Merge "framework: Add reworked framework to repo"

1 files changed, 316 insertions, 0 deletions

diff --git a/src/ovs/ofctl.py b/src/ovs/ofctl.py
new file mode 100644
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--- /dev/null
+++ b/src/ovs/ofctl.py
@@ -0,0 +1,316 @@
+# Copyright 2015 Intel Corporation.
+#
+# 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.
+
+"""Wrapper for an OVS bridge for convenient use of ``ovs-vsctl`` and
+``ovs-ofctl`` on it.
+
+Much of this code is based on ``ovs-lib.py`` from Open Stack:
+
+https://github.com/openstack/neutron/blob/6eac1dc99124ca024d6a69b3abfa3bc69c735667/neutron/agent/linux/ovs_lib.py
+"""
+
+import os
+import logging
+import string
+
+from tools import tasks
+from conf import settings
+
+_OVS_VSCTL_BIN = os.path.join(settings.getValue('OVS_DIR'), 'utilities',
+                              'ovs-vsctl')
+_OVS_OFCTL_BIN = os.path.join(settings.getValue('OVS_DIR'), 'utilities',
+                              'ovs-ofctl')
+
+class OFBase(object):
+    """Add/remove/show datapaths using ``ovs-ofctl``.
+    """
+    def __init__(self, timeout=10):
+        """Initialise logger.
+
+        :param timeout: Timeout to be used for each command
+
+        :returns: None
+        """
+        self.logger = logging.getLogger(__name__)
+        self.timeout = timeout
+
+    # helpers
+
+    def run_vsctl(self, args, check_error=False):
+        """Run ``ovs-vsctl`` with supplied arguments.
+
+        :param args: Arguments to pass to ``ovs-vsctl``
+        :param check_error: Throw exception on error
+
+        :return: None
+        """
+        cmd = ['sudo', _OVS_VSCTL_BIN, '--timeout', str(self.timeout)] + args
+        return tasks.run_task(
+            cmd, self.logger, 'Running ovs-vsctl...', check_error)
+
+    # datapath management
+
+    def add_br(self, br_name='br0'):
+        """Add datapath.
+
+        :param br_name: Name of bridge
+
+        :return: Instance of :class OFBridge:
+        """
+        self.logger.debug('add bridge')
+        self.run_vsctl(['add-br', br_name])
+
+        return OFBridge(br_name, self.timeout)
+
+    def del_br(self, br_name='br0'):
+        """Delete datapath.
+
+        :param br_name: Name of bridge
+
+        :return: None
+        """
+        self.logger.debug('delete bridge')
+        self.run_vsctl(['del-br', br_name])
+
+
+class OFBridge(OFBase):
+    """Control a bridge instance using ``ovs-vsctl`` and ``ovs-ofctl``.
+    """
+    def __init__(self, br_name='br0', timeout=10):
+        """Initialise bridge.
+
+        :param br_name: Bridge name
+        :param timeout: Timeout to be used for each command
+
+        :returns: None
+        """
+        super(OFBridge, self).__init__(timeout)
+        self.br_name = br_name
+        self._ports = {}
+
+    # context manager
+
+    def __enter__(self):
+        """Create datapath
+
+        :returns: self
+        """
+        return self
+
+    def __exit__(self, type_, value, traceback):
+        """Remove datapath.
+        """
+        if not traceback:
+            self.destroy()
+
+    # helpers
+
+    def run_ofctl(self, args, check_error=False):
+        """Run ``ovs-ofctl`` with supplied arguments.
+
+        :param args: Arguments to pass to ``ovs-ofctl``
+        :param check_error: Throw exception on error
+
+        :return: None
+        """
+        cmd = ['sudo', _OVS_OFCTL_BIN, '--timeout', str(self.timeout)] + args
+        return tasks.run_task(
+            cmd, self.logger, 'Running ovs-ofctl...', check_error)
+
+    def create(self):
+        """Create bridge.
+        """
+        self.logger.debug('create bridge')
+        self.add_br(self.br_name)
+
+    def destroy(self):
+        """Destroy bridge.
+        """
+        self.logger.debug('destroy bridge')
+        self.del_br(self.br_name)
+
+    def reset(self):
+        """Reset bridge.
+        """
+        self.logger.debug('reset bridge')
+        self.destroy()
+        self.create()
+
+    # port management
+
+    def add_port(self, port_name, params):
+        """Add port to bridge.
