Nat node work on any linux thanks to libvirt

Fix #599

tests/compute/builtin/nodes/test_nat.py

@@ -31,8 +31,8 @@ def test_json(on_gns3vm, project):
         "status": "started",
         "ports": [
             {
-                "interface": "eth1",
-                "name": "nat0",
+                "interface": "virbr0",
+                "name": "virbr0",
                 "port_number": 0,
                 "type": "ethernet"
             }

tests/conftest.py

@@ -315,10 +315,10 @@ def async_run(loop):
 
 
 @pytest.yield_fixture
-def on_gns3vm():
+def on_gns3vm(linux_platform):
     """
     Mock the hostname to  emulate the GNS3 VM
     """
-    with patch("gns3server.utils.interfaces.interfaces", return_value=[{"name": "eth0"}, {"name": "eth1"}]):
+    with patch("gns3server.utils.interfaces.interfaces", return_value=[{"name": "eth0"}, {"name": "eth1", "name": "virbr0"}]):
         with patch("socket.gethostname", return_value="gns3vm"):
             yield