ZeroConf

Warnings

• breaking The 1.0.0 release was unintentionally published due to an issue with `python-semantic-release` and was subsequently YANKED. It contained no breaking changes, but users should avoid attempting to install this specific version and instead rely on the latest 0.x.x releases.
  Fix: Ensure your `pip install` command does not explicitly target `zeroconf==1.0.0`. Stick to `zeroconf` or `zeroconf~=0.x.x`.
• gotcha It is crucial to explicitly call the `close()` method on your `Zeroconf` instance(s) when you are done with them. Failing to do so will leave sockets open and consume resources, potentially leading to 'address already in use' errors or resource leaks.
  Fix: Always wrap your `Zeroconf` usage in a `try...finally` block to ensure `zeroconf.close()` is called, as shown in the quickstart example. Consider using `asyncio` for long-running applications or running `Zeroconf` in a dedicated thread.
• gotcha On systems with multiple network interfaces, `zeroconf` might not bind to the desired interface by default. If your service isn't discoverable or you're not seeing other services, explicitly specify the network interfaces to use during `Zeroconf` initialization.
  Fix: Pass a list of interface IPs (e.g., `interfaces=['192.168.1.2', '10.0.0.5']`) to the `Zeroconf` constructor: `zeroconf = Zeroconf(interfaces=my_interfaces)`.

Install

• pip install zeroconf Install stable version

Imports

• Zeroconf

  from zeroconf import Zeroconf

• ServiceInfo

  from zeroconf import ServiceInfo

• ServiceBrowser

  from zeroconf import ServiceBrowser

• ServiceStateChange

  from zeroconf import ServiceStateChange

  Useful for defining a listener for service discovery events.

Quickstart

This quickstart demonstrates how to register a local HTTP service and simultaneously browse for all HTTP services on the network. It registers 'MyTestService' on port 8080 and then listens for 30 seconds, printing any discovered or removed services. Remember to handle `KeyboardInterrupt` and ensure `Zeroconf` instances are properly closed to release network resources.

import socket
import time
from zeroconf import ServiceInfo, Zeroconf, ServiceBrowser

# A simple listener for discovering services
class MyListener:
    def add_service(self, zeroconf_instance, service_type, service_name):
        info = zeroconf_instance.get_service_info(service_type, service_name)
        if info:
            print(f"Service added: {service_name} at {info.server}, Port: {info.port}, Addr: {socket.inet_ntoa(info.addresses[0]) if info.addresses else 'N/A'}")

    def remove_service(self, zeroconf_instance, service_type, service_name):
        print(f"Service removed: {service_name}")

# --- Example Usage ---
zeroconf = None
browser = None
info = None
try:
    # 1. Register a service
    desc = {'path': '/~example'}
    ip_address = socket.gethostbyname(socket.gethostname()) # Or specify an explicit IP like "127.0.0.1"

    info = ServiceInfo(
        "_http._tcp.local.", # Service type
        "MyTestService._http._tcp.local.", # Service name
        addresses=[socket.inet_aton(ip_address)],
        port=8080,
        properties=desc,
        server="example.local.", # The server's hostname
    )

    zeroconf = Zeroconf()
    print(f"Registering service: {info.name} on {ip_address}:{info.port}")
    zeroconf.register_service(info)

    # 2. Browse for services (will also find our own registered service)
    print("Starting service browser for _http._tcp.local.")
    browser = ServiceBrowser(zeroconf, "_http._tcp.local.", listener=MyListener())

    print("Running for 30 seconds to allow discovery and registration. Press Ctrl+C to stop.")
    time.sleep(30) # Keep running
except KeyboardInterrupt:
    print("Keyboard interrupt received. Shutting down.")
finally:
    if zeroconf:
        print("Unregistering service and closing Zeroconf...")
        if info:
            zeroconf.unregister_service(info)
        zeroconf.close()
    print("Cleanup complete.")