Nat node is only on the GNS3 VM for the moment

Fix https://github.com/GNS3/gns3-gui/issues/1448

gns3server/compute/builtin/__init__.py

@@ -21,7 +21,7 @@ Builtin nodes server module.
 
 
 from ..base_manager import BaseManager
-from .builtin_node_factory import BuiltinNodeFactory
+from .builtin_node_factory import BuiltinNodeFactory, BUILTIN_NODES
 
 import logging
 log = logging.getLogger(__name__)
@@ -40,4 +40,7 @@ class Builtin(BaseManager):
         """
         :returns: List of node type supported by this class and computer
         """
-        return ['cloud', 'nat', 'ethernet_hub', 'ethernet_switch']
+        types = ['cloud', 'ethernet_hub', 'ethernet_switch']
+        if BUILTIN_NODES['nat'].is_supported():
+            types.append('nat')
+        return types

gns3server/compute/builtin/nodes/nat.py

@@ -41,6 +41,10 @@ class Nat(Cloud):
             }
         ]
 
+    @classmethod
+    def is_supported(self):
+        return socket.gethostname() == "gns3vm"
+
     def __json__(self):
         return {
             "name": self.name,

tests/handlers/api/compute/test_capabilities.py

@@ -26,6 +26,15 @@ from gns3server.version import __version__
 
 
 def test_get(http_compute):
+    """
+    Nat is not supported outside the GNS3VM
+    """
     response = http_compute.get('/capabilities', example=True)
     assert response.status == 200
-    assert response.json == {'node_types': ['cloud', 'nat', 'ethernet_hub', 'ethernet_switch', 'vpcs', 'virtualbox', 'dynamips', 'frame_relay_switch', 'atm_switch', 'qemu', 'vmware', 'docker', 'iou'], 'version': __version__}
+    assert response.json == {'node_types': ['cloud', 'ethernet_hub', 'ethernet_switch', 'vpcs', 'virtualbox', 'dynamips', 'frame_relay_switch', 'atm_switch', 'qemu', 'vmware', 'docker', 'iou'], 'version': __version__}
+
+
+def test_get_on_gns3vm(http_compute, on_gns3vm):
+    response = http_compute.get('/capabilities', example=True)
+    assert response.status == 200
+    assert response.json == {'node_types': ['cloud', 'ethernet_hub', 'ethernet_switch', 'nat', 'vpcs', 'virtualbox', 'dynamips', 'frame_relay_switch', 'atm_switch', 'qemu', 'vmware', 'docker', 'iou'], 'version': __version__}