Fixed config file issues in which one could not pass a file using simulaqron start ... -network-config-file FILE

In doing so, we also demand the correct network config being passes to start_vnode etc instead of relying from
unclear reads later on

Some tests have been adapted since Network from network.py now takes another argument

Author: StephanieWehner

examples/distributed/teleport/simulaqron_network.json

@@ -11,12 +11,12 @@
             },
             {
                 "Bob": {
-                    "app_socket": ["localhost", 8831],
-                    "qnodeos_socket": ["localhost", 8832],
-                    "vnode_socket": ["localhost", 8833]
+                    "app_socket": ["localhost", 9831],
+                    "qnodeos_socket": ["localhost", 9832],
+                    "vnode_socket": ["localhost", 9833]
                 }
             }
         ],
         "topology": null
     }
-]
+]

examples/distributed/teleport/teleport-alice.py

@@ -2,7 +2,7 @@
 set_simulator("simulaqron")
 
 from simulaqron.settings import simulaqron_settings
-simulaqron_settings.network_config_file = "./networkConfig.json"
+simulaqron_settings.network_config_file = "./simulaqron_settings.json"
 
 from netqasm.sdk.external import NetQASMConnection
 from netqasm.sdk import Qubit, EPRSocket

examples/distributed/teleport/teleport-bob.py

@@ -2,7 +2,7 @@
 set_simulator("simulaqron")
 
 from simulaqron.settings import simulaqron_settings
-simulaqron_settings.network_config_file = "./networkConfig.json"
+simulaqron_settings.network_config_file = "./simulaqron_settings.json"
 
 from netqasm.sdk.external import NetQASMConnection
 from netqasm.sdk import EPRSocket

examples/nativeMode/corrRNG/run.sh

@@ -2,7 +2,7 @@
 
 # Check if SimulaQron is already running
 if [ ! -f ~/.simulaqron_pids/simulaqron_network_default.pid ]; then
-    simulaqron start --nodes=Alice,Bob --force
+    simulaqron start --nodes=Alice,Bob --network-config-file classicalNet.json
 fi
 
 python3 bobTest.py &

simulaqron/network.py

@@ -35,6 +35,7 @@
 import networkx as nx
 from multiprocess.context import ForkProcess as Process
 import logging
+from pathlib import Path
 
 from simulaqron.settings import network_config
 from simulaqron.settings.network_config import NodeConfig
@@ -52,17 +53,22 @@
 
 
 class Network:
-    def __init__(self, nodes: List[str], network_name: str = "default"):
+    def __init__(self, nodes: List[str], network_config_file: Path, network_name: str = "default"):
         """
         Used to spin up a simulated network.
         This class uses the network configuration loaded in the global network_config object and
         starts the nodes mentioned in the constructor of this class.
 
         :param network_name: str
             The name of network to start. Defaults to "default".
+        :param network_config_file: Path
+            Path to network config file (required).
         :param nodes: list of str
             A list of strings with the node names to start.
         """
+
+        self._network_config_file = network_config_file
+
         self._running = False
         self.name = network_name
 
@@ -111,10 +117,14 @@ def _setup_processes(self):
         """
         for node in self._nodes_to_start:
             process_virtual = Process(
-                target=start_vnode, args=(node.name, self.name, simulaqron_settings.log_level), name=f"VirtNode {node.name}"
+                target=start_vnode, 
+                args=(node.name, self._network_config_file, self.name, simulaqron_settings.log_level),
+                name=f"VirtNode {node.name}"
             )
             process_qnodeos = Process(
-                target=start_qnodeos, args=(node.name, self.name, simulaqron_settings.log_level), name=f"QnodeOSNode {node.name}"
+                target=start_qnodeos, 
+                args=(node.name, self._network_config_file, self.name, simulaqron_settings.log_level),
+                name=f"QnodeOSNode {node.name}"
             )
             self.processes += [process_virtual, process_qnodeos]
 

simulaqron/run/run.py

@@ -26,6 +26,7 @@
 from simulaqron.network import Network
 from simulaqron.sdk import SimulaQronConnection
 from simulaqron.settings import simulaqron_settings, network_config
+from simulaqron.settings import get_default_network_config_file
 from simulaqron.settings.simulaqron_config import SimBackend
 
