raise exception if vm doesnt have any networks

onedns/api.py

@@ -1,3 +1,4 @@
+from onedns import exception
 from onedns.clients import one
 from onedns.clients import skydns
 from onedns.logger import log
@@ -13,10 +14,12 @@ class OneDNS(object):
         self._one = one.OneClient(**one_kwargs)
         self._skydns = skydns.SkyDNSClient(domain, etcd_kwargs=etcd_kwargs)
 
+    def _check_for_networks(self, vm):
+        if not hasattr(vm.template, 'nics'):
+            raise exception.NoNetworksError(vm)
+
     def _get_vm_dns_entries(self, vm):
         entries = {}
-        if not hasattr(vm.template, 'nics'):
-            return entries
         hostname = vm.name
         primary_ip = vm.template.nics[0].ip
         entries[hostname] = primary_ip
@@ -27,21 +30,15 @@ class OneDNS(object):
         return entries
 
     def add_vm(self, vm):
+        self._check_for_networks(vm)
         dns_entries = self._get_vm_dns_entries(vm)
-        if not dns_entries:
-            log.warn("No networks found for VM {id}: {vm} - skipping".format(
-                vm=vm.name, id=vm.id))
-            return
         log.info("Adding VM {id}: {vm}".format(id=vm.id, vm=vm.name))
         for name, ip in dns_entries.items():
             self._skydns.add_host(name, ip)
 
     def remove_vm(self, vm):
+        self._check_for_networks(vm)
         dns_entries = self._get_vm_dns_entries(vm)
-        if not dns_entries:
-            log.warn("No networks found for VM {id}: {vm} - skipping".format(
-                vm=vm.name, id=vm.id))
-            return
         log.info("Removing VM {id}: {vm}".format(id=vm.id, vm=vm.name))
         for name, ip in dns_entries.items():
             self._skydns.remove_host(name, ip)
@@ -56,4 +53,7 @@ class OneDNS(object):
 
     def sync(self):
         for vm in self._one.vms():
-            self.add_vm(vm)
+            try:
+                self.add_vm(vm)
+            except exception.NoNetworksError as e:
+                e.log(warn=True)

onedns/exception.py

@@ -0,0 +1,30 @@
+from onedns.logger import log
+
+
+class OneDnsException(Exception):
+    def __init__(self, *args):
+        self.args = args
+        self.msg = args[0]
+
+    def __str__(self):
+        return self.msg
+
+    def explain(self):
+        return '%s: %s' % (self.__class__.__name__, self.msg)
+
+    def log(self, warn=False, show_tb=False):
+        if show_tb:
+            log.exception(self.explain())
+        elif warn:
+            log.warn(self.explain())
+        else:
+            log.error(self.explain())
+
+
+class NoNetworksError(OneDnsException):
+    """
+    Raised when a VM doesn't have any NICs
+    """
+    def __init__(self, vm):
+        self.msg = "No networks found for VM {id}: {vm}".format(vm=vm.name,
+                                                                id=vm.id)