OpenNebula: Improve network configuration support.

Network configuration in OpenNebula would only work if the host correctly
guessed the names of the devices in the guest. OpenNebula provided data
in its context.sh like 'ETH0_NETWORK', but if the guest named devices
differently then results were not predictable. This would occur with
Predictable Network Interface Names. To address this,
newer versions (of OpenNebula provide the mac address ETH0_MAC.
This function is present in 4.14 and documented officially in 5.0 docs.

This provides support for reading the mac addresses from the context.sh.
It also fixes cases where context.sh provided a field (ETH0_NETWORK
or ETH0_MASK) with a empty string. Previously the empty string would
be used rather than falling back to the default.

LP: #1719157, #1716397, #1736750

2 files changed, 61 insertions, 55 deletions

diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
index a1b0db10..c015e793 100644
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -18,7 +18,7 @@ SYS_CLASS_NET = "/sys/class/net/"
 DEFAULT_PRIMARY_INTERFACE = 'eth0'
 
 
-def _natural_sort_key(s, _nsre=re.compile('([0-9]+)')):
+def natural_sort_key(s, _nsre=re.compile('([0-9]+)')):
     """Sorting for Humans: natural sort order. Can be use as the key to sort
     functions.
     This will sort ['eth0', 'ens3', 'ens10', 'ens12', 'ens8', 'ens0'] as
@@ -224,7 +224,7 @@ def find_fallback_nic(blacklist_drivers=None):
 
     # if eth0 exists use it above anything else, otherwise get the interface
     # that we can read 'first' (using the sorted defintion of first).
-    names = list(sorted(potential_interfaces, key=_natural_sort_key))
+    names = list(sorted(potential_interfaces, key=natural_sort_key))
     if DEFAULT_PRIMARY_INTERFACE in names:
         names.remove(DEFAULT_PRIMARY_INTERFACE)
         names.insert(0, DEFAULT_PRIMARY_INTERFACE)
diff --git a/cloudinit/sources/DataSourceOpenNebula.py b/cloudinit/sources/DataSourceOpenNebula.py
index f66c95d7..ce47b6bd 100644
--- a/cloudinit/sources/DataSourceOpenNebula.py
+++ b/cloudinit/sources/DataSourceOpenNebula.py
@@ -12,6 +12,7 @@
 #
 # This file is part of cloud-init. See LICENSE file for license information.
 
+import collections
 import os
 import pwd
 import re
@@ -19,6 +20,7 @@ import string
 
 from cloudinit import log as logging
 from cloudinit import net
+from cloudinit.net import eni
 from cloudinit import sources
 from cloudinit import util
 
@@ -89,11 +91,18 @@ class DataSourceOpenNebula(sources.DataSource):
             return False
 
         self.seed = seed
-        self.network_eni = results.get("network_config")
+        self.network_eni = results.get('network-interfaces')
         self.metadata = md
         self.userdata_raw = results.get('userdata')
         return True
 
+    @property
+    def network_config(self):
+        if self.network_eni is not None:
+            return eni.convert_eni_data(self.network_eni)
+        else:
+            return None
+
     def get_hostname(self, fqdn=False, resolve_ip=None):
         if resolve_ip is None:
             if self.dsmode == sources.DSMODE_NETWORK:
@@ -116,58 +125,53 @@ class OpenNebulaNetwork(object):
         self.context = context
         if system_nics_by_mac is None:
             system_nics_by_mac = get_physical_nics_by_mac()
-        self.ifaces = system_nics_by_mac
+        self.ifaces = collections.OrderedDict(
+            [k for k in sorted(system_nics_by_mac.items(),
+                               key=lambda k: net.natural_sort_key(k[1]))])
+
+        # OpenNebula 4.14+ provide macaddr for ETHX in variable ETH_MAC.
+        # context_devname provides {mac.lower():ETHX, mac2.lower():ETHX}
+        self.context_devname = {}
+        for k, v in context.items():
+            m = re.match(r'^(.+)_MAC$', k)
+            if m:
+                self.context_devname[v.lower()] = m.group(1)
 
     def mac2ip(self, mac):
-        components = mac.split(':')[2:]
-        return [str(int(c, 16)) for c in components]
+        return '.'.join([str(int(c, 16)) for c in mac.split(':')[2:]])
 
