net,Oracle: Add support for netfailover detection

Add support for detecting netfailover[1] device 3-tuple in networking
layer.  In the Oracle datasource ensure that if a provided network
config, either fallback or provided config includes a netfailover master
to remove any MAC address value as this can break under 3-netdev
as the other two devices have the same MAC.

1. https://www.kernel.org/doc/html/latest/networking/net_failover.html

2 files changed, 208 insertions, 1 deletions

diff --git a/cloudinit/sources/DataSourceOracle.py b/cloudinit/sources/DataSourceOracle.py
index 1cb0636c..eec87403 100644
--- a/cloudinit/sources/DataSourceOracle.py
+++ b/cloudinit/sources/DataSourceOracle.py
@@ -16,7 +16,7 @@ Notes:
 """
 
 from cloudinit.url_helper import combine_url, readurl, UrlError
-from cloudinit.net import dhcp, get_interfaces_by_mac
+from cloudinit.net import dhcp, get_interfaces_by_mac, is_netfail_master
 from cloudinit import net
 from cloudinit import sources
 from cloudinit import util
@@ -108,6 +108,56 @@ def _add_network_config_from_opc_imds(network_config):
                 'match': {'macaddress': mac_address}}
 
 
+def _ensure_netfailover_safe(network_config):
+    """
+    Search network config physical interfaces to see if any of them are
+    a netfailover master.  If found, we prevent matching by MAC as the other
+    failover devices have the same MAC but need to be ignored.
+
+    Note: we rely on cloudinit.net changes which prevent netfailover devices
+    from being present in the provided network config.  For more details about
+    netfailover devices, refer to cloudinit.net module.
+
+    :param network_config
+       A v1 or v2 network config dict with the primary NIC, and possibly
+       secondary nic configured.  This dict will be mutated.
+
+    """
+    # ignore anything that's not an actual network-config
+    if 'version' not in network_config:
+        return
+
+    if network_config['version'] not in [1, 2]:
+        LOG.debug('Ignoring unknown network config version: %s',
+                  network_config['version'])
+        return
+
+    mac_to_name = get_interfaces_by_mac()
+    if network_config['version'] == 1:
+        for cfg in [c for c in network_config['config'] if 'type' in c]:
+            if cfg['type'] == 'physical':
+                if 'mac_address' in cfg:
+                    mac = cfg['mac_address']
+                    cur_name = mac_to_name.get(mac)
+                    if not cur_name:
+                        continue
+                    elif is_netfail_master(cur_name):
+                        del cfg['mac_address']
+
+    elif network_config['version'] == 2:
+        for _, cfg in network_config.get('ethernets', {}).items():
+            if 'match' in cfg:
+                macaddr = cfg.get('match', {}).get('macaddress')
+                if macaddr:
+                    cur_name = mac_to_name.get(macaddr)
+                    if not cur_name:
+                        continue
+                    elif is_netfail_master(cur_name):
+                        del cfg['match']['macaddress']
+                        del cfg['set-name']
+                        cfg['match']['name'] = cur_name
+
+
 class DataSourceOracle(sources.DataSource):
 
     dsname = 'Oracle'
@@ -208,9 +258,13 @@ class DataSourceOracle(sources.DataSource):
         We nonetheless return cmdline provided config if present
         and fallback to generate fallback."""
         if self._network_config == sources.UNSET:
+            # this is v1
             self._network_config = cmdline.read_initramfs_config()
+
             if not self._network_config:
+                # this is now v2
                 self._network_config = self.distro.generate_fallback_config()
+
             if self.ds_cfg.get('configure_secondary_nics'):
                 try:
                     # Mutate self._network_config to include secondary VNICs
@@ -219,6 +273,12 @@ class DataSourceOracle(sources.DataSource):
                     util.logexc(
                         LOG,
                         "Failed to fetch secondary network configuration!")
+
+            # we need to verify that the nic selected is not a netfail over
+            # device and, if it is a netfail master, then we need to avoid
+            # emitting any match by mac
+            _ensure_netfailover_safe(self._network_config)
+
         return self._network_config
 
