Management framework: broaden get_instances response data to connected instances

This response so far contained only the connected instances that are relevant to
the current configuration, but this isn't very helpful when troubleshooting
instance connectivity. It now reports all currently connected instances, with
network addresses & ports as known to Broker.

scripts/policy/frameworks/management/controller/main.zeek

@@ -93,6 +93,10 @@ global drop_instance: function(inst: Management::Instance);
 global null_config: function(): Management::Configuration;
 global is_null_config: function(config: Management::Configuration): bool;
 
+# Given a Broker ID, this returns the endpoint info associated with it.
+# On error, returns a dummy record with an empty ID string.
+global find_endpoint: function(id: string): Broker::EndpointInfo;
+
 # Checks whether the given instance is one that we know with different
 # communication settings: a different peering direction, a different listening
 # port, etc. Used as a predicate to indicate when we need to drop the existing
@@ -101,19 +105,21 @@ global is_instance_connectivity_change: function(inst: Management::Instance): bo
 
 # The set of agents the controller interacts with to manage the currently
 # configured cluster. This may be a subset of all the agents known to the
-# controller, tracked by the g_instances_known set. They key is the instance
+# controller, tracked by the g_instances_known table. They key is the instance
 # name and should match the $name member of the corresponding instance record.
 global g_instances: table[string] of Management::Instance = table();
 
-# The set of instances that the controller communicates with. This may be a
+# The instances the controller is communicating with. This can deviate from
-# superset of g_instances, since it covers any agent that has sent us a
+# g_instances, since it covers any agent that has sent us a notify_agent_hello
-# notify_agent_hello event.
+# event, regardless of whether it relates to the current configuration.
-global g_instances_known: set[string] = set();
+global g_instances_known: table[string] of Management::Instance = table();
 
-# A corresponding set of instances/agents that we track in order to understand
+# The set of instances we need for the current configuration and that are ready
-# when all of the above instances have sent agent_welcome_response events. (An
+# (meaning they have responded to our agent_welcome_request message). Once they
-# alternative would be to use a record that adds a single state bit for each
+# match g_instances, a Management::Controller::API::notify_agents_ready event
-# instance, and store that above.)
+# signals readiness and triggers config deployment.  (An alternative
+# implementation would be via a record that adds a single state bit for each
+# instance, and store that in g_instances.)
 global g_instances_ready: set[string] = set();
 
 # The request ID of the most recent configuration update that's come in from
@@ -210,6 +216,20 @@ function null_config(): Management::Configuration
 	return Management::Configuration($id="");
 	}
 
+function find_endpoint(id: string): Broker::EndpointInfo
+	{
+	local peers = Broker::peers();
+
+	for ( i in peers )
+		{
+		if ( peers[i]$peer$id == id )
+			return peers[i]$peer;
+		}
+
+	# Return a dummy instance.
+	return Broker::EndpointInfo($id="");
+	}
+
 function is_null_config(config: Management::Configuration): bool
 	{
 	return config$id == "";
@@ -294,8 +314,33 @@ event Management::Agent::API::notify_agent_hello(instance: string, id: string, c
 		return;
 		}
 
-	add g_instances_known[instance];
+	local ei = find_endpoint(id);
-	Management::Log::debug(fmt("instance %s now known to us", instance));
+
+	if ( ei$id == "" )
+		{
+		Management::Log::warning(fmt("notify_agent_hello from %s with unknown Broker ID %s",
+		    instance, id));
+		}
+
+	if ( ! ei?$network )
+		{
+		Management::Log::warning(fmt("notify_agent_hello from %s lacks network state, Broker ID %s",
+		    instance, id));
+		}
+
+	if ( ei$id != "" && ei?$network )
+		{
+		g_instances_known[instance] = Management::Instance(
+		    $name=instance, $host=to_addr(ei$network$address));
+
+		if ( ! connecting )
+			{
+			# We connected to this agent, note down its port.
+			g_instances_known[instance]$listen_port = ei$network$bound_port;
+			}
+
+		Management::Log::debug(fmt("instance %s now known to us", instance));
+		}
 
 	if ( instance in g_instances && instance !in g_instances_ready )
 		{
@@ -551,10 +596,16 @@ event Management::Controller::API::get_instances_request(reqid: string)
 	Management::Log::info(fmt("rx Management::Controller::API::get_instances_request %s", reqid));
 
 	local res = Management::Result($reqid = reqid);
+	local inst_names: vector of string;
 	local insts: vector of Management::Instance;
 
-	for ( i in g_instances )
+	for ( inst in g_instances_known )
-		insts += g_instances[i];
+		inst_names += inst;
+
+	sort(inst_names, strcmp);
+
+	for ( i in inst_names )
+		insts += g_instances_known[inst_names[i]];
 
 	res$data = insts;
 
@@ -863,6 +914,11 @@ event Management::Controller::API::test_timeout_request(reqid: string, with_stat
 		}
 	}
 
+event Broker::peer_added(peer: Broker::EndpointInfo, msg: string)
+	{
+	Management::Log::debug(fmt("broker peer %s added: %s", peer, msg));
+	}
+
 event zeek_init()
 	{
 	# Initialize null config at startup. We will replace it once we have