Implement minimal supervised cluster configuration

More aspects of the cluster configuration to get fleshed out later,
but a basic cluster like one would use for a live deployment
can now be instantiated and run under supervision.  The new
clusterized-pcap-processing supervisor mode is also not done yet.

scripts/base/frameworks/cluster/__load__.zeek

@@ -18,7 +18,12 @@ redef Broker::log_topic = Cluster::rr_log_topic;
 # Loading the cluster framework requires that a script by this name exists
 # somewhere in the ZEEKPATH.  The only thing in the file should be the
 # cluster definition in the :zeek:id:`Cluster::nodes` variable.
+
+@if ( ! Supervisor::__init_cluster() )
+# When running a supervised cluster, Cluster::nodes is instead populated
+# from the internal C++-layer directly via the above BIF.
 @load cluster-layout
+@endif
 
 @if ( Cluster::node in Cluster::nodes )
 

scripts/base/frameworks/cluster/main.zeek

@@ -287,7 +287,13 @@ function is_enabled(): bool
 
 function local_node_type(): NodeType
 	{
-	return is_enabled() ? nodes[node]$node_type : NONE;
+	if ( ! is_enabled() )
+		return NONE;
+
+	if ( node !in nodes )
+		return NONE;
+
+	return nodes[node]$node_type;
 	}
 
 function node_topic(name: string): string

scripts/base/frameworks/supervisor/api.zeek

@@ -4,14 +4,32 @@
 module Supervisor;
 
 export {
+	type ClusterRole: enum {
+		NONE,
+		LOGGER,
+		MANAGER,
+		PROXY,
+		WORKER,
+	};
+
+	type ClusterEndpoint: record {
+		role: ClusterRole;
+		host: addr;
+		p: port;
+		interface: string &optional;
+	};
+
 	type Node: record {
-		# TODO: add proper config fields
 		name: string;
+		interface: string &optional;
+		cluster: table[string] of ClusterEndpoint &default=table();
+
+		# TODO: separate node config fields from status fields ?
+		# TODO: add more status fields ?
 		pid: count &optional;
 	};
 
 	type Status: record {
-		# TODO: add more status fields ?
 		nodes: table[string] of Node;
 	};
 

scripts/base/frameworks/supervisor/main.zeek

@@ -54,17 +54,17 @@ function Supervisor::status(nodes: string): Status
 	return Supervisor::__status(nodes);
 	}
 
-function create(node: Node): string
+function Supervisor::create(node: Node): string
 	{
 	return Supervisor::__create(node);
 	}
 
-function destroy(nodes: string): bool
+function Supervisor::destroy(nodes: string): bool
 	{
 	return Supervisor::__destroy(nodes);
 	}
 
-function restart(nodes: string): bool
+function Supervisor::restart(nodes: string): bool
 	{
 	return Supervisor::__restart(nodes);
 	}