fixes #11

This commit address an issue where an exception is raised if an ip interface
was not configured with an MTU value.  The config parser will now properly
parse the interface configuration and return the value of the mtu setting.

pyeapi/api/ipinterfaces.py

@@ -51,21 +51,19 @@
 
 
 SWITCHPORT_RE = re.compile(r'^\s{3}switchport$', re.M)
-IPADDR_RE = re.compile(r'(?<=\s{3}ip\saddress\s)(?P<value>.+)$', re.M)
-MTU_RE = re.compile(r'(?<=\s{3}mtu\s)(?P<value>\d+)$', re.M)
-
 
 class Ipinterfaces(EntityCollection):
 
     def get(self, name):
         """Returns the specific IP interface properties
 
-        Example
-            {
-                "name": <string>,
-                "address": <string>,
-                "mtu": <integer>
-            }
+        The Ipinterface resource returns the following:
+
+            * name (str): The name of the interface
+            * address (str): The IP address of the interface in the form
+                of A.B.C.D/E
+            * mtu (int): The configured value for IP MTU.
+
 
         Args:
             name (string): The interface identifier to retrieve the
@@ -81,14 +79,43 @@ def get(self, name):
         if SWITCHPORT_RE.search(config, re.M):
             return None
 
-        resp = dict(name=name)
+        resource = dict(name=name)
+        resource.update(self._parse_address(config))
+        resource.update(self._parse_mtu(config))
+        return resource
+
+    def _parse_address(self, config):
+        """Parses the config block and returns the ip address value
+
+        The provided configuration block is scaned and the configured value
+        for the IP address is returned as a dict object.  If the IP address
+        value is not configured, then None is returned for the value
+
+        Args:
+            config (str): The interface configuration block to parse
+
+        Return:
+            dict: A dict object intended to be merged into the resource dict
+        """
+        match = re.search(r'ip address ([^\s]+)', config)
+        value = match.group(1) if match else None
+        return dict(address=value)
 
-        value = lambda x, y: x.group('value') if x else y
+    def _parse_mtu(self, config):
+        """Parses the config block and returns the configured IP MTU value
 
-        resp['address'] = value(IPADDR_RE.search(config, re.M), '0.0.0.0')
-        resp['mtu'] = int(MTU_RE.search(config, re.M).group('value'))
+        The provided configuration block is scanned and the configured value
+        for the IP MTU is returned as a dict object.  The IP MTU value is
+        expected to always be present in the provided config block
 
-        return resp
+        Args:
+            config (str): The interface configuration block to parse
+
+        Return:
+            dict: A dict object intended to be merged into the resource dict
+        """
+        match = re.search(r'mtu (\d+)', config)
+        return dict(mtu=int(match.group(1)))
 
     def getall(self):
         """ Returns all of the IP interfaces found in the running-config

test/system/test_api_ipinterfaces.py

@@ -57,7 +57,7 @@ def test_get_interface_wo_ip_adddress(self):
             dut.config(['default interface %s' % intf, 'interface %s' % intf,
                         'no switchport'])
             result = dut.api('ipinterfaces').get(intf)
-            self.assertEqual(result['address'], '0.0.0.0')
+            self.assertIsNone(result['address'])
 
     def test_getall(self):
         for dut in self.duts: