fix(MDL): Throw on faulty pipeline connection address

See merge request Karabo/Framework!8138

src/pythonKarabo/karabo/middlelayer/pipeline.py

@@ -48,21 +48,19 @@
 def get_hostname_from_interface(address_range):
     """returns the ip address of the local interfaces
 
-    in case of bad input, it will return the result of
-    `socket.gethostname()`
+    in case of bad input, it will throw
     """
-    try:
-        network = ip_network(address_range)
-        for interface in net_if_addrs().values():
-            for nic in interface:
-                if nic.family != socket.AF_INET:
-                    continue
-                addr = ip_address(nic.address)
-                if addr in network:
-                    return nic.address
-    except ValueError:
-        pass
-    return socket.gethostname()
+    # ip_network will throw if address cannot be found
+    network = ip_network(address_range)
+    for interface in net_if_addrs().values():
+        for nic in interface:
+            if nic.family != socket.AF_INET:
+                continue
+            addr = ip_address(nic.address)
+            if addr in network:
+                return nic.address
+    raise ValueError(
+        f"{address_range} does not appear to be an IPv4 or IPv6 network")
 
 
 class CancelQueue(Queue):
@@ -1202,6 +1200,7 @@ def toDataAndAttrs(self, instance):
 
 
 class OutputChannel(Node):
+
     def __init__(self, cls=None, **kwargs):
         if cls is None:
             # Child check for output schema

src/pythonKarabo/karabo/middlelayer/tests/remote_pipeline_test.py

@@ -20,9 +20,9 @@
 
 from karabo.middlelayer import (
     AccessLevel, AccessMode, Assignment, Bool, Configurable, Device, Hash,
-    InputChannel, Int32, Node, OutputChannel, Overwrite, PipelineContext,
-    PipelineMetaData, Slot, State, Timestamp, UInt32, background, call,
-    getDevice, getSchema, isAlive, setWait, slot, waitUntil)
+    InputChannel, Int32, NetworkOutput, Node, OutputChannel, Overwrite,
+    PipelineContext, PipelineMetaData, Slot, State, Timestamp, UInt32,
+    background, call, getDevice, getSchema, isAlive, setWait, slot, waitUntil)
 from karabo.middlelayer.testing import AsyncDeviceContext, run_test, sleepUntil
 
 FIXED_TIMESTAMP = Timestamp("2009-04-20T10:32:22 UTC")
@@ -876,3 +876,23 @@ def new_connect_handler(channel):
             await wait_for(waitUntil(lambda: input_proxy.received > 0),
                            timeout=timeout)
             assert receiver.received > 0
+
+
+@pytest.mark.timeout(30)
+@run_test
+async def test_output_fail_address(event_loop):
+    """Test the output with a wrong address"""
+
+    class Output(NetworkOutput):
+        hostname = Overwrite(defaultValue="192.168.1/22")
+
+    class SimpleSender(Device):
+
+        output = Node(Output)
+
+    config = {"_deviceId_": "outputraisedevice"}
+
+    output_device = SimpleSender(config)
+    with pytest.raises(ValueError) as exc:
+        await output_device.startInstance()
+    assert "does not appear to be an IPv4 or IPv6 network" in str(exc)