Ec2: only attempt to operate at local mode on known platforms.

This change makes the DataSourceEc2Local do nothing unless it is on
actual AWS platform. The motivation is twofold:

a.) It is generally safer to only make this function available to Ec2
clones that explicitly identify themselves to the guest. (It also
gives them a reason to supply identification code to cloud-init.)

b.) On non-intel OpenStack platforms ds-identify would enable both the Ec2
and OpenStack sources. That is because there is not good data (such as
dmi) to positively identify the platform. Previously that would be fine
as OpenStack would run first and be successful. The change to add Ec2Local
meant that an Ec2 now runs first.

The best case for 'b' would be a slow down as attempts at the Ec2 metadata
service time out. The discovered case was worse.

Additionally we add a simple check for datatype of 'network' in the
metadata before attempting to read it.

LP: #1715128

1 files changed, 25 insertions, 4 deletions

diff --git a/tests/unittests/test_datasource/test_ec2.py b/tests/unittests/test_datasource/test_ec2.py
index 9fb90483..a7301dbf 100644
--- a/tests/unittests/test_datasource/test_ec2.py
+++ b/tests/unittests/test_datasource/test_ec2.py
@@ -279,6 +279,27 @@ class TestEc2(test_helpers.HttprettyTestCase):
         ret = ds.get_data()
         self.assertTrue(ret)
 
+    def test_ec2_local_returns_false_on_non_aws(self):
+        """DataSourceEc2Local returns False when platform is not AWS."""
+        self.datasource = ec2.DataSourceEc2Local
+        ds = self._setup_ds(
+            platform_data=self.valid_platform_data,
+            sys_cfg={'datasource': {'Ec2': {'strict_id': False}}},
+            md=DEFAULT_METADATA)
+        platform_attrs = [
+            attr for attr in ec2.Platforms.__dict__.keys()
+            if not attr.startswith('__')]
+        for attr_name in platform_attrs:
+            platform_name = getattr(ec2.Platforms, attr_name)
+            if platform_name != 'AWS':
+                ds._cloud_platform = platform_name
+                ret = ds.get_data()
+                self.assertFalse(ret)
+                message = (
+                    "Local Ec2 mode only supported on ('AWS',),"
+                    ' not {0}'.format(platform_name))
+                self.assertIn(message, self.logs.getvalue())
+
     @httpretty.activate
     @mock.patch('cloudinit.sources.DataSourceEc2.util.is_FreeBSD')
     def test_ec2_local_returns_false_on_bsd(self, m_is_freebsd):
@@ -336,8 +357,8 @@ class TestConvertEc2MetadataNetworkConfig(test_helpers.CiTestCase):
         super(TestConvertEc2MetadataNetworkConfig, self).setUp()
         self.mac1 = '06:17:04:d7:26:09'
         self.network_metadata = {
-            'network': {'interfaces': {'macs': {
-                self.mac1: {'public-ipv4s': '172.31.2.16'}}}}}
+            'interfaces': {'macs': {
+                self.mac1: {'public-ipv4s': '172.31.2.16'}}}}
 
     def test_convert_ec2_metadata_network_config_skips_absent_macs(self):
         """Any mac absent from metadata is skipped by network config."""
@@ -357,7 +378,7 @@ class TestConvertEc2MetadataNetworkConfig(test_helpers.CiTestCase):
         macs_to_nics = {self.mac1: 'eth9'}
         network_metadata_ipv6 = copy.deepcopy(self.network_metadata)
         nic1_metadata = (
-            network_metadata_ipv6['network']['interfaces']['macs'][self.mac1])
+            network_metadata_ipv6['interfaces']['macs'][self.mac1])
         nic1_metadata['ipv6s'] = '2620:0:1009:fd00:e442:c88d:c04d:dc85/64'
         nic1_metadata.pop('public-ipv4s')
         expected = {'version': 1, 'config': [
@@ -373,7 +394,7 @@ class TestConvertEc2MetadataNetworkConfig(test_helpers.CiTestCase):
         macs_to_nics = {self.mac1: 'eth9'}
         network_metadata_both = copy.deepcopy(self.network_metadata)
         nic1_metadata = (
-            network_metadata_both['network']['interfaces']['macs'][self.mac1])
+            network_metadata_both['interfaces']['macs'][self.mac1])
         nic1_metadata['ipv6s'] = '2620:0:1009:fd00:e442:c88d:c04d:dc85/64'
         expected = {'version': 1, 'config': [
             {'mac_address': self.mac1, 'type': 'physical',