Merge pull request #40 from rackerlabs/list_mac_addrs

RFR: Allow listing of Network Interfaces

teeth_agent/hardware.py

@@ -15,6 +15,7 @@
 """
 
 import abc
+import os
 
 import plumbum
 import stevedore
@@ -43,13 +44,22 @@ def __init__(self, name, size, start_sector):
         self.start_sector = start_sector
 
 
+class NetworkInterface(object):
+    def __init__(self, name, mac_addr):
+        self.name = name
+        self.mac_address = mac_addr
+        # TODO(russellhaering): Pull these from LLDP
+        self.switch_port_descr = None
+        self.switch_chassis_descr = None
+
+
 class HardwareManager(object):
     @abc.abstractmethod
     def evaluate_hardware_support(cls):
         pass
 
     @abc.abstractmethod
-    def get_primary_mac_address(self):
+    def list_network_interfaces(self):
         pass
 
     @abc.abstractmethod
@@ -58,11 +68,32 @@ def get_os_install_device(self):
 
 
 class GenericHardwareManager(HardwareManager):
+    def __init__(self):
+        self.sys_path = '/sys'
+
+        if os.path.isdir('/mnt/sys'):
+            self.sys_path = '/mnt/sys'
+
     def evaluate_hardware_support(cls):
         return HardwareSupport.GENERIC
 
-    def get_primary_mac_address(self):
-        return open('/sys/class/net/eth0/address', 'r').read().strip('\n')
+    def _get_interface_info(self, interface_name):
+        addr_path = '{}/class/net/{}/address'.format(self.sys_path,
+                                                     interface_name)
+        addr_file = open(addr_path, 'r')
+        mac_addr = addr_file.read().strip()
+        return NetworkInterface(interface_name, mac_addr)
+
+    def _is_device(self, interface_name):
+        device_path = '{}/class/net/{}/device'.format(self.sys_path,
+                                                      interface_name)
+        return os.path.exists(device_path)
+
+    def list_network_interfaces(self):
+        iface_names = os.listdir('{}/class/net'.format(self.sys_path))
+        return [self._get_interface_info(name)
+                for name in iface_names
+                if self._is_device(name)]
 
     def _cmd(self, command_name):
         """Mocking plumbum is frustratingly difficult. Instead, mock this."""

teeth_agent/tests/hardware.py

@@ -24,16 +24,20 @@ class TestGenericHardwareManager(unittest.TestCase):
     def setUp(self):
         self.hardware = hardware.GenericHardwareManager()
 
+    @mock.patch('os.listdir')
+    @mock.patch('os.path.exists')
     @mock.patch('__builtin__.open')
-    def test_get_primary_mac_address(self, mocked_open):
-        f = mocked_open.return_value
-        f.read.return_value = '00:0c:29:8c:11:b1\n'
-
-        mac_addr = self.hardware.get_primary_mac_address()
-        self.assertEqual(mac_addr, '00:0c:29:8c:11:b1')
-
-        mocked_open.assert_called_once_with('/sys/class/net/eth0/address', 'r')
-        f.read.assert_called_once_with()
+    def test_list_network_interfaces(self,
+                                     mocked_open,
+                                     mocked_exists,
+                                     mocked_listdir):
+        mocked_listdir.return_value = ['lo', 'eth0']
+        mocked_exists.side_effect = [False, True]
+        mocked_open.return_value.read.return_value = '00:0c:29:8c:11:b1\n'
+        interfaces = self.hardware.list_network_interfaces()
+        self.assertEqual(len(interfaces), 1)
+        self.assertEqual(interfaces[0].name, 'eth0')
+        self.assertEqual(interfaces[0].mac_address, '00:0c:29:8c:11:b1')
 
     def test_get_os_install_device(self):
         self.hardware._cmd = mock.Mock()