Fix metastatic missing pool config

The metastatic driver was ignoring the 3 standard pool configuration
options (max-servers, priority, and node-attributes) due to a missing
superclass method call.  Correct that and update tests to validate.

Further, the node-attributes option was undocumented for the metastatic
driver, so add it to the docs.

Change-Id: I6a65ea5b8ddb319bc131f87e0793f3626379e15f
Co-Authored-By: Benedikt Loeffler <benedikt.loeffler@bmw.de>

doc/source/metastatic.rst

@@ -85,6 +85,12 @@ itself, which is "meta".
           to apply to all pools within that provider, or it can be
           overridden here for a specific pool.
 
+       .. attr:: node-attributes
+          :type: dict
+
+          A dictionary of key-value pairs that will be stored with the node data
+          in ZooKeeper. The keys and values can be any arbitrary string.
+
        .. attr:: max-servers
           :type: int
 

nodepool/driver/metastatic/config.py

@@ -79,6 +79,7 @@ class MetastaticPool(ConfigPool):
         self.load(pool_config)
 
     def load(self, pool_config):
+        super().load(pool_config)
         self.name = pool_config['name']
         self.max_servers = pool_config.get('max-servers', math.inf)
         for label in pool_config.get('labels', []):

nodepool/tests/fixtures/metastatic.yaml

@@ -34,6 +34,9 @@ providers:
     pools:
       - name: main
         max-servers: 96
+        node-attributes:
+          backattr: back
+          testattr: backing
         labels:
           - name: backing-label
             cloud-image: fake-image
@@ -45,6 +48,10 @@ providers:
     pools:
       - name: main
         max-servers: 10
+        priority: 1
+        node-attributes:
+          metaattr: meta
+          testattr: metastatic
         labels:
           - name: user-label
             backing-label: backing-label

nodepool/tests/unit/test_driver_metastatic.py

@@ -85,6 +85,12 @@ class TestDriverMetastatic(tests.DBTestCase):
         pool = self.useNodepool(configfile, watermark_sleep=1)
         self.startPool(pool)
         manager = pool.getProviderManager('fake-provider')
+
+        pool_worker = pool.getPoolWorkers('meta-provider')[0]
+        pool_config = pool_worker.getPoolConfig()
+        self.assertEqual(pool_config.max_servers, 10)
+        self.assertEqual(pool_config.priority, 1)
+
         manager.adapter._client.create_image(name="fake-image")
 
         # Request a node, verify that there is a backing node, and it
@@ -104,6 +110,14 @@ class TestDriverMetastatic(tests.DBTestCase):
         self.assertEqual(bn1.host_keys, node1.host_keys)
         self.assertEqual(['ssh-rsa FAKEKEY'], node1.host_keys)
         self.assertEqual(bn1.id, node1.driver_data['backing_node'])
+        self.assertEqual(bn1.attributes, {
+            'backattr': 'back',
+            'testattr': 'backing',
+        })
+        self.assertEqual(node1.attributes, {
+            'metaattr': 'meta',
+            'testattr': 'metastatic',
+        })
 
         # Allocate a second node, should have same backing node
         node2 = self._requestNode()