 logger = logging.getLogger()
@@ -183,19 +184,22 @@ def run_applications(
         app_instance.logging_cfg.comm_log_dir = timed_log_dir
 
     results: List[Dict[str, Any]] = []
-    if isinstance(network_cfg, str) or isinstance(network_cfg, PathLike):
-        net_cfg = str(network_cfg)
-        network_config.read_from_file(net_cfg)
-    elif isinstance(network_cfg, Path):
-        net_cfg = str(network_cfg.resolve())
-        network_config.read_from_file(net_cfg)
-    else:
-        # If no network config file was given, we keep with the default-loaded (pwd, or home)
-        pass
 
-    for _ in range(num_rounds):
-        network = Network(network_name="default", nodes=network_config.get_node_names("default"))
+    # Read the network config
+    if network_cfg is None:
+        network_cfg = get_default_network_config_file()
+   
+    network_cfg = Path(network_cfg).resolve()
+    network_config.read_from_file(network_cfg)
+    network_config.read_from_file(network_cfg)
+
 
+    for _ in range(num_rounds):
+        network = Network(
+            nodes=network_config.get_node_names("default"),
+            network_config_file=network_cfg,
+            network_name="default",
+        )
         # Start the processes that support the simulator: QNodeOS + VirtualNode
         network.start()
 

simulaqron/settings/__init__.py

@@ -1,5 +1,6 @@
 from .network_config import (NetworkConfigBuilder, DEFAULT_SIMULAQRON_NETWORK_FILENAME,
-                             LOCAL_NETWORK_SETTINGS, HOME_NETWORK_SETTINGS)
+                             LOCAL_NETWORK_SETTINGS, HOME_NETWORK_SETTINGS,
+                             get_default_network_config_file)
 from .simulaqron_config import (SimulaqronConfig, DEFAULT_SIMULAQRON_SETTINGS_FILENAME,
                                 LOCAL_SIMULAQRON_SETTINGS, HOME_SIMULAQRON_SETTINGS)
 from ._serialization import init_serialization

simulaqron/settings/network_config.py

@@ -169,11 +169,21 @@ class NetworkConfigBuilder(JSONSerializerMixin):
     networks: Dict[str, NetworkConfig] = field(default_factory=dict)
     used_sockets: List[Tuple[str, int]] = field(default_factory=list)
 
+
+
     def using_default_network(self):
+        """
+        Load the embedded default network configuration.
+    
+        Used for test isolation - always loads the embedded default
+        regardless of local config files.
+        """
+
         # We use the embedded default network here
-        default_network_path = resources.files(simulaqron._default_config).joinpath("default_network.json")
+        default_network_path = get_default_network_config_file(use_embedded=True)
+
         new_builder = NetworkConfigBuilder()
-        new_builder.read_from_file(Path(str(default_network_path)))
+        new_builder.read_from_file(default_network_path)
         self.networks = new_builder.networks
         self.used_sockets = new_builder.used_sockets
 
@@ -400,6 +410,7 @@ def read_from_file(self, file_path: PathLike | str):
         :param file_path: None or str
             If a file_path was specified upon __init__ this will be used if file_path is None.
         """
+
         if file_path is None:
             raise ValueError("No path specified to read the network configuration")
 
@@ -429,23 +440,16 @@ def _deserialize_from_file(cls, file_path: Path) -> Self:
 
     @classmethod
     def load_from_known_sources(cls) -> Self:
-        cwd_networks_file = LOCAL_NETWORK_SETTINGS.resolve()
-        home_networks_file = HOME_NETWORK_SETTINGS.resolve()
-
-        files_to_load = [cwd_networks_file, home_networks_file]
-
-        for file in files_to_load:
-            try:
-                if file.exists() and file.is_file():
-                    return cls._deserialize_from_file(file)
-            except json.JSONDecodeError:
-                # Nothing to do; try next one
-                pass
-
-        # Ultimate case; we create a new config file in the home and load it
-        default_net_cfg_path = Path(str(resources.files(simulaqron._default_config).joinpath("default_network.json")))
-        shutil.copyfile(default_net_cfg_path, home_networks_file)
-        return cls._deserialize_from_file(home_networks_file)
+        """
+        Load config from the default config file.
+        
+        Uses :func:`get_default_network_config_file` to resolve the path.
+        
+        :return: Loaded network configuration.
+        :rtype: NetworkConfigBuilder
+        """
+        config_file = get_default_network_config_file()
+        return cls._deserialize_from_file(config_file)
 
