plugin: Gate the plugin subsystem with the --enable-plugins configure flag

Since we are planning to release a bug fix release, and the plugin
subsystem is not yet complete, it is better to make plugin support
opt-in while we continue testing.

Signed-off-by: Christian Decker <decker.christian@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

CHANGELOG.md

@@ -14,7 +14,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - JSON API: use `\n\n` to terminate responses, for simplified parsing (pylightning now relies on this)
 - JSON API: `fundchannel` now includes an `announce` option, when false it will keep channel private. Defaults to true.
 - JSON API: `listpeers`'s `channels` now includes a `private` flag to indicate if channel is announced or not.
-- Plugins: Added plugins to `lightningd`, including option passthrough and JSON-RPC passthrough.
+- Plugins: experimental plugin support for `lightningd`, including option passthrough and JSON-RPC passthrough.
 
 ### Changed
 

configure

@@ -10,6 +10,7 @@ CWARNFLAGS=${CWARNFLAGS:--Werror -Wall -Wundef -Wmissing-prototypes -Wmissing-de
 CDEBUGFLAGS=${CDEBUGFLAGS:--std=gnu11 -g -fstack-protector}
 DEVELOPER=${DEVELOPER:-0}
 EXPERIMENTAL_FEATURES=${EXPERIMENTAL_FEATURES:-0}
+PLUGINS=${PLUGINS:-0}
 COMPAT=${COMPAT:-1}
 STATIC=${STATIC:-0}
 CONFIGURATOR_CC=${CONFIGURATOR_CC:-$CC}
@@ -55,6 +56,10 @@ usage()
     echo "    Compatibility mode, good to disable to see if your software breaks"
     usage_with_default "--enable/disable-valgrind" "(autodetect)"
     echo "    Valgrind binary to use for tests"
+    usage_with_default "--enable/disable-experimental-features" "disable"
+    echo "    Experimental features (not for network use!)"
+    usage_with_default "--enable/disable-plugins" "disable"
+    echo "    Support for plugins"
     usage_with_default "--enable/disable-static" "$STATIC" "enable" "disable" 
     echo "    Static link binary"
     exit 1
@@ -113,6 +118,8 @@ for opt in "$@"; do
 	--disable-developer) DEVELOPER=0;;
 	--enable-experimental-features) EXPERIMENTAL_FEATURES=1;;
 	--disable-experimental-features) EXPERIMENTAL_FEATURES=0;;
+	--enable-plugins) PLUGINS=1;;
+	--disable-plugins) PLUGINS=0;;
 	--enable-compat) COMPAT=1;;
 	--disable-compat) COMPAT=0;;
 	--enable-valgrind) VALGRIND=1;;
@@ -151,6 +158,7 @@ add_var CDEBUGFLAGS "$CDEBUGFLAGS"
 add_var VALGRIND "$VALGRIND"
 add_var DEVELOPER "$DEVELOPER" $CONFIG_HEADER
 add_var EXPERIMENTAL_FEATURES "$EXPERIMENTAL_FEATURES" $CONFIG_HEADER
+add_var PLUGINS "$PLUGINS" $CONFIG_HEADER
 add_var COMPAT "$COMPAT" $CONFIG_HEADER
 add_var PYTEST "$PYTEST"
 add_var STATIC "$STATIC"

doc/plugins.md

@@ -16,8 +16,7 @@ variety of ways:
    internal events in `lightningd` and alter its behavior or inject
    custom behaviors.
    
-*Notice: at the time of writing only command line option passthrough
-is implemented, the other features are under active development.*
+*Notice: you need to pass `--enable-plugins` to `./configure` to turn on plugins for now, and hooks are not yet implemented.  The API is under active development.*
 
 A plugin may be written in any language, and communicates with
 `lightningd` through the plugin's `stdin` and `stdout`. JSON-RPCv2 is

lightningd/lightningd.c

@@ -215,8 +215,9 @@ static struct lightningd *new_lightningd(const tal_t *ctx)
 	 *code. Here we initialize the context that will keep track and control
 	 *the plugins.
 	 */
+#ifdef PLUGINS
 	ld->plugins = plugins_new(ld, ld->log_book, ld->jsonrpc, ld);
-
+#endif
 	return ld;
 }
 
@@ -361,10 +362,11 @@ static const char *find_my_pkglibexec_path(struct lightningd *ld,
 
 	/*~ The plugin dir is in ../libexec/c-lightning/plugins, which (unlike
 	 * those given on the command line) does not need to exist. */
+#ifdef PLUGINS
 	add_plugin_dir(ld->plugins,
 		       path_join(tmpctx, pkglibexecdir, "plugins"),
 		       true);
-
+#endif
 	/*~ Sometimes take() can be more efficient, since the routine can
 	 * manipulate the string in place.  This is the case here. */
 	return path_simplify(ld, take(pkglibexecdir));
@@ -377,9 +379,11 @@ static const char *find_daemon_dir(struct lightningd *ld, const char *argv0)
 	/* If we're running in-tree, all the subdaemons are with lightningd. */
 	if (has_all_subdaemons(my_path)) {
 		/* In this case, look in ../plugins */
+#ifdef PLUGINS
 		add_plugin_dir(ld->plugins,
 			       path_join(tmpctx, my_path, "../plugins"),
 			       true);
+#endif
 		return my_path;
 	}
 
