Zeroconf reports system properties (#59)

* Zeroconf.found_clients() now returns dicts of clients, not just hostnames

* Adjustments to distributed_job_manager.py

* Undo config change

* Report system metrics (cpu, os, etc) via zeroconf_server.py

* Zeroconf.found_clients() now returns dicts of clients, not just hostnames

* Adjustments to distributed_job_manager.py

* Undo config change

* Zeroconf.found_clients() now returns dicts of clients, not just hostnames

* Adjustments to distributed_job_manager.py

* Undo config change

* Adjustments to distributed_job_manager.py

* Undo config change

* Rename ZeroconfServer.found_clients() to found_hostnames()

src/utilities/zeroconf_server.py

@@ -1,6 +1,7 @@
 import logging
 import socket
 
+import zeroconf
 from zeroconf import Zeroconf, ServiceInfo, ServiceBrowser, ServiceStateChange
 
 logger = logging.getLogger()
@@ -24,6 +25,8 @@ class ZeroconfServer:
 
     @classmethod
     def start(cls, listen_only=False):
+        if not cls.service_type:
+            raise RuntimeError("The 'configure' method must be run before starting the zeroconf server")
         if not listen_only:
             cls._register_service()
         cls._browse_services()
@@ -49,8 +52,8 @@ class ZeroconfServer:
             cls.service_info = info
             cls.zeroconf.register_service(info)
             logger.info(f"Registered zeroconf service: {cls.service_info.name}")
-        except socket.gaierror as e:
-            logger.error(f"Error starting zeroconf service: {e}")
+        except zeroconf.NonUniqueNameException as e:
+            logger.error(f"Error establishing zeroconf: {e}")
 
     @classmethod
     def _unregister_service(cls):
@@ -75,19 +78,24 @@ class ZeroconfServer:
                 cls.client_cache.pop(name)
 
     @classmethod
-    def found_clients(cls):
-
+    def found_hostnames(cls):
         fetched_hostnames = [x.split(f'.{cls.service_type}')[0] for x in cls.client_cache.keys()]
         local_hostname = socket.gethostname()
         # Define a sort key function
         def sort_key(hostname):
             # Return 0 if it's the local hostname so it comes first, else return 1
-            return 0 if hostname == local_hostname else 1
+            return False if hostname == local_hostname else True
 
         # Sort the list with the local hostname first
         sorted_hostnames = sorted(fetched_hostnames, key=sort_key)
         return sorted_hostnames
 
+    @classmethod
+    def get_hostname_properties(cls, hostname):
+        new_key = hostname + '.' + cls.service_type
+        server_info = cls.client_cache.get(new_key).properties
+        decoded_server_info = {key.decode('utf-8'): value.decode('utf-8') for key, value in server_info.items()}
+        return decoded_server_info
 
 # Example usage:
 if __name__ == "__main__":