     # Helper properties and pythonic accessors
     @property
@@ -515,3 +519,34 @@ def _check_socket_is_free(port: int) -> bool:
             except socket.error:
                 return False
         return True
+
+########### 
+#
+
+def get_default_network_config_file(use_embedded: bool = False) -> Path:
+    """
+    Get the network config file path to use.
+    
+    :param use_embedded: If True, always use the embedded default (for tests).
+        If False, uses priority: LOCAL > HOME > embedded.
+    :type use_embedded: bool
+    :return: Path to the network config file.
+    :rtype: Path
+    """
+
+    # We will use an embedded default which is used in testing
+    if use_embedded:
+        return Path(str(resources.files(simulaqron._default_config).joinpath("default_network.json")))
+   
+    # Implements using the local directory setting as a priority
+    if LOCAL_NETWORK_SETTINGS.exists():
+        return LOCAL_NETWORK_SETTINGS
+    if HOME_NETWORK_SETTINGS.exists():
+        return HOME_NETWORK_SETTINGS
+    
+    # Create default in HOME (matches load_from_known_sources behavior)
+    # XXX I have mixed feelings we should do this, but I leave it for now
+    default_net_cfg_path = Path(str(resources.files(simulaqron._default_config).joinpath("default_network.json")))
+    HOME_NETWORK_SETTINGS.parent.mkdir(parents=True, exist_ok=True)
+    shutil.copyfile(default_net_cfg_path, HOME_NETWORK_SETTINGS)
+    return HOME_NETWORK_SETTINGS

simulaqron/simulaqron.py

@@ -11,7 +11,7 @@
 
 from simulaqron.network import Network
 from simulaqron.settings import LOCAL_SIMULAQRON_SETTINGS, LOCAL_NETWORK_SETTINGS, HOME_NETWORK_SETTINGS
-from simulaqron.settings import simulaqron_settings, network_config
+from simulaqron.settings import simulaqron_settings, get_default_network_config_file, network_config
 from simulaqron.settings.network_config import NodeConfig, DEFAULT_SIMULAQRON_NETWORK_FILENAME
 from simulaqron.settings.simulaqron_config import SimBackend
 
@@ -38,12 +38,41 @@ def __init__(self, pidfile: Path):
         )
 
 class SimulaQronDaemon(run.RunDaemon):
-    def __init__(self, pidfile: Path, name: str, nodes: List[str]):
+    """
+    Daemon process that runs a SimulaQron network in the background.
+
+    This daemon spawns virtual nodes and QNodeOS servers for each node
+    in the network configuration. It runs until explicitly stopped.
+
+    Attributes
+    ----------
+    name : str
+        Name of the network (e.g., 'default').
+    nodes : List[str]
+        List of node names to start (e.g., ['Alice', 'Bob']).
+    network_config_file : Path
+        Path to the network configuration JSON file.
+    """
+    def __init__(self, pidfile: Path, name: str, nodes: List[str], network_config_file: Path):
+        """
+        Initialize the SimulaQron daemon.
+
+        :param pidfile: Path to the PID file used to track the daemon process.
+        :type pidfile: Path
+        :param name: Name of the network (e.g., 'default').
+        :type name: str
+        :param nodes: List of node names to start (e.g., ['Alice', 'Bob']).
+        :type nodes: List[str]
+        :param network_config_file: Path to the network configuration file.
+        :type network_config_file: Path
+        
+        """
         super().__init__(
             pidfile=pidfile,
         )
         self.name = name
         self.nodes = nodes
+        self.network_config_file = network_config_file
 
     def run(self):
         """Starts all nodes defined in netsim's config directory."""
@@ -52,7 +81,15 @@ def run(self):
         sys.stdout = open('/tmp/simulaqron.out', 'w', buffering=1)
         sys.stderr = open('/tmp/simulaqron.err', 'w', buffering=1)
 
