Add support for network labels

This patch adds the ability to specify a net-label
instead of using a net-id (network UUID).

Rather than use network UUID's in our nodepool.yaml
config files it would be nice to use the more meaningful
network labels instead. This should make the config file
more readable across the various cloud providers and
matches how we use image names (instead of image
UUIDs) as well.

The current implementation relies on the os-tenant-networks
extension in Nova to provide the network label lookup.
Given that nodepool is currently focused around using
novaclient this made the most sense. We may at some point
in the future want to use the Neutron API directly for
this information or perhaps use a combination of both
approaches to accommodate a variety of provider API
deployment choices.

Tested locally on my TripleO overcloud using two
Neutron networks.

Change-Id: I9bdd35adf2d85659cf1b992ccd2fcf98fb124528

doc/source/configuration.rst

@@ -153,6 +153,9 @@ same name.  Example::
       boot-timeout: 120
       launch-timeout: 900
       template-hostname: '{image.name}-{timestamp}.template.openstack.org'
+      networks:
+        - net-id: 'some-uuid'
+        - net-label: 'some-network-name'
       images:
         - name: precise
           base-image: 'Precise'
@@ -199,6 +202,13 @@ Both `boot-timeout` and `launch-timeout` keys are optional.  The
 `boot-timeout` key defaults to 60 seconds and `launch-timeout` key
 will default to 3600 seconds.
 
+The optional `networks` section may be used to specify custom
+Neutron networks that get attached to each node. You can specify
+Neutron networks using either the `net-id` or `net-label`. If
+only the `net-label` is specified the network UUID is automatically
+queried via the Nova os-tenant-networks API extension (this requires
+that the cloud provider has deployed this extension).
+
 The `availability-zones` key is optional. Without it nodepool will rely
 on nova to schedule an availability zone. If it is provided the value
 should be a list of availability zone names. Nodepool will select one

nodepool/nodepool.py

@@ -1014,7 +1014,7 @@ class NodePool(threading.Thread):
             p.boot_timeout = provider.get('boot-timeout', 60)
             p.launch_timeout = provider.get('launch-timeout', 3600)
             p.use_neutron = bool(provider.get('networks', ()))
-            p.nics = provider.get('networks')
+            p.networks = provider.get('networks')
             p.azs = provider.get('availability-zones')
             p.template_hostname = provider.get(
                 'template-hostname',
@@ -1084,7 +1084,7 @@ class NodePool(threading.Thread):
             new_pm.boot_timeout != old_pm.provider.boot_timeout or
             new_pm.launch_timeout != old_pm.provider.launch_timeout or
             new_pm.use_neutron != old_pm.provider.use_neutron or
-            new_pm.nics != old_pm.provider.nics or
+            new_pm.networks != old_pm.provider.networks or
             new_pm.azs != old_pm.provider.azs):
             return False
         new_images = new_pm.images

nodepool/provider_manager.py

@@ -20,6 +20,8 @@ import logging
 import paramiko
 import novaclient
 import novaclient.client
+import novaclient.extension
+import novaclient.v1_1.contrib.tenant_networks
 import threading
 import time
 
@@ -219,6 +221,12 @@ class DeleteImageTask(Task):
         client.images.delete(**self.args)
 
 
+class FindNetworkTask(Task):
+    def main(self, client):
+        network = client.tenant_networks.find(**self.args)
+        return dict(id=str(network.id))
+
+
 class ProviderManager(TaskManager):
     log = logging.getLogger("nodepool.ProviderManager")
 
@@ -228,6 +236,7 @@ class ProviderManager(TaskManager):
         self.provider = provider
         self._client = self._getClient()
         self._images = {}
+        self._networks = {}
         self._cloud_metadata_read = False
         self.__flavors = {}
         self.__extensions = {}
@@ -253,9 +262,11 @@ class ProviderManager(TaskManager):
         self._cloud_metadata_read = True
 
     def _getClient(self):
+        tenant_networks = novaclient.extension.Extension(
+            'tenant_networks', novaclient.v1_1.contrib.tenant_networks)
         args = ['1.1', self.provider.username, self.provider.password,
                 self.provider.project_id, self.provider.auth_url]
-        kwargs = {}
+        kwargs = {'extensions': [tenant_networks]}
         if self.provider.service_type:
             kwargs['service_type'] = self.provider.service_type
         if self.provider.service_name:
@@ -295,6 +306,13 @@ class ProviderManager(TaskManager):
         self._images[name] = image
         return image
 
+    def findNetwork(self, label):
+        if label in self._networks:
+            return self._networks[label]
+        network = self.submitTask(FindNetworkTask(label=label))
+        self._networks[label] = network
+        return network
+
     def deleteImage(self, name):
         if name in self._images:
             del self._images[name]
@@ -323,7 +341,16 @@ class ProviderManager(TaskManager):
         if az:
             create_args['availability_zone'] = az
         if self.provider.use_neutron:
-            create_args['nics'] = self.provider.nics
+            nics = []
+            for network in self.provider.networks:
+                if 'net-id' in network:
+                    nics.append({'net-id': network['net-id']})
+                elif 'net-label' in network:
+                    net_id = self.findNetwork(network['net-label'])['id']
+                    nics.append({'net-id': net_id})
+                else:
+                    raise Exception("Invalid 'networks' configuration.")
+            create_args['nics'] = nics
 
         return self.submitTask(CreateServerTask(**create_args))
 

tools/fake.yaml

@@ -37,6 +37,7 @@ providers:
     pool: 'fake'
     networks:
       - net-id: 'some-uuid'
+      - net-label: 'some-label'
     images:
       - name: nodepool-fake
         base-image: 'Fake Precise'