Add topology_shuffler

JIRA: SFC-63

This module will be used to configure the assignment of endpoints and
VNFs to compute hosts dynamically

Change-Id: Ie778b52796c76d829ccb3d49e1c9bc7f5e7c7b47
Signed-off-by: George Paraskevopoulos <geopar@intracom-telecom.com>

1 files changed, 151 insertions, 0 deletions

diff --git a/sfc/lib/topology_shuffler.py b/sfc/lib/topology_shuffler.py
new file mode 100644
index 00000000..ccabe427
--- /dev/null
+++ b/sfc/lib/topology_shuffler.py
@@ -0,0 +1,151 @@
+import datetime
+import random
+import functest.utils.openstack_utils as os_utils
+import functest.utils.functest_logger as ft_logger
+
+
+logger = ft_logger.Logger(__name__).getLogger()
+
+# The possible topologies we are testing
+TOPOLOGIES = [
+    {
+        'id': 'CLIENT_VNF_SAME_HOST',
+        'description': '''
+        Client instance and vnfs are are on the same
+        compute host. Server instance is on a different host
+        '''
+    },
+    {
+        'id': 'CLIENT_SERVER_SAME_HOST',
+        'description': '''
+        Client instance and server instance are on the same
+        compute host. All VNFs are on a different host.
+        '''
+    },
+    {
+        'id': 'SERVER_VNF_SAME_HOST',
+        'description': '''
+        Server instance and vnfs are are on the same
+        compute host. Server instance is on a different host
+        '''
+    },
+    {
+        'id': 'CLIENT_SERVER_SAME_HOST_SPLIT_VNF',
+        'description': '''
+        Client and server are on the same host.
+        The VNFs are split between hosts Round Robin.
+        '''
+    },
+    {
+        'id': 'CLIENT_SERVER_DIFFERENT_HOST_SPLIT_VNF',
+        'description': '''
+        Client and server are on different hosts.
+        The VNFs are split between hosts Round Robin.
+        '''
+    }
+]
+
+DEFAULT_TOPO = {
+    'id': 'DEFAULT',
+    'description': '''
+    The default topology created by nova scheduler
+    '''
+}
+
+
+def _get_seed():
+    '''
+    Get a seed based on the day of the week to choose which topology to test
+
+    NOTE: There's sure a smarter way to do this
+          Probably with the Jenkins job id
+    '''
+    cutoff = len(TOPOLOGIES - 1)
+    seed = datetime.datetime.today().weekday()
+    if seed > cutoff:
+        seed = random.randrange(cutoff)
+    return seed
+
+
+def _split_host_aggregates():
+    '''
+    Gets all the compute hosts and creates an aggregate for each.
+    Aggregates are named based on the convention compute1, compute2, ...
+    '''
+    nova_client = os_utils.get_nova_client()
+    hosts = os_utils.get_hypervisors(nova_client)
+    aggregates = []
+    for idx, host in enumerate(hosts):
+        az_name = 'compute{0}'.format(idx)
+        # aggregate name is the same as availability zone name
+        os_utils.create_aggregate_with_host(
+            nova_client, az_name, az_name, host)
+        aggregates.append(az_name)
+    # aggregates and av zones abstractions are tightly coupled in nova
+    return aggregates
+
+
+def clean_host_aggregates(aggregates):
+    '''
+    Clean all the created host aggregates
+    '''
+    nova_client = os_utils.get_nova_client()
+    for aggregate in aggregates:
+        if not os_utils.delete_aggregate(nova_client, aggregate):
+            logger.error('Could not delete aggregate {0}'
+                         .format(aggregate))
+
+
+def topology(vnf_names, host_aggregates=None, seed=None):
+    '''
+    Get the topology for client, server and vnfs.
+    The topology is returned as a dict in the form
+    {
+    'client': <availability_zone>,
+    'server': <availability_zone>,
+    'vnf1':   <availability_zone>,
+    'vnf2':   <availability_zone>
+    ...
+    }
+    Use seed=-1 to get the default topology created by nova-scheduler
+    '''
+
+    if host_aggregates is None:
+        host_aggregates = _split_host_aggregates()
+    if len(host_aggregates) < 2 or seed is None:
+        return None
+
+    topology = TOPOLOGIES[seed]
+    topology_assigment = {}
+    if topology['id'] == 'CLIENT_VNF_SAME_HOST':
+        topology_assigment['client'] = host_aggregates[0]
+        topology_assigment['server'] = host_aggregates[1]
+        for vnf in vnf_names:
+            topology_assigment[vnf] = host_aggregates[0]
+    elif topology['id'] == 'CLIENT_SERVER_SAME_HOST':
+        topology_assigment['client'] = host_aggregates[0]
+        topology_assigment['server'] = host_aggregates[0]
+        for vnf in vnf_names:
+            topology_assigment[vnf] = host_aggregates[1]
+    elif topology['id'] == 'SERVER_VNF_SAME_HOST':
+        topology_assigment['client'] = host_aggregates[1]
+        topology_assigment['server'] = host_aggregates[0]
+        for vnf in vnf_names:
+            topology_assigment[vnf] = host_aggregates[0]
+    elif topology['id'] == 'CLIENT_SERVER_SAME_HOST_SPLIT_VNF':
+        topology_assigment['client'] = host_aggregates[0]
+        topology_assigment['server'] = host_aggregates[0]
+        idx = 0
+        for vnf in vnf_names:
+            topology_assigment[vnf] = host_aggregates[idx % 2]
+            idx += 1
+    elif topology['id'] == 'CLIENT_SERVER_DIFFERENT_HOST_SPLIT_VNF':
+        topology_assigment['client'] = host_aggregates[0]
+        topology_assigment['server'] = host_aggregates[1]
+        idx = 0
+        for vnf in vnf_names:
+            topology_assigment[vnf] = host_aggregates[idx % 2]
+            idx += 1
+    logger.info("Creating enpoint and VNF topology on the compute hosts")
+    logger.info(topology['description'])
+    return topology_assigment