A C++11 wrapper to build plugins for C-lightning and access its JSON-RPC interface
This library makes an extensive use of libjson-rpc-cpp. Recommended way is to build it from source (here are Debian instructions but you can find more here) :
apt install libcurl4 libmicrohttpd-dev libjsoncpp-dev libargtable2-dev cmake libhiredis-dev catch libcurl4-openssl-dev
git clone git://github.com/cinemast/libjson-rpc-cpp.git
mkdir -p libjson-rpc-cpp/build
cd libjson-rpc-cpp/build
cmake -DUNIX_DOMAIN_SOCKET_CLIENT=YES .. && make -j8
make install # as root
ldconfig # as rootThen you can install lightningcpp :
git clone git@github.com:darosior/lightningcpp.git
cd lightningcpp
make
su -c "make install"#include <clightningrpc.h>
#include <iostream>
#include <string>
int main (int argc, char *argv[])
{
CLightningWrapper lightning = CLightningWrapper("/home/darosior/.lightning/lightning-rpc");
std::cout << lightning.getInfo() << std::endl;
return 0;
}You can write a plugin by whether inheriting the RpcMethod class :
#include <clightningplugin.h>
class Helloworld: public RpcMethod {
public:
Helloworld(): RpcMethod() {
name = "hello";
description = "launch me so that I can greet the world";
}
Json::Value main(Json::Value ¶ms) {
return Json::Value("Hello world !");
}
};
int main(int argc, char *argv[]) {
Plugin testPlugin;
Helloworld helloworld;
testPlugin.addMethod(helloworld);
testPlugin.start();
return 0;
}Or you can instanciate an RpcMethod object and set the main function :
#include <clightningplugin.h>
#include <string>
int main(int argc, char *argv[]) {
Plugin testPlugin;
RpcMethod byeworld("bye", "[name]", "Launch me so I can say bye to someone", "I am a long description");
byeworld.setMain([&](Json::Value ¶ms) {
std::string bye = "Bye bye ";
if (!params.empty())
return Json::Value(bye + params.asString());
return Json::Value(bye + "world !");
});
testPlugin.addMethod(byeworld);
testPlugin.start();
return 0;
}You can add startup options, for example with the byebye plugin from above :
#include <clightningplugin.h>
#include <string>
int main(int argc, char *argv[]) {
Plugin testPlugin;
testPlugin.addOption("byename", "world", "who to say bye to");
RpcMethod byeworld("bye", "[name]", "Launch me so I can say bye to someone", "A LONG DESC");
byeworld.setMain([&](Json::Value ¶ms) {
std::string bye = "Bye bye ";
if (params.size() == 1)
return Json::Value(bye + params[0].asString() + " !");
return Json::Value(bye + testPlugin.getOptionValue("byename").asString() + " !");
});
testPlugin.addMethod(byeworld);
testPlugin.start();
return 0;
}You can use addOption() by whether passing it a Json::Value, or the option
name, default value, description, and type (which defaults to string and is
not passed in the above example).
You can subscribe to lightningd's notifications :
#include <clightningplugin.h>
#include <fstream>
class Helloworld: public RpcMethod {
public:
Helloworld(): RpcMethod() {
name = "hello";
description = "launch me so that I can greet the world";
}
Json::Value main(Json::Value ¶ms) {
return Json::Value("Hello world !");
}
};
void uselessLogger(Json::Value ¶ms) {
std::ofstream logFile;
logFile.open("log_file.log", std::ios::app);
std::string what = params["warning"]["log"].asString();
logFile << what << std::endl;
logFile.close();
}
int main(int argc, char *argv[]) {
Plugin testPlugin;
Helloworld helloworld;
testPlugin.addMethod(helloworld);
testPlugin.subscribe("warning", &uselessLogger);
testPlugin.start();
return 0;
}You can subscribe to lightningd's
hooks (but be sure
of what you are doing) :
#include <clightningplugin.h>
#include <fstream>
class Helloworld: public RpcMethod {
public:
Helloworld(): RpcMethod() {
name = "hello";
description = "launch me so that I can greet the world";
}
Json::Value main(Json::Value ¶ms) {
return Json::Value("Hello world !");
}
};
Json::Value dbDump(Json::Value ¶ms) {
std::ofstream logFile;
logFile.open("db.log", std::ios::app);
std::string operation = params["writes"][0].asString();
logFile << operation << std::endl;
logFile.close();
return Json::Value(true);
}
int main(int argc, char *argv[]) {
Plugin testPlugin;
Helloworld helloworld;
testPlugin.addMethod(helloworld);
testPlugin.hookSubscribe("db_write", &dbDump);
testPlugin.start();
return 0;
}Highly inspired by Christian Decker's pylightning.
The RPC wrapper is just a class (CLightningRpc) with methods wrapping lightningd's API.
There are 2 classes for the Plugin management : Plugin and RpcMethod. Every RPC method added to lightningd must be an instance of
RpcMethod, which is composed of a method's attributes (namely the name, usage, description and long description) and a pointer to the
function to be executed when the method is called through lightningd.
This pointer defaults to the main(Json::Value&) function of the same class.
Any method's main function must take a Json::Value object as parameter and return a Json::Value.
You can assign it after instanciation with the setMain() method (as per examples above).
You can find more about C-lightning plugins :
- On the lightningd/plugins repo
- On the doc
- On the C-lightning repo
Plugins in other languages :
BSD 3-clause clear