CORD-2965 Kubernetes Synchronizer

Change-Id: Ie5c02b9ad1c65af686598bab0b36350ac1caef64
diff --git a/xos/synchronizer/steps/sync_service.py b/xos/synchronizer/steps/sync_service.py
new file mode 100644
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+++ b/xos/synchronizer/steps/sync_service.py
@@ -0,0 +1,130 @@
+
+# Copyright 2017-present Open Networking Foundation
+#
+# 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.
+
+"""
+    sync_service.py
+
+    Synchronize Services. The only type of Service this step knows how to deal with are services that use Kubernetes
+    NodePort to expose ports.
+"""
+
+from synchronizers.new_base.syncstep import SyncStep
+from synchronizers.new_base.modelaccessor import Service
+
+from xosconfig import Config
+from multistructlog import create_logger
+
+from kubernetes.client.rest import ApiException
+from kubernetes import client as kubernetes_client, config as kubernetes_config
+
+log = create_logger(Config().get('logging'))
+
+class SyncService(SyncStep):
+
+    """
+        SyncService
+
+        Implements sync step for syncing Services.
+    """
+
+    provides = [Service]
+    observes = Service
+    requested_interval = 0
+
+    def __init__(self, *args, **kwargs):
+        super(SyncService, self).__init__(*args, **kwargs)
+        kubernetes_config.load_incluster_config()
+        self.v1 = kubernetes_client.CoreV1Api()
+
+    def fetch_pending(self, deletion=False):
+        """ Filter the set of pending objects.
+            As this syncstep can only create Service that exist within Trust Domains, filter out those services that
+            don't have Trust Domains associated with them.
+        """
+        models = super(SyncService, self).fetch_pending(deletion)
+
+        if (not deletion):
+            for model in models[:]:
+                if not self.get_trust_domain(model):
+                    log.info("Unable to determine Trust Domain for service %s. Ignoring." % model.name)
+                    models.remove(model)
+                elif not model.serviceports.exists():
+                    # If there are not ServicePorts, then there's not much for us to do at this time...
+                    log.info("Service %s is not interesting. Ignoring." % model.name)
+                    models.remove(model)
+
+        return models
+
+    def get_trust_domain(self, o):
+        """ Given a service, determine its Trust Domain.
+
+            The design we've chosen to go with is that a service is pinned to a Trust Domain based on the slices
+            that it contains. It's an error for a service to be directly comprised of slices from multiple
+            trust domains.
+
+            This allows for "logical services", that contain no slices of their own, but are comprised of multiple
+            subservices. For example, EPC.
+        """
+
+        trust_domain = None
+        for slice in o.slices.all():
+            if slice.trust_domain:
+                if (trust_domain is None):
+                    trust_domain = slice.trust_domain
+                elif (trust_domain.id != slice.trust_domain.id):
+                    # Bail out of we've encountered a situation where a service spans multiple trust domains.
+                    log.warning("Service %s is comprised of slices from multiple trust domains." % o.name)
+                    return None
+
+        return trust_domain
+
+    def get_service(self, o, trust_domain):
+        """ Given an XOS Service, read the associated Service from Kubernetes.
+            If no Kubernetes service exists, return None
+        """
+        try:
+            k8s_service = self.v1.read_namespaced_service(o.name, trust_domain.name)
+        except ApiException, e:
+            if e.status == 404:
+                return None
+            raise
+        return k8s_service
+
+    def sync_record(self, o):
+        trust_domain = self.get_trust_domain(o)
+        k8s_service = self.get_service(o,trust_domain)
+
+        if not k8s_service:
+            k8s_service = kubernetes_client.V1Service()
+            k8s_service.metadata = kubernetes_client.V1ObjectMeta(name=o.name)
+
+            ports=[]
+            for service_port in o.serviceports.all():
+                port=kubernetes_client.V1ServicePort(name = service_port.name,
+                                                  node_port = service_port.external_port,
+                                                  port = service_port.internal_port,
+                                                  target_port = service_port.internal_port,
+                                                  protocol = service_port.protocol)
+                ports.append(port)
+
+            k8s_service.spec = kubernetes_client.V1ServiceSpec(ports=ports,
+                                                               type="NodePort")
+
+            self.v1.create_namespaced_service(trust_domain.name, k8s_service)
+
+    def delete_record(self, o):
+        # TODO(smbaker): Implement delete step
+        pass
+