Enable windows support by isolating ioctl calls (#233)

* Enable windows support by isolating ioctl calls

Signed-off-by: Etienne Carriere <[email protected]>

* Remove the case when its returns anything but an IP

Signed-off-by: Etienne Carriere <[email protected]>

* Add basic tests for get_local_ip_by_socket

Signed-off-by: Etienne Carriere <[email protected]>

Author: Etienne-Carriere

jaeger_client/utils.py

@@ -12,12 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from six.moves import range
-
-import fcntl
 import socket
 import struct
+
 import time
+from six.moves import range
 
 
 class ErrorReporter(object):
@@ -65,27 +64,54 @@ def local_ip():
     except IOError:
         ip = socket.gethostbyname('localhost')
     if ip.startswith('127.'):
-        # Check eth0, eth1, eth2, en0, ...
-        interfaces = [
-            i + bytes(n) for i in (b'eth', b'en', b'wlan') for n in range(3)
-        ]  # :(
-        for interface in interfaces:
-            try:
-                ip = interface_ip(interface)
+        ip = get_local_ip_by_interfaces()
+        if ip is None:
+            ip = get_local_ip_by_socket()
+    return ip
+
+
+def get_local_ip_by_socket():
+    # Explanation : https://stackoverflow.com/questions/166506
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    try:
+        # doesn't even have to be reachable
+        s.connect(('10.255.255.255', 1))
+        ip = s.getsockname()[0]
+    except IOError:
+        ip = None
+    finally:
+        s.close()
+    return ip
+
+
+def get_local_ip_by_interfaces():
+    ip = None
+    # Check eth0, eth1, eth2, en0, ...
+    interfaces = [
+        i + bytes(n) for i in (b'eth', b'en', b'wlan') for n in range(3)
+    ]  # :(
+    for interface in interfaces:
+        try:
+            ip = interface_ip(interface)
+            if ip is not None:
                 break
-            except IOError:
-                pass
+        except IOError:
+            pass
     return ip
 
 
 def interface_ip(interface):
-    """Determine the IP assigned to us by the given network interface."""
-    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-    return socket.inet_ntoa(
-        fcntl.ioctl(
-            sock.fileno(), 0x8915, struct.pack('256s', interface[:15])
-        )[20:24]
-    )
+    try:
+        import fcntl
+        """Determine the IP assigned to us by the given network interface."""
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        return socket.inet_ntoa(
+            fcntl.ioctl(
+                sock.fileno(), 0x8915, struct.pack('256s', interface[:15])
+            )[20:24]
+        )
+    except ImportError:
+        return None
     # Explanation:
     # http://stackoverflow.com/questions/11735821/python-get-localhost-ip
     # http://stackoverflow.com/questions/24196932/how-can-i-get-the-ip-address-of-eth0-in-python

tests/test_utils.py

@@ -76,3 +76,7 @@ def test_local_ip_does_not_blow_up():
     with mock.patch('socket.gethostbyname',
                     side_effect=[IOError(), '127.0.0.1']):
         jaeger_client.utils.local_ip()
+
+def test_get_local_ip_by_socket_does_not_blow_up():
+    import jaeger_client.utils
+    jaeger_client.utils.get_local_ip_by_socket()