Azure: Add network-config, Refactor net layer to handle duplicate macs.

On systems with network devices with duplicate mac addresses, cloud-init
will fail to rename the devices according to the specified network
configuration. Refactor net layer to search by device driver and device
id if available. Azure systems may have duplicate mac addresses by
design.

Update Azure datasource to run at init-local time and let Azure datasource
generate a fallback networking config to handle advanced networking
configurations.

Lastly, add a 'setup' method to the datasources that is called before
userdata/vendordata is processed but after networking is up. That is
used here on Azure to interact with the 'fabric'.

1 files changed, 14 insertions, 1 deletions

diff --git a/cloudinit/sources/__init__.py b/cloudinit/sources/__init__.py
index c3ce36d6..952caf35 100644
--- a/cloudinit/sources/__init__.py
+++ b/cloudinit/sources/__init__.py
@@ -251,10 +251,23 @@ class DataSource(object):
     def first_instance_boot(self):
         return
 
+    def setup(self, is_new_instance):
+        """setup(is_new_instance)
+
+        This is called before user-data and vendor-data have been processed.
+
+        Unless the datasource has set mode to 'local', then networking
+        per 'fallback' or per 'network_config' will have been written and
+        brought up the OS at this point.
+        """
+        return
+
     def activate(self, cfg, is_new_instance):
         """activate(cfg, is_new_instance)
 
-        This is called before the init_modules will be called.
+        This is called before the init_modules will be called but after
+        the user-data and vendor-data have been fully processed.
+
         The cfg is fully up to date config, it contains a merged view of
            system config, datasource config, user config, vendor config.
         It should be used rather than the sys_cfg passed to __init__.