Add some metadata logging to root cause ssh failure

Instances aren't getting SSH keys in some circumstances.
This adds a few debug statements to see if the Nova metadata
service thinks an instance has keys.

Related-Bug: #1668958
Change-Id: I3095d3024b62d5ebb4ea9e388a40ed94ef8f832b

nova/api/metadata/base.py

@@ -310,6 +310,11 @@ class InstanceMetadata(object):
         if self.userdata_raw is not None:
             data['user-data'] = self.userdata_raw
 
+        # TODO(kevinbenton): remove after bug/1668958 is resolved
+        LOG.debug("Instance %s metadata: %s",
+                  self.instance.ec2_ids.instance_id, data,
+                  instance=self.instance)
+
         return data
 
     def get_ec2_item(self, path_tokens):

nova/api/metadata/handler.py

@@ -125,6 +125,8 @@ class MetadataRequestHandler(wsgi.Application):
         resp = base.ec2_md_print(data)
         req.response.body = encodeutils.to_utf8(resp)
 
+        # TODO(kevinbenton): remove after bug/1668958 is resolved
+        LOG.debug("Metadata response body %s", req.response.body)
         req.response.content_type = meta_data.get_mimetype()
         return req.response