+
+        :param port_name: Name of port
+        :param params: Additional list of parameters to add-port
+
+        :return: OpenFlow port number for the port
+        """
+        self.logger.debug('add port')
+        self.run_vsctl(['add-port', self.br_name, port_name]+params)
+
+        # This is how port number allocation works currently
+        # This possibly will not work correctly if there are port deletions
+        # in between
+        of_port = len(self._ports) + 1
+        self._ports[port_name] = (of_port, params)
+        return of_port
+
+    def del_port(self, port_name):
+        """Remove port from bridge.
+
+        :param port_name: Name of port
+
+        :return: None
+        """
+        self.logger.debug('delete port')
+        self.run_vsctl(['del-port', self.br_name, port_name])
+        self._ports.pop(port_name)
+
+    def set_db_attribute(self, table_name, record, column, value):
+        """Set database attribute.
+
+        :param table_name: Name of table
+        :param record: Name of record
+        :param column: Name of column
+        :param value: Value to set
+
+        :return: None
+        """
+        self.logger.debug('set attribute')
+        self.run_vsctl(['set', table_name, record, '%s=%s' % (column, value)])
+
+    def get_ports(self):
+        """Get the ports of this bridge
+
+        Structure of the returned ports dictionary is
+        'portname': (openflow_port_number, extra_parameters)
+
+        Example:
+        ports = {
+            'dpdkport0':
+                (1, ['--', 'set', 'Interface', 'dpdkport0', 'type=dpdk']),
+            'dpdkvhostport0':
+                (2, ['--', 'set', 'Interface', 'dpdkvhostport0',
+                     'type=dpdkvhost'])
+        }
+
+        :return: Dictionary of ports
+        """
+        return self._ports
+
+    def clear_db_attribute(self, table_name, record, column):
+        """Clear database attribute.
+
+        :param table_name: Name of table
+        :param record: Name of record
+        :param column: Name of column
+
+        :return: None
+        """
+        self.logger.debug('clear attribute')
+        self.run_vsctl(['clear', table_name, record, column])
+
+    # flow mangement
+
+    def add_flow(self, flow):
+        """Add flow to bridge.
+
+        :param flow: Flow description as a dictionary
+        For flow dictionary structure, see function flow_key
+
+        :return: None
+        """
+        if not flow.get('actions'):
+            self.logger.error('add flow requires actions')
+            return
+
+        self.logger.debug('add flow')
+        _flow_key = flow_key(flow)
+        self.logger.debug('key : %s', _flow_key)
+        self.run_ofctl(['add-flow', self.br_name, _flow_key])
+
+    def del_flow(self, flow):
+        """Delete flow from bridge.
+
+        :param flow: Flow description as a dictionary
+        For flow dictionary structure, see function flow_key
+        flow=None will delete all flows
+
+        :return: None
+        """
+        self.logger.debug('delete flow')
+        _flow_key = flow_key(flow)
+        self.logger.debug('key : %s', _flow_key)
+        self.run_ofctl(['del-flows', self.br_name, _flow_key])
+
+    def del_flows(self):
+        """Delete all flows from bridge.
+        """
+        self.logger.debug('delete flows')
+        self.run_ofctl(['del-flows', self.br_name])
+
+    def dump_flows(self):
+        """Dump all flows from bridge.
+        """
+        self.logger.debug('dump flows')
+        self.run_ofctl(['dump-flows', self.br_name])
+
+#
+# helper functions
+#
+
+def flow_key(flow):
+    """Model a flow key string for ``ovs-ofctl``.
+
+    Syntax taken from ``ovs-ofctl`` manpages:
+        http://openvswitch.org/cgi-bin/ovsman.cgi?page=utilities%2Fovs-ofctl.8
+
+    Example flow dictionary:
+    flow = {
+        'in_port': '1',
+        'idle_timeout': '0',
+        'actions': ['output:3']
+    }
+
+    :param flow: Flow description as a dictionary
+
+    :return: String
+    :rtype: str
+    """
+    _flow_add_key = string.Template('${fields},action=${actions}')
+    _flow_del_key = string.Template('${fields}')
+
+    field_params = []
+
+    user_params = (x for x in list(flow.items()) if x[0] != 'actions')
+    for (key, default) in user_params:
+        field_params.append('%(field)s=%(value)s' %
+                            {'field': key, 'value': default})
+
+    field_params = ','.join(field_params)
+
+    _flow_key_param = {
+        'fields': field_params,
+    }
+
+    # no actions == delete key
+    if 'actions' in flow:
+        _flow_key_param['actions'] = ','.join(flow['actions'])
+
+        flow_str = _flow_add_key.substitute(_flow_key_param)
+    else:
+        flow_str = _flow_del_key.substitute(_flow_key_param)
+
+    return flow_str