Add option to change supervised node's working directory

scripts/base/frameworks/supervisor/api.zeek

@@ -22,6 +22,7 @@ export {
 	type Node: record {
 		name: string;
 		interface: string &optional;
+		directory: string &optional;
 		cluster: table[string] of ClusterEndpoint &default=table();
 
 		# TODO: separate node config fields from status fields ?

src/Supervisor.cc

@@ -2,7 +2,7 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
-#include <signal.h>
+#include <csignal>
 #include <fcntl.h>
 #include <poll.h>
 
@@ -720,6 +720,11 @@ Supervisor::Node Supervisor::Node::FromRecord(const RecordVal* node)
 	if ( iface_val )
 		rval.interface = iface_val->AsString()->CheckString();
 
+	auto directory_val = node->Lookup("directory");
+
+	if ( directory_val )
+		rval.directory = directory_val->AsString()->CheckString();
+
 	auto cluster_table_val = node->Lookup("cluster")->AsTableVal();
 	auto cluster_table = cluster_table_val->AsTable();
 	auto c = cluster_table->InitForIteration();
@@ -754,11 +759,12 @@ Supervisor::Node Supervisor::Node::FromJSON(const std::string& json)
 	auto j = nlohmann::json::parse(json);
 	rval.name = j["name"];
 
-	auto it = j.find("interface");
-
-	if ( it != j.end() )
+	if ( auto it = j.find("interface"); it != j.end() )
 		rval.interface = *it;
 
+	if ( auto it = j.find("directory"); it != j.end() )
+		rval.directory= *it;
+
 	auto cluster = j["cluster"];
 
 	for ( const auto& e : cluster.items() )
@@ -803,6 +809,9 @@ IntrusivePtr<RecordVal> Supervisor::Node::ToRecord() const
 	if ( interface )
 		rval->Assign(rt->FieldOffset("interface"), new StringVal(*interface));
 
+	if ( directory )
+		rval->Assign(rt->FieldOffset("directory"), new StringVal(*directory));
+
 	auto tt = BifType::Record::Supervisor::Node->FieldType("cluster");
 	auto cluster_val = new TableVal(tt->AsTableType());
 	rval->Assign(rt->FieldOffset("cluster"), cluster_val);
@@ -926,6 +935,15 @@ std::string Supervisor::Create(const Supervisor::Node& node)
 	if ( nodes.find(node.name) != nodes.end() )
 		return fmt("node with name '%s' already exists", node.name.data());
 
+	if ( node.directory )
+		{
+		auto res = ensure_intermediate_dirs(node.directory->data());
+
+		if ( ! res )
+			return fmt("failed to create working directory %s\n",
+			           node.directory->data());
+		}
+
 	auto msg = make_create_message(node);
 	safe_write(stem_pipe->OutFD(), msg.data(), msg.size() + 1);
 	nodes.emplace(node.name, node);

src/Supervisor.h

@@ -45,6 +45,7 @@ public:
 
 		std::string name;
 		std::optional<std::string> interface;
+		std::optional<std::string> directory;
 		std::map<std::string, ClusterEndpoint> cluster;
 
 		pid_t pid = 0;

src/main.cc

@@ -800,6 +800,18 @@ int main(int argc, char** argv)
 				exit(1);
 				}
 			}
+
+		if ( zeek::supervised_node->directory )
+			{
+			if ( chdir(zeek::supervised_node->directory->data()) )
+				{
+				fprintf(stderr, "supervised node %s failed to chdir to %s: %s\n",
+				        node_name.data(),
+				        zeek::supervised_node->directory->data(),
+				        strerror(errno));
+				exit(1);
+				}
+			}
 		}
 
 	std::set_new_handler(bro_new_handler);