epc-as-a-service functionality added

Change-Id: I85e9c725575df0044236e20b7900008755029ab2
diff --git a/xos/models.py b/xos/models.py
index 56350a7..f8d4c16 100644
--- a/xos/models.py
+++ b/xos/models.py
@@ -15,13 +15,16 @@
 import traceback
 from xos.exceptions import *
 from xos.config import Config
-from django.contrib.contenttypes.models import ContentType
-from django.contrib.contenttypes.fields import GenericForeignKey
 
 class VSMService(VSMService_decl):
    class Meta:
         proxy = True 
 
+   def create_tenant(self, **kwargs):
+       t = VSMTenant(kind="vEPC", provider_service=self, connect_method="na", **kwargs)
+       t.save()
+       return t
+
 class VSMTenant(VSMTenant_decl):
    class Meta:
         proxy = True 
@@ -34,6 +37,13 @@
        super(VSMTenant, self).__init__(*args, **kwargs)
 
    def save(self, *args, **kwargs):
+       if not self.creator:
+           if not getattr(self, "caller", None):
+               raise XOSProgrammingError("VSMTenant's self.caller was not set")
+           self.creator = self.caller
+           if not self.creator:
+               raise XOSProgrammingError("VSMTenant's self.creator was not set")
+
        super(VSMTenant, self).save(*args, **kwargs)
        # This call needs to happen so that an instance is created for this
        # tenant is created in the slice. One instance is created per tenant.
diff --git a/xos/tosca/custom_types/vsm.m4 b/xos/tosca/custom_types/vsm.m4
index 2c839a8..1613c4f 100644
--- a/xos/tosca/custom_types/vsm.m4
+++ b/xos/tosca/custom_types/vsm.m4
@@ -22,6 +22,3 @@
             VSM Tenant
         properties:
             xos_base_tenant_props
-            tenant_message:
-                type: string
-                required: false
diff --git a/xos/tosca/custom_types/vsm.yaml b/xos/tosca/custom_types/vsm.yaml
index a9603fb..ff8ef88 100644
--- a/xos/tosca/custom_types/vsm.yaml
+++ b/xos/tosca/custom_types/vsm.yaml
@@ -92,6 +92,3 @@
                 type: string
                 required: false
                 description: Service specific ID opaque to XOS but meaningful to service
-            tenant_message:
-                type: string
-                required: false
diff --git a/xos/tosca/resources/vsmtenant.py b/xos/tosca/resources/vsmtenant.py
index e932953..4e84561 100644
--- a/xos/tosca/resources/vsmtenant.py
+++ b/xos/tosca/resources/vsmtenant.py
@@ -4,7 +4,7 @@
 class XOSVSMTenant(XOSResource):
     provides = "tosca.nodes.VSMTenant"
     xos_model = VSMTenant
-    copyin_props = ("tenant_message",) 
+    copyin_props = () 
     name_field = None  
 
     def get_xos_args(self, throw_exception=True):
diff --git a/xos/vsm.xproto b/xos/vsm.xproto
index 9a9848c..3093dba 100644
--- a/xos/vsm.xproto
+++ b/xos/vsm.xproto
@@ -12,5 +12,4 @@
 message VSMTenant (TenantWithContainer){
      option name = "VSMTenant";
      option verbose_name = "Virtual Session Management Tenant";
-     required string tenant_message = 1 [help_text = "Tenant Message to Display", max_length = 254, null = False, db_index = False, blank = False];
 }