-    def get_ip(self, dev, components):
-        var_name = dev.upper() + '_IP'
-        if var_name in self.context:
-            return self.context[var_name]
-        else:
-            return '.'.join(components)
+    def mac2network(self, mac):
+        return self.mac2ip(mac).rpartition(".")[0] + ".0"
 
-    def get_mask(self, dev):
-        var_name = dev.upper() + '_MASK'
-        if var_name in self.context:
-            return self.context[var_name]
-        else:
-            return '255.255.255.0'
+    def get_dns(self, dev):
+        return self.get_field(dev, "dns", "").split()
 
-    def get_network(self, dev, components):
-        var_name = dev.upper() + '_NETWORK'
-        if var_name in self.context:
-            return self.context[var_name]
-        else:
-            return '.'.join(components[:-1]) + '.0'
+    def get_domain(self, dev):
+        return self.get_field(dev, "domain")
+
+    def get_ip(self, dev, mac):
+        return self.get_field(dev, "ip", self.mac2ip(mac))
 
     def get_gateway(self, dev):
-        var_name = dev.upper() + '_GATEWAY'
-        if var_name in self.context:
-            return self.context[var_name]
-        else:
-            return None
+        return self.get_field(dev, "gateway")
 
-    def get_dns(self, dev):
-        var_name = dev.upper() + '_DNS'
-        if var_name in self.context:
-            return self.context[var_name]
-        else:
-            return None
+    def get_mask(self, dev):
+        return self.get_field(dev, "mask", "255.255.255.0")
 
-    def get_domain(self, dev):
-        var_name = dev.upper() + '_DOMAIN'
-        if var_name in self.context:
-            return self.context[var_name]
-        else:
-            return None
+    def get_network(self, dev, mac):
+        return self.get_field(dev, "network", self.mac2network(mac))
+
+    def get_field(self, dev, name, default=None):
+        """return the field name in context for device dev.
+
+        context stores <dev>_<NAME> (example: eth0_DOMAIN).
+        an empty string for value will return default."""
+        val = self.context.get('_'.join((dev, name,)).upper())
+        # allow empty string to return the default.
+        return default if val in (None, "") else val
 
     def gen_conf(self):
-        global_dns = []
-        if 'DNS' in self.context:
-            global_dns.append(self.context['DNS'])
+        global_dns = self.context.get('DNS', "").split()
 
         conf = []
         conf.append('auto lo')
@@ -175,29 +179,31 @@ class OpenNebulaNetwork(object):
         conf.append('')
 
         for mac, dev in self.ifaces.items():
-            ip_components = self.mac2ip(mac)
+            mac = mac.lower()
+
+            # c_dev stores name in context 'ETHX' for this device.
+            # dev stores the current system name.
+            c_dev = self.context_devname.get(mac, dev)
 
             conf.append('auto ' + dev)
             conf.append('iface ' + dev + ' inet static')
-            conf.append('  address ' + self.get_ip(dev, ip_components))
-            conf.append('  network ' + self.get_network(dev, ip_components))
-            conf.append('  netmask ' + self.get_mask(dev))
+            conf.append('  #hwaddress %s' % mac)
+            conf.append('  address ' + self.get_ip(c_dev, mac))
+            conf.append('  network ' + self.get_network(c_dev, mac))
+            conf.append('  netmask ' + self.get_mask(c_dev))
 
-            gateway = self.get_gateway(dev)
+            gateway = self.get_gateway(c_dev)
             if gateway:
                 conf.append('  gateway ' + gateway)
 
-            domain = self.get_domain(dev)
+            domain = self.get_domain(c_dev)
             if domain:
                 conf.append('  dns-search ' + domain)
 
             # add global DNS servers to all interfaces
-            dns = self.get_dns(dev)
+            dns = self.get_dns(c_dev)
             if global_dns or dns:
-                all_dns = global_dns
-                if dns:
-                    all_dns.append(dns)
-                conf.append('  dns-nameservers ' + ' '.join(all_dns))
+                conf.append('  dns-nameservers ' + ' '.join(global_dns + dns))
 
             conf.append('')