-        network = Network(network_name=self.name, nodes=self.nodes)
+        # Let's read the config file we should be working from
+        network_config.read_from_file(self.network_config_file)
+
+        # Start the network to be simulated on this node
+        network = Network(
+            nodes=self.nodes,
+            network_config_file=self.network_config_file,
+            network_name=self.name,
+        )
         network.start()
 
         while True:
@@ -87,7 +124,7 @@ def version():
     help=f"Use the given network config file. Defaults to the file named "  # noqa: E131
          f"'{DEFAULT_SIMULAQRON_NETWORK_FILENAME}' on the current directory.",  # noqa: E131
     type=click.Path(exists=True, dir_okay=False, resolve_path=True, path_type=Path),
-    default=LOCAL_NETWORK_SETTINGS
+    default=None
 )
 @click.option(
     "--name",
@@ -112,7 +149,13 @@ def version():
 )
 def start(name: str, nrnodes: int, nodes: str, network_config_file: Path):
     """Starts a network with the given parameters or from config files."""
-    network_config.read_from_file(network_config_file)
+
+    # Read the network configuration from the indicated file
+    if network_config_file is None:
+        network_config_file = get_default_network_config_file()
+    elif not network_config_file.exists():
+        raise click.BadParameter(f"File '{network_config_file}' does not exist.")
+
     pidfile = PID_FOLDER / f"simulaqron_network_{name}.pid"
     if pidfile.exists():
         logging.warning("Network with name %s is already running", name)
@@ -124,7 +167,10 @@ def start(name: str, nrnodes: int, nodes: str, network_config_file: Path):
               "this can be normal. Please check your invocation line if needed.")
     if nrnodes > 0 and len(nodes) < nrnodes:
         nodes += [f"Node{i}" for i in range(nrnodes - len(nodes))]
-    d = SimulaQronDaemon(pidfile=pidfile, name=name, nodes=nodes)
+
+    # Let's start the simulaqron daemon. We will pass the config file so it will be available
+    # in the child process and load the same config
+    d = SimulaQronDaemon(pidfile=pidfile, name=name, nodes=nodes, network_config_file=network_config_file)
     try:
         d.start()
     except SystemExit as e:

simulaqron/start/start_qnodeos.py

@@ -9,6 +9,7 @@
 import logging
 from twisted.internet.error import ConnectionRefusedError, CannotListenError
 from twisted.spread import pb
+from pathlib import Path
 
 from simulaqron.reactor import reactor
 from simulaqron.netqasm_backend.factory import NetQASMFactory
@@ -121,7 +122,24 @@ def sigterm_handler(_signo, _stack_frame):
     reactor.stop()
 
 
-def start_qnodeos(node_name: str, network_name: str = "default", log_level: str = "WARNING"):
+def start_qnodeos(node_name: str, network_config_file: Path, network_name: str = "default", log_level: str = "WARNING"):
+    """
+    Start the QNPU that accepts NetQASM subroutines, and sends them as instructions to the SimulaQron virtual node
+    backend over twisted PB (Native Mode SimulaQron).
+    
+    :param name: Name of the node (e.g., 'Alice').
+    :type name: str
+    :param network_config_file: Path to network config file.
+    :type network_config_file: Path
+    :param network_name: Name of the network (e.g., 'default').
+    :type network_name: str
+    :param log_level: Logging level (e.g., 'DEBUG', 'INFO', 'WARNING').
+    :type log_level: str
+    """
+
+    # Let's ensure we read the config file
+    network_config.read_from_file(network_config_file)
+
     if simulaqron_settings.log_level == logging.DEBUG:
         global stdout_file
         stdout_file = open(f"/tmp/simulaqron-stdout-stderr-qnos-{node_name}-{os.getpid()}.out.txt", "w")