Implement file-based configuration of multiple servers

README.md

@@ -2,4 +2,19 @@
 
 A tool to replay / proxy data across sockets.  Like a daemonized `socat` of sorts.
 
-Currently a work in progress at this stage.
+## Configuration
+
+Create a TOML file with the following:
+
+```
+[[proxies]]
+# service will listen on this socket for incoming connections
+listen.host = '127.0.16.5'
+listen.port = 50007
+
+# service will pass data between incoming connections and this socket
+forward.host = '127.0.16.5'
+forward.port = 8080
+
+# multiple [[proxies]] sections can be specified
+```

netnsplice/__main__.py

@@ -1,40 +1,44 @@
 #!/usr/bin/python3
 
 import argparse
-import socket
+import pathlib
 import socketserver
 import threading
+import time
+import tomli
 
+from .config import AppConfig
 from .proxy import ProxyStreamRequestHandlerFactory
 
 
 def main():
-    # this is a temporary setup to avoid having hardcoded args in commit history
     parser = argparse.ArgumentParser(description="Proxies data between addresses")
-    parser.add_argument("listen_host")
-    parser.add_argument("listen_port", type=int)
-
-    parser.add_argument("forward_host")
-    parser.add_argument("forward_port", type=int)
+    parser.add_argument("config", type=pathlib.Path)
 
     args = parser.parse_args()
 
-    listen_addr = (args.listen_host, args.listen_port)
-    forward_addr = (args.forward_host, args.forward_port)
-
-    handler = ProxyStreamRequestHandlerFactory(socket.AF_INET, forward_addr)
-    with socketserver.ThreadingTCPServer(listen_addr, handler) as server:
-        server_thread = threading.Thread(target=server.serve_forever)
-        server_thread.start()
-
-        # allow clean interrupts
-        try:
-            while server_thread.is_alive():
-                server_thread.join(0.5)
-        except (KeyboardInterrupt, SystemExit):
-            pass
-        finally:
-            server.shutdown()
+    config = AppConfig.parse_obj(tomli.loads(args.config.read_text()))
+
+    servers = []
+    for proxy in config.proxies:
+        handler = ProxyStreamRequestHandlerFactory(proxy.forward.family, proxy.forward.address)
+        server = socketserver.ThreadingTCPServer(proxy.listen.address, handler)
+
+        thread = threading.Thread(target=server.serve_forever)
+        thread.start()
+
+        servers.append(server)
+
+    # allow clean interrupts
+    try:
+        while True:
+            time.sleep(0.5)
+    except (KeyboardInterrupt, SystemExit):
+        pass
+
+    # shutdown listeners
+    for server in servers:
+        server.shutdown()
 
 
 if __name__ == "__main__":

netnsplice/config.py

@@ -0,0 +1,26 @@
+#!/usr/bin/python3
+
+import pydantic
+import socket
+
+
+class NetSocketConfig(pydantic.BaseModel):
+    host: str
+    port: int
+
+    @property
+    def address(self):
+        return (self.host, self.port)
+
+    @property
+    def family(self) -> socket.AddressFamily:
+        return socket.AF_INET
+
+
+class ProxyConfig(pydantic.BaseModel):
+    listen: NetSocketConfig
+    forward: NetSocketConfig
+
+
+class AppConfig(pydantic.BaseModel):
+    proxies: list[ProxyConfig]

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = netnsplice
-version = 0.0.1
+version = 0.1.0
 author = nosoop
 description = Relays content across nework or file sockets
 long_description = file: README.md
@@ -15,3 +15,6 @@ classifiers =
 [options]
 packages = find:
 python_requires = >= 3.7
+install_requires =
+    tomli
+    pydantic>=1.10.0