openstack provider: ignore ec2 metadata if not present

Signed-off-by: Riccardo Piccoli <rpiccoli@redhat.com>

Author: rccrdpccl

src/providers/openstack/configdrive.rs

@@ -144,17 +144,21 @@ impl OpenstackConfigDrive {
 impl MetadataProvider for OpenstackConfigDrive {
     fn attributes(&self) -> Result<HashMap<String, String>> {
         let mut out = HashMap::with_capacity(6);
-        let metadata_ec2: MetadataEc2JSON = self.read_metadata_ec2()?;
         let metadata_openstack: MetadataOpenstackJSON = self.read_metadata_openstack()?;
         if let Some(hostname) = metadata_openstack.hostname {
             out.insert("OPENSTACK_HOSTNAME".to_string(), hostname);
         }
-        if let Some(instance_id) = metadata_ec2.instance_id {
-            out.insert("OPENSTACK_INSTANCE_ID".to_string(), instance_id);
-        }
         if let Some(uuid) = metadata_openstack.uuid {
             out.insert("OPENSTACK_INSTANCE_UUID".to_string(), uuid);
         }
+
+        let metadata_ec2 = match self.read_metadata_ec2() {
+            Ok(metadata) => metadata,
+            Err(error) => return Ok(out),
+        };
+        if let Some(instance_id) = metadata_ec2.instance_id {
+            out.insert("OPENSTACK_INSTANCE_ID".to_string(), instance_id);
+        }
         if let Some(instance_type) = metadata_ec2.instance_type {
             out.insert("OPENSTACK_INSTANCE_TYPE".to_string(), instance_type);
         }