 
diff --git a/cloudinit/sources/tests/test_oracle.py b/cloudinit/sources/tests/test_oracle.py
index 2a70bbc9..85b6db97 100644
--- a/cloudinit/sources/tests/test_oracle.py
+++ b/cloudinit/sources/tests/test_oracle.py
@@ -8,6 +8,7 @@ from cloudinit.tests import helpers as test_helpers
 
 from textwrap import dedent
 import argparse
+import copy
 import httpretty
 import json
 import mock
@@ -586,4 +587,150 @@ class TestNetworkConfigFromOpcImds(test_helpers.CiTestCase):
         self.assertEqual('10.0.0.231', secondary_nic_cfg['addresses'][0])
 
 
+class TestNetworkConfigFiltersNetFailover(test_helpers.CiTestCase):
+
+    with_logs = True
+
+    def setUp(self):
+        super(TestNetworkConfigFiltersNetFailover, self).setUp()
+        self.add_patch(DS_PATH + '.get_interfaces_by_mac',
+                       'm_get_interfaces_by_mac')
+        self.add_patch(DS_PATH + '.is_netfail_master', 'm_netfail_master')
+
+    def test_ignore_bogus_network_config(self):
+        netcfg = {'something': 'here'}
+        passed_netcfg = copy.copy(netcfg)
+        oracle._ensure_netfailover_safe(passed_netcfg)
+        self.assertEqual(netcfg, passed_netcfg)
+
+    def test_ignore_network_config_unknown_versions(self):
+        netcfg = {'something': 'here', 'version': 3}
+        passed_netcfg = copy.copy(netcfg)
+        oracle._ensure_netfailover_safe(passed_netcfg)
+        self.assertEqual(netcfg, passed_netcfg)
+
+    def test_checks_v1_type_physical_interfaces(self):
+        mac_addr, nic_name = '00:00:17:02:2b:b1', 'ens3'
+        self.m_get_interfaces_by_mac.return_value = {
+            mac_addr: nic_name,
+        }
+        netcfg = {'version': 1, 'config': [
+            {'type': 'physical', 'name': nic_name, 'mac_address': mac_addr,
+             'subnets': [{'type': 'dhcp4'}]}]}
+        passed_netcfg = copy.copy(netcfg)
+        self.m_netfail_master.return_value = False
+        oracle._ensure_netfailover_safe(passed_netcfg)
+        self.assertEqual(netcfg, passed_netcfg)
+        self.assertEqual([mock.call(nic_name)],
+                         self.m_netfail_master.call_args_list)
+
+    def test_checks_v1_skips_non_phys_interfaces(self):
+        mac_addr, nic_name = '00:00:17:02:2b:b1', 'bond0'
+        self.m_get_interfaces_by_mac.return_value = {
+            mac_addr: nic_name,
+        }
+        netcfg = {'version': 1, 'config': [
+            {'type': 'bond', 'name': nic_name, 'mac_address': mac_addr,
+             'subnets': [{'type': 'dhcp4'}]}]}
+        passed_netcfg = copy.copy(netcfg)
+        oracle._ensure_netfailover_safe(passed_netcfg)
+        self.assertEqual(netcfg, passed_netcfg)
+        self.assertEqual(0, self.m_netfail_master.call_count)
+
+    def test_removes_master_mac_property_v1(self):
+        nic_master, mac_master = 'ens3', self.random_string()
+        nic_other, mac_other = 'ens7', self.random_string()
+        nic_extra, mac_extra = 'enp0s1f2', self.random_string()
+        self.m_get_interfaces_by_mac.return_value = {
+            mac_master: nic_master,
+            mac_other: nic_other,
+            mac_extra: nic_extra,
+        }
+        netcfg = {'version': 1, 'config': [
+            {'type': 'physical', 'name': nic_master,
+             'mac_address': mac_master},
+            {'type': 'physical', 'name': nic_other, 'mac_address': mac_other},
+            {'type': 'physical', 'name': nic_extra, 'mac_address': mac_extra},
+        ]}
+
+        def _is_netfail_master(iface):
+            if iface == 'ens3':
+                return True
