support network configuration in cloud-init --local

this allows 'cloud-init --local' to fully run before networking comes up.
By doing so, we can now cleanly apply networking to the new system.

This adds support for reading ConfigDrive network configuration
and also from NoCloud.  The support is only present for ubuntu/debian
at the current time.  Other distros will follow.

Also ability to specify network configuration on kernel command line
via either ip= or network-config=<base64>.

2 files changed, 22 insertions, 1 deletions

diff --git a/cloudinit/distros/__init__.py b/cloudinit/distros/__init__.py
index e8220985..418421b9 100644
--- a/cloudinit/distros/__init__.py
+++ b/cloudinit/distros/__init__.py
@@ -75,6 +75,9 @@ class Distro(object):
         # to write this blob out in a distro format
         raise NotImplementedError()
 
+    def _write_network_config(self, settings):
+        raise NotImplementedError()
+
     def _find_tz_file(self, tz):
         tz_file = os.path.join(self.tz_zone_dir, str(tz))
         if not os.path.isfile(tz_file):
@@ -132,6 +135,14 @@ class Distro(object):
             return self._bring_up_interfaces(dev_names)
         return False
 
+    def apply_network_config(self, netconfig, bring_up=False):
+        # Write it out
+        dev_names = self._write_network_config(netconfig)
+        # Now try to bring them up
+        if bring_up:
+            return self._bring_up_interfaces(dev_names)
+        return False
+
     @abc.abstractmethod
     def apply_locale(self, locale, out_fn=None):
         raise NotImplementedError()
diff --git a/cloudinit/distros/debian.py b/cloudinit/distros/debian.py
index db5890b1..b14fa3e2 100644
--- a/cloudinit/distros/debian.py
+++ b/cloudinit/distros/debian.py
@@ -26,6 +26,7 @@ from cloudinit import distros
 from cloudinit import helpers
 from cloudinit import log as logging
 from cloudinit import util
+from cloudinit import net
 
 from cloudinit.distros.parsers.hostname import HostnameConf
 
@@ -45,7 +46,8 @@ APT_GET_WRAPPER = {
 class Distro(distros.Distro):
     hostname_conf_fn = "/etc/hostname"
     locale_conf_fn = "/etc/default/locale"
-    network_conf_fn = "/etc/network/interfaces"
+    network_conf_fn = "/etc/network/interfaces.d/50-cloud-init.cfg"
+    links_prefix = "/etc/systemd/network/50-cloud-init-"
 
     def __init__(self, name, cfg, paths):
         distros.Distro.__init__(self, name, cfg, paths)
@@ -76,6 +78,14 @@ class Distro(distros.Distro):
         util.write_file(self.network_conf_fn, settings)
         return ['all']
 
+    def _write_network_config(self, netconfig):
+        ns = net.parse_net_config_data(netconfig)
+        net.render_network_state(target="/", network_state=ns,
+                                 eni=self.network_conf_fn,
+                                 links_prefix=self.links_prefix)
+        util.del_file("/etc/network/interfaces.d/eth0.cfg")
+        return []
+
     def _bring_up_interfaces(self, device_names):
         use_all = False
         for d in device_names: