2 problems:
i've built and install grpc with guide https://github.com/grpc/grpc/blob/master/BUILDING.md, grpc tag is v1.41.0. but i can't find resolver.h nor balancer.h in /usr/local/include/grpc++/, but in grpc source code its in grpc/src/core/lib/resolver/
how to convert endpoint string to somekind grpc result struct, and Set the result into grpc? cant find an example
here is my code:
#pragma once
#include <grpc/grpc.h>
#include <grpcpp/grpcpp.h>
#include <grpcpp/client_context.h>
#include <grpcpp/create_channel.h>
#include <grpcpp/support/channel_arguments.h>
#include <thread>
#include <mutex>
#include <condition_variable>
#include <vector>
#include "etcd-cpp-apiv3/Client.hpp"
#include "etcd-cpp-apiv3/Response.hpp"
#include "etcd-cpp-apiv3/Watcher.hpp"
class EtcdResolver : public grpc_core::Resolver {
public:
explicit EtcdResolver(const std::string& etcd_address, const std::string& service_name,
const std::string& runtime, const std::string& ca, const std::string& cert, const std::string& prikey)
{
etcd::Client* etcd = etcd::Client::WithSSL(etcd_address, ca, cert, prikey);
if (etcd == nullptr)
{
printf("create xetcd client fail\n");
exit(1);
}
std::shared_ptr<etcd::Client> shared_client(etcd);
client_ = shared_client;
runtime_ = runtime;
etcd_address_ = etcd_address;
service_name_ = service_name;
ca_ = ca;
cert_ = cert;
prikey_ = prikey;
};
~EtcdResolver(){};
void StartLocked()
{
std::vector<std::string> endpoints = FirstGetEndpointsFromEtcd();
grpc::ChannelArguments args;
args.SetServiceConfigJSON("{\"loadBalancingConfig\":[{\"round_robin\":{}}]}");
for (const auto& endpoint : endpoints) {
// how to convert string to grpc_core::Resolver::Result ?
}
UpdateStateLocked(result_);
etcd::Watcher watcher(*client_.get(), service_key_, std::bind(&EtcdResolver::OnWatch, this, std::placeholders::_1), true);
std::shared_ptr<etcd::Watcher> shared_watcher(&watcher);
watcher_ = shared_watcher;
};
void RequestReresolution(){};
void ResetBackoff(){};
void UpdateStateLocked(grpc_core::Resolver::Result result)
{
// how to set the result into grpc?
};
private:
std::vector<std::string> FirstGetEndpointsFromEtcd()
{
std::vector<std::string> endpoints;
service_key_ = std::string("services_prefix/") + runtime_ + "/" + service_name_ + "/";
auto resp = client_->ls(service_key_).get();
if (resp.error_code() != 0) {
throw std::runtime_error(resp.error_message());
}
for (const auto& val : resp.values()) {
Json::Reader reader;
Json::Value value;
if (reader.parse(val.as_string(), value)){
endpoints.emplace_back(value["addr"].asString());
}
}
return endpoints;
};
void OnWatch(etcd::Response const & resp)
{
if (!resp.is_ok()) return;
std::cout << "OnWatch triggered" << std::endl;
auto resp2 = client_->ls(service_key_).get();
if (resp2.error_code() != 0) {
throw std::runtime_error(resp2.error_message());
}
std::unique_lock<std::mutex> lock(mutex_);
std::vector<std::string> endpoints;
for (const auto& val : resp2.values()) {
Json::Reader reader;
Json::Value value;
if (reader.parse(val.as_string(), value)){
endpoints.emplace_back(value["addr"].asString());
}
}
for (const auto& endpoint : endpoints) {
// how to convert string to grpc_core::Resolver::Result ?
}
std::unique_lock<std::mutex> unlock(mutex_);
UpdateStateLocked(result_);
};
private:
std::string runtime_;
std::string etcd_address_;
std::string service_name_;
std::shared_ptr<etcd::Client> client_;
std::shared_ptr<etcd::Watcher> watcher_;
grpc_core::Resolver::Result result_;
std::mutex mutex_;
std::string ca_;
std::string cert_;
std::string prikey_;
std::string service_key_;
};
i tried reading grpc src code and found below, and cant make sure its right?
// convert string to grpc_core::Resolver::Result
grpc_resolved_address resolved_address;
memset(&resolved_address, 0, sizeof(grpc_resolved_address));
absl::StatusOr<grpc_core::URI> uri = grpc_core::URI::Parse(endpoint);
grpc_parse_uri(uri, &resolved_address);
result_.addresses.emplace_back(grpc_core::ServerAddress(resolved_address, nullptr));
and still cant find a way to set the Result into grpc inside