@@ -661,8 +665,9 @@ int main(int argc, char *argv[])
 	/*~ Initialize all the plugins we just registered, so they can
 	 *  do their thing and tell us about themselves (including
 	 *  options registration). */
+#ifdef PLUGINS
 	plugins_init(ld->plugins, ld->dev_debug_subprocess);
-
+#endif
 	/*~ Handle options and config; move to .lightningd (--lightning-dir) */
 	handle_opts(ld, argc, argv);
 
@@ -762,8 +767,9 @@ int main(int argc, char *argv[])
 
 	/*~ Now that the rpc path exists, we can start the plugins and they
 	 * can start talking to us. */
+#ifdef PLUGINS
 	plugins_config(ld->plugins);
-
+#endif
 	/*~ We defer --daemon until we've completed most initialization: that
 	 *  way we'll exit with an error rather than silently exiting 0, then
 	 *  realizing we can't start and forcing the confused user to read the

lightningd/lightningd.h

@@ -205,8 +205,9 @@ struct lightningd {
 	bool use_proxy_always;
 	char *tor_service_password;
 	bool pure_tor_setup;
-
+#ifdef PLUGINS
 	struct plugins *plugins;
+#endif
 };
 
 const struct chainparams *get_chainparams(const struct lightningd *ld);

lightningd/options.c

@@ -318,6 +318,7 @@ static void config_register_opts(struct lightningd *ld)
 		&ld->config_filename,
 		"Specify configuration file. Relative paths will be prefixed by lightning-dir location. (default: config)");
 
+#ifdef PLUGINS
 	/* Register plugins as an early args, so we can initialize them and have
 	 * them register more command line options */
 	opt_register_early_arg("--plugin", opt_add_plugin, NULL, ld,
@@ -331,7 +332,7 @@ static void config_register_opts(struct lightningd *ld)
 	opt_register_early_arg("--disable-plugin", opt_disable_plugin,
 			       NULL, ld,
 			       "Disable a particular plugin by filename/name");
-
+#endif
 	opt_register_noarg("--daemon", opt_set_bool, &ld->daemon,
 			 "Run in the background, suppress stdout/stderr");
 	opt_register_arg("--ignore-fee-limits", opt_set_bool_arg, opt_show_bool,

tests/fixtures.py

@@ -17,7 +17,6 @@ VALGRIND = os.getenv("VALGRIND", config['VALGRIND']) == "1"
 DEVELOPER = os.getenv("DEVELOPER", config['DEVELOPER']) == "1"
 TEST_DEBUG = os.getenv("TEST_DEBUG", "0") == "1"
 
-
 if TEST_DEBUG:
     logging.basicConfig(level=logging.DEBUG, stream=sys.stdout)
 

tests/test_plugin.py

@@ -1,11 +1,14 @@
 from collections import OrderedDict
 from fixtures import *  # noqa: F401,F403
 from lightning import RpcError
+from utils import PLUGINS
 
 import pytest
 import subprocess
+import unittest
 
 
+@unittest.skipIf(not PLUGINS, "plugin subsystem requires PLUGINS flag")
 def test_option_passthrough(node_factory):
     """ Ensure that registering options works.
 
@@ -32,6 +35,7 @@ def test_option_passthrough(node_factory):
     n.stop()
 
 
+@unittest.skipIf(not PLUGINS, "plugin subsystem requires PLUGINS flag")
 def test_rpc_passthrough(node_factory):
     """Starting with a plugin exposes its RPC methods.
 
@@ -58,12 +62,14 @@ def test_rpc_passthrough(node_factory):
         n.rpc.fail()
 
 
+@unittest.skipIf(not PLUGINS, "plugin subsystem requires PLUGINS flag")
 def test_plugin_dir(node_factory):
     """--plugin-dir works"""
     plugin_dir = 'contrib/plugins'
     node_factory.get_node(options={'plugin-dir': plugin_dir, 'greeting': 'Mars'})
 
 
+@unittest.skipIf(not PLUGINS, "plugin subsystem requires PLUGINS flag")
 def test_plugin_disable(node_factory):
     """--disable-plugin works"""
     plugin_dir = 'contrib/plugins'
@@ -83,6 +89,7 @@ def test_plugin_disable(node_factory):
         n.rpc.hello(name='Sun')
 
 
+@unittest.skipIf(not PLUGINS, "plugin subsystem requires PLUGINS flag")
 def test_plugin_notifications(node_factory):
     l1, l2 = node_factory.get_nodes(2, opts={'plugin': 'contrib/plugins/helloworld.py'})
 
@@ -95,6 +102,7 @@ def test_plugin_notifications(node_factory):
     l2.daemon.wait_for_log(r'Received disconnect event')
 
 
+@unittest.skipIf(not PLUGINS, "plugin subsystem requires PLUGINS flag")
 def test_failing_plugins():
     fail_plugins = [
         'contrib/plugins/fail/failtimeout.py',

tests/utils.py

@@ -41,6 +41,7 @@ EXPERIMENTAL_FEATURES = os.getenv("EXPERIMENTAL_FEATURES", config['EXPERIMENTAL_
 TIMEOUT = int(os.getenv("TIMEOUT", "60"))
 VALGRIND = os.getenv("VALGRIND", config['VALGRIND']) == "1"
 SLOW_MACHINE = os.getenv("SLOW_MACHINE", "0") == "1"
+PLUGINS = os.getenv("PLUGINS", config['PLUGINS']) == "1"
 
 
 def wait_for(success, timeout=TIMEOUT):