Merge "Add metadata interface for instance data"

cloudbaseinit/metadata/services/base.py

@@ -14,6 +14,7 @@
 
 
 import abc
+import copy
 import gzip
 import io
 import time
@@ -221,6 +222,45 @@ class BaseMetadataService(object):
     def get_ephemeral_disk_data_loss_warning(self):
         raise NotExistingMetadataException()
 
+    def get_instance_data(self):
+        """Returns a dictionary with instance data from the metadata source
+
+        The instance data structure is based on the cloud-init specifications:
+        https://cloudinit.readthedocs.io/en/latest/topics/instancedata.html
+
+        The v1 namespace contains a subset of the cloud-init standard
+        for the instance data. In the future, it should reach parity with the
+        cloud-init standard.
+
+        The ds.meta_data namespace contains all the values the v1 namespace
+        contains, in order to be compatible with cloud-init, plus a subset of
+        other instance data.
+        The ds namespace can change without prior notice and should not be
+        used in production.
+        """
+
+        instance_id = self.get_instance_id()
+        hostname = self.get_host_name()
+
+        v1_data = {
+            "instance_id": instance_id,
+            "local_hostname": hostname,
+            "public_ssh_keys": self.get_public_keys()
+        }
+
+        # Copy the v1 data to the ds.meta_data and add more fields
+        ds_meta_data = copy.deepcopy(v1_data)
+        ds_meta_data.update({
+            "hostname": hostname
+        })
+
+        return {
+            "v1": v1_data,
+            "ds": {
+                "meta_data": ds_meta_data,
+            }
+        }
+
 
 class BaseHTTPMetadataService(BaseMetadataService):
 

cloudbaseinit/tests/metadata/services/test_base.py

@@ -61,6 +61,38 @@ class TestBase(unittest.TestCase):
         result = self._service.get_user_pwd_encryption_key()
         self.assertEqual(result, mock_get_public_keys.return_value[0])
 
+    @mock.patch('cloudbaseinit.metadata.services.base.'
+                'BaseMetadataService.get_public_keys')
+    @mock.patch('cloudbaseinit.metadata.services.base.'
+                'BaseMetadataService.get_host_name')
+    @mock.patch('cloudbaseinit.metadata.services.base.'
+                'BaseMetadataService.get_instance_id')
+    def test_get_instance_data(self, mock_instance_id, mock_hostname,
+                               mock_public_keys):
+        fake_instance_id = 'id'
+        mock_instance_id.return_value = fake_instance_id
+        fake_hostname = 'host'
+        mock_hostname.return_value = fake_hostname
+        fake_keys = ['ssh1', 'ssh2']
+        mock_public_keys.return_value = fake_keys
+
+        expected_response = {
+            'v1': {
+                "instance_id": fake_instance_id,
+                "local_hostname": fake_hostname,
+                "public_ssh_keys": fake_keys
+            },
+            'ds': {
+                'meta_data': {
+                    "instance_id": fake_instance_id,
+                    "local_hostname": fake_hostname,
+                    "public_ssh_keys": fake_keys,
+                    "hostname": fake_hostname
+                },
+            }
+        }
+        self.assertEqual(expected_response, self._service.get_instance_data())
+
 
 class TestBaseHTTPMetadataService(unittest.TestCase):