[CORD-2516] Implement HSS-DB service and its synchronizer

Change-Id: I3b5185669bf8a4506d4d60b8bc858537f41c640a
diff --git a/xos/hssdb.xproto b/xos/hssdb.xproto
new file mode 100644
index 0000000..f6a4429
--- /dev/null
+++ b/xos/hssdb.xproto
@@ -0,0 +1,18 @@
+option name = "hssdb";
+option app_label = "hssdb";
+
+message HSSDBService (Service){
+    option verbose_name = "HSS Database Service";
+}
+
+message HSSDBVendor (XOSBase){
+    option verbose_name = "HSS Database Vendor";
+    required string name = 1 [help_text = "vendor name", max_length = 32, null = False, db_index = False, blank = False];
+    required manytoone image->Image:+ = 2 [help_text = "select image for this vendor", db_index = True, null = False, blank = False];
+    required manytoone flavor->Flavor:+ = 3 [help_text = "select openstack flavor for vendor image", db_index = True, null = False, blank = False];
+}
+
+message HSSDBServiceInstance (TenantWithContainer){
+    option verbose_name = "HSS Database ServiceInstance";
+    optional manytoone hssdb_vendor->HSSDBVendor:vendor_tenants = 1 [help_text = "select vendor of choice, leave blank for slice default", db_index = True, null = True, blank = True];
+}
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