContainerHandler
+        :type handler_type: type
+        :param config: Configuration parameters for the handler
+        :type config: dict
+        """
+        handler_type.check_config(config)
+        self._handlers[config['name']] = handler_type(config)
+        self.logger.info('Registered container handler {}'.format(
+            config['name']))
+        self.logger.debug('{}: {}'.format(
+            self._handlers[config['name']], config))
+
+    @property
+    def handlers(self):
+        """
+        Returns all configured container manager instances.
+
+        :returns: dict of container managers
+        :rtype: dict
+        """
+        return self._handlers

src/commissaire_service/storage/__init__.py

@@ -17,8 +17,6 @@
 import importlib
 import json
 
-from time import sleep
-
 import commissaire.models as models
 
 from commissaire import constants as C
@@ -230,41 +228,6 @@ def on_list_store_handlers(self, message):
             })
         return result
 
-    def on_node_registered(self, message, cluster_type, address):
-        """
-        Checks if a cluster node at the given address is registered on a
-        cluster of the given type.  This method may take several seconds
-        to complete if the cluster node is unresponsive, as it retries a
-        few times with a sleep delay.
-
-        :param message: A message instance
-        :type message: kombu.message.Message
-        :param cluster_type: A cluster type constant
-        :type cluster_type: str
-        :param address: Address of the cluster node
-        :type address: str
-        :returns: Whether the node is registered
-        :rtype: bool
-        """
-        for con_mgr in self._manager.list_container_managers(cluster_type):
-            # Try 3 times waiting 5 seconds each time before giving up.
-            for attempt in range(3):
-                if con_mgr.node_registered(address):
-                    self.logger.info(
-                        '{} has been registered with the '
-                        'container manager'.format(address))
-                    return True
-                if attempt == 2:
-                    self.logger.warn(
-                        'Could not register with the container manager')
-                    return False
-                self.logger.debug(
-                    '{} has not been registered with the container '
-                    'manager. Checking again in 5 seconds...'.format(
-                        address))
-                sleep(5)
-        return False
-
 
 def main():  # pragma: no cover
     """