+            return False
+        self.m_netfail_master.side_effect = _is_netfail_master
+        expected_cfg = {'version': 1, 'config': [
+            {'type': 'physical', 'name': nic_master},
+            {'type': 'physical', 'name': nic_other, 'mac_address': mac_other},
+            {'type': 'physical', 'name': nic_extra, 'mac_address': mac_extra},
+        ]}
+        oracle._ensure_netfailover_safe(netcfg)
+        self.assertEqual(expected_cfg, netcfg)
+
+    def test_checks_v2_type_ethernet_interfaces(self):
+        mac_addr, nic_name = '00:00:17:02:2b:b1', 'ens3'
+        self.m_get_interfaces_by_mac.return_value = {
+            mac_addr: nic_name,
+        }
+        netcfg = {'version': 2, 'ethernets': {
+            nic_name: {'dhcp4': True, 'critical': True, 'set-name': nic_name,
+                       'match': {'macaddress': mac_addr}}}}
+        passed_netcfg = copy.copy(netcfg)
+        self.m_netfail_master.return_value = False
+        oracle._ensure_netfailover_safe(passed_netcfg)
+        self.assertEqual(netcfg, passed_netcfg)
+        self.assertEqual([mock.call(nic_name)],
+                         self.m_netfail_master.call_args_list)
+
+    def test_skips_v2_non_ethernet_interfaces(self):
+        mac_addr, nic_name = '00:00:17:02:2b:b1', 'wlps0'
+        self.m_get_interfaces_by_mac.return_value = {
+            mac_addr: nic_name,
+        }
+        netcfg = {'version': 2, 'wifis': {
+            nic_name: {'dhcp4': True, 'critical': True, 'set-name': nic_name,
+                       'match': {'macaddress': mac_addr}}}}
+        passed_netcfg = copy.copy(netcfg)
+        oracle._ensure_netfailover_safe(passed_netcfg)
+        self.assertEqual(netcfg, passed_netcfg)
+        self.assertEqual(0, self.m_netfail_master.call_count)
+
+    def test_removes_master_mac_property_v2(self):
+        nic_master, mac_master = 'ens3', self.random_string()
+        nic_other, mac_other = 'ens7', self.random_string()
+        nic_extra, mac_extra = 'enp0s1f2', self.random_string()
+        self.m_get_interfaces_by_mac.return_value = {
+            mac_master: nic_master,
+            mac_other: nic_other,
+            mac_extra: nic_extra,
+        }
+        netcfg = {'version': 2, 'ethernets': {
+            nic_extra: {'dhcp4': True, 'set-name': nic_extra,
+                        'match': {'macaddress': mac_extra}},
+            nic_other: {'dhcp4': True, 'set-name': nic_other,
+                        'match': {'macaddress': mac_other}},
+            nic_master: {'dhcp4': True, 'set-name': nic_master,
+                         'match': {'macaddress': mac_master}},
+        }}
+
+        def _is_netfail_master(iface):
+            if iface == 'ens3':
+                return True
+            return False
+        self.m_netfail_master.side_effect = _is_netfail_master
+
+        expected_cfg = {'version': 2, 'ethernets': {
+            nic_master: {'dhcp4': True, 'match': {'name': nic_master}},
+            nic_extra: {'dhcp4': True, 'set-name': nic_extra,
+                        'match': {'macaddress': mac_extra}},
+            nic_other: {'dhcp4': True, 'set-name': nic_other,
+                        'match': {'macaddress': mac_other}},
+        }}
+        oracle._ensure_netfailover_safe(netcfg)
+        import pprint
+        pprint.pprint(netcfg)
+        print('---- ^^ modified ^^ ---- vv original vv ----')
+        pprint.pprint(expected_cfg)
+        self.assertEqual(expected_cfg, netcfg)
+
+
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