zeroconf: add module for zeroconf discovery

Signed-off-by: Clifford Roche <clifford.roche@gmail.com>

docs/configuration.md

@@ -842,4 +842,14 @@ gcode:
                                strip=strip,
                                red=red, green=green, blue=blue, white=white,
                                index=index, transmit=transmit)}
-```
+```
+
+### `[zeroconf]`
+Enable Zeroconf service registration allowing external services to more
+easily detect and use Moonraker instances.
+
+```ini
+# moonraker.conf
+
+[zeroconf]
+```

moonraker/components/zeroconf.py

@@ -0,0 +1,59 @@
+# Zeroconf registration implementation for Moonraker
+#
+# Copyright (C) 2021  Eric Callahan <arksine.code@gmail.com>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+from __future__ import annotations
+import socket
+import asyncio
+
+from zeroconf import IPVersion
+from zeroconf.asyncio import AsyncServiceInfo, AsyncZeroconf
+
+from typing import TYPE_CHECKING, List, Optional
+if TYPE_CHECKING:
+    from confighelper import ConfigHelper
+
+class AsyncRunner:
+    def __init__(self, ip_version: IPVersion) -> None:
+        self.ip_version = ip_version
+        self.aiozc: Optional[AsyncZeroconf] = None
+
+    async def register_services(self, infos: List[AsyncServiceInfo]) -> None:
+        self.aiozc = AsyncZeroconf(ip_version=self.ip_version)
+        tasks = [self.aiozc.async_register_service(info) for info in infos]
+        background_tasks = await asyncio.gather(*tasks)
+        await asyncio.gather(*background_tasks)
+
+    async def unregister_services(self, infos: List[AsyncServiceInfo]) -> None:
+        assert self.aiozc is not None
+        tasks = [self.aiozc.async_unregister_service(info) for info in infos]
+        background_tasks = await asyncio.gather(*tasks)
+        await asyncio.gather(*background_tasks)
+        await self.aiozc.async_close()
+
+class ZeroconfRegistrar():
+    def __init__(self, config: ConfigHelper) -> None:
+        self.server = config.get_server()
+        self.event_loop = self.server.get_event_loop()
+
+        host_name, port = self.server.get_host_info()
+        addresses = [socket.gethostbyname(host_name)]
+        self.service_info = AsyncServiceInfo(
+            "_moonraker._tcp.local.",
+            f"{host_name}._moonraker._tcp.local.",
+            addresses=addresses,
+            port=port,
+            properties={'path': '/'},
+            server=f"{host_name}.local."
+        )
+        self.runner = AsyncRunner(IPVersion.All)
+
+    async def component_init(self):
+        await self.runner.register_services([self.service_info])
+
+    async def close(self) -> None:
+        await self.runner.unregister_services([self.service_info])
+
+def load_component(config: ConfigHelper) -> ZeroconfRegistrar:
+    return ZeroconfRegistrar(config)

scripts/moonraker-requirements.txt

@@ -9,3 +9,4 @@ inotify-simple==1.3.5
 libnacl==1.7.2
 paho-mqtt==1.5.1
 pycurl==7.44.1
+zeroconf==0.37.0