lightningd/plugin: Add a 'dynamic' field to getmanifest and a 'startup' field to init

This lets a plugin specify whether it can be restarted, and to know if it is started at lightningd startup

contrib/pylightning/lightning/plugin.py

@@ -99,7 +99,7 @@ class Plugin(object):
 
     """
 
-    def __init__(self, stdout=None, stdin=None, autopatch=True):
+    def __init__(self, stdout=None, stdin=None, autopatch=True, dynamic=True):
         self.methods = {'init': Method('init', self._init, MethodType.RPCMETHOD)}
         self.options = {}
 
@@ -118,6 +118,8 @@ class Plugin(object):
         self.rpc_filename = None
         self.lightning_dir = None
         self.rpc = None
+        self.startup = True
+        self.dynamic = dynamic
         self.child_init = None
 
         self.write_lock = RLock()
@@ -496,6 +498,7 @@ class Plugin(object):
             'rpcmethods': methods,
             'subscriptions': list(self.subscriptions.keys()),
             'hooks': hooks,
+            'dynamic': self.dynamic
         }
 
     def _init(self, options, configuration, request):
@@ -503,6 +506,7 @@ class Plugin(object):
         self.lightning_dir = configuration['lightning-dir']
         path = os.path.join(self.lightning_dir, self.rpc_filename)
         self.rpc = LightningRpc(path)
+        self.startup = configuration['startup']
         for name, value in options.items():
             self.options[name]['value'] = value
 

lightningd/plugin.c

@@ -789,7 +789,8 @@ static void plugin_manifest_cb(const char *buffer,
 			       const jsmntok_t *idtok,
 			       struct plugin *plugin)
 {
-	const jsmntok_t *resulttok;
+	const jsmntok_t *resulttok, *dynamictok;
+	bool dynamic_plugin;
 
 	/* Check if all plugins have replied to getmanifest, and break
 	 * if they have and this is the startup init */
@@ -806,6 +807,10 @@ static void plugin_manifest_cb(const char *buffer,
 		return;
 	}
 
+	dynamictok = json_get_member(buffer, resulttok, "dynamic");
+	if (dynamictok && json_to_bool(buffer, dynamictok, &dynamic_plugin))
+		plugin->dynamic = dynamic_plugin;
+
 	if (!plugin_opts_add(plugin, buffer, resulttok) ||
 	    !plugin_rpcmethods_add(plugin, buffer, resulttok) ||
 	    !plugin_subscriptions_add(plugin, buffer, resulttok) ||
@@ -1014,6 +1019,7 @@ static void plugin_config(struct plugin *plugin)
 	json_object_start(req->stream, "configuration");
 	json_add_string(req->stream, "lightning-dir", ld->config_dir);
 	json_add_string(req->stream, "rpc-file", ld->rpc_filename);
+	json_add_bool(req->stream, "startup", plugin->plugins->startup);
 	json_object_end(req->stream);
 
 	jsonrpc_request_end(req);

lightningd/plugin.h

@@ -21,6 +21,8 @@ struct plugin {
 	struct plugins *plugins;
 	const char **plugin_path;
 	bool configured;
+	/* If this plugin can be restarted without restarting lightningd */
+	bool dynamic;
 
 	/* Stuff we read */
 	char *buffer;