cloudinit.net: add network config v2 parsing and rendering

Network configuration version 2 format is implemented in a package
called netplan (nplan)[1] which allows consolidated network config
for multiple network controllers.

- Add a new netplan renderer
- Update default policy, placing eni and sysconfig first
  This requires explicit policy to enable netplan over eni
  on systems which have both (Yakkety, Zesty, UC16)
- Allow any network state (parsed from any format cloud-init supports) to
  render to v2 if system supports netplan.
- Move eni's _subnet_is_ipv6 to common code for use by other renderers
- Make sysconfig renderer always emit /etc/syconfig/network configuration
- Update cloud-init.service systemd unit to also wait on
  systemd-networkd-wait-online.service

1. https://lists.ubuntu.com/archives/ubuntu-devel/2016-July/039464.html

1 files changed, 3 insertions, 12 deletions

diff --git a/cloudinit/net/eni.py b/cloudinit/net/eni.py
index f471e05f..9819d4f5 100644
--- a/cloudinit/net/eni.py
+++ b/cloudinit/net/eni.py
@@ -8,6 +8,7 @@ import re
 from . import ParserError
 
 from . import renderer
+from .network_state import subnet_is_ipv6
 
 from cloudinit import util
 
@@ -111,16 +112,6 @@ def _iface_start_entry(iface, index, render_hwaddress=False):
     return lines
 
 
-def _subnet_is_ipv6(subnet):
-    # 'static6' or 'dhcp6'
-    if subnet['type'].endswith('6'):
-        # This is a request for DHCPv6.
-        return True
-    elif subnet['type'] == 'static' and ":" in subnet['address']:
-        return True
-    return False
-
-
 def _parse_deb_config_data(ifaces, contents, src_dir, src_path):
     """Parses the file contents, placing result into ifaces.
 
@@ -370,7 +361,7 @@ class Renderer(renderer.Renderer):
                 iface['mode'] = subnet['type']
                 iface['control'] = subnet.get('control', 'auto')
                 subnet_inet = 'inet'
-                if _subnet_is_ipv6(subnet):
+                if subnet_is_ipv6(subnet):
                     subnet_inet += '6'
                 iface['inet'] = subnet_inet
                 if subnet['type'].startswith('dhcp'):
@@ -486,7 +477,7 @@ class Renderer(renderer.Renderer):
 def network_state_to_eni(network_state, header=None, render_hwaddress=False):
     # render the provided network state, return a string of equivalent eni
     eni_path = 'etc/network/interfaces'
-    renderer = Renderer({
+    renderer = Renderer(config={
         'eni_path': eni_path,
         'eni_header': header,
         'links_path_prefix': None,