src/grpc.cc

   1 /**
   2  * collectd - src/grpc.cc
   3  * Copyright (C) 2015 Sebastian Harl
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *   Sebastian Harl <sh at tokkee.org>
  25  **/
  26
  27 #include <grpc++/grpc++.h>
  28 #include <google/protobuf/util/time_util.h>
  29
  30 #include "collectd.grpc.pb.h"
  31
  32 extern "C" {
  33 #include <stdbool.h>
  34 #include <pthread.h>
  35
  36 #include "collectd.h"
  37 #include "common.h"
  38 #include "configfile.h"
  39 #include "plugin.h"
  40
  41 #include "daemon/utils_cache.h"
  42
  43         typedef struct {
  44                 char *addr;
  45                 char *port;
  46         } listener_t;
  47
  48         static listener_t *listeners;
  49         static size_t listeners_num;
  50 }
  51
  52 using collectd::Collectd;
  53
  54 using collectd::DispatchValuesRequest;
  55 using collectd::DispatchValuesReply;
  56 using collectd::ListValuesRequest;
  57 using collectd::ListValuesReply;
  58
  59 using google::protobuf::util::TimeUtil;
  60
  61 /*
  62  * proto conversion
  63  */
  64
  65 static grpc::Status unmarshal_value_list(const collectd::types::ValueList &msg, value_list_t *vl)
  66 {
  67         vl->time = NS_TO_CDTIME_T(TimeUtil::TimestampToNanoseconds(msg.time()));
  68         vl->interval = NS_TO_CDTIME_T(TimeUtil::DurationToNanoseconds(msg.interval()));
  69
  70         std::string s;
  71
  72         s = msg.host();
  73         if (!s.length())
  74                 return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
  75                                 grpc::string("missing host name"));
  76         sstrncpy(vl->host, s.c_str(), sizeof(vl->host));
  77
  78         s = msg.plugin();
  79         if (!s.length())
  80                 return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
  81                                 grpc::string("missing plugin name"));
  82         sstrncpy(vl->plugin, s.c_str(), sizeof(vl->plugin));
  83
  84         s = msg.type();
  85         if (!s.length())
  86                 return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
  87                                 grpc::string("missing type name"));
  88         sstrncpy(vl->type, s.c_str(), sizeof(vl->type));
  89
  90         s = msg.plugin_instance();
  91         sstrncpy(vl->plugin_instance, s.c_str(), sizeof(vl->plugin_instance));
  92
  93         s = msg.type_instance();
  94         sstrncpy(vl->type_instance, s.c_str(), sizeof(vl->type_instance));
  95
  96         value_t *values = NULL;
  97         size_t values_len = 0;
  98         auto status = grpc::Status::OK;
  99
 100         for (auto v : msg.value()) {
 101                 value_t *val = (value_t *)realloc(values, (values_len + 1) * sizeof(*values));
 102                 if (!val) {
 103                         status = grpc::Status(grpc::StatusCode::RESOURCE_EXHAUSTED,
 104                                         grpc::string("failed to allocate values array"));
 105                         break;
 106                 }
 107
 108                 values = val;
 109                 val = values + values_len;
 110                 values_len++;
 111
 112                 switch (v.value_case()) {
 113                 case collectd::types::Value::ValueCase::kCounter:
 114                         val->counter = counter_t(v.counter());
 115                         break;
 116                 case collectd::types::Value::ValueCase::kGauge:
 117                         val->gauge = gauge_t(v.gauge());
 118                         break;
 119                 case collectd::types::Value::ValueCase::kDerive:
 120                         val->derive = derive_t(v.derive());
 121                         break;
 122                 case collectd::types::Value::ValueCase::kAbsolute:
 123                         val->absolute = absolute_t(v.absolute());
 124                         break;
 125                 default:
 126                         status = grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
 127                                         grpc::string("unknown value type"));
 128                         break;
 129                 }
 130
 131                 if (!status.ok())
 132                         break;
 133         }
 134         if (status.ok()) {
 135                 vl->values = values;
 136                 vl->values_len = values_len;
 137         }
 138         else if (values) {
 139                 free(values);
 140         }
 141
 142         return status;
 143 } /* unmarshal_value_list() */
 144
 145 /*
 146  * request call-backs and call objects
 147  */
 148
 149 static grpc::Status Process(grpc::ServerContext *ctx,
 150                 DispatchValuesRequest request, DispatchValuesReply *reply)
 151 {
 152         value_list_t vl = VALUE_LIST_INIT;
 153         auto status = unmarshal_value_list(request.values(), &vl);
 154         if (!status.ok())
 155                 return status;
 156
 157         if (plugin_dispatch_values(&vl))
 158                 status = grpc::Status(grpc::StatusCode::INTERNAL,
 159                                 grpc::string("failed to enqueue values for writing"));
 160         return status;
 161 } /* Process(): DispatchValues */
 162
 163 static grpc::Status Process(grpc::ServerContext *ctx,
 164                 ListValuesRequest request, ListValuesReply *reply)
 165 {
 166         char **names = NULL;
 167         cdtime_t *times = NULL;
 168         size_t i, n = 0;
 169
 170         if (uc_get_names(&names, &times, &n))
 171                 return grpc::Status(grpc::StatusCode::INTERNAL,
 172                                 grpc::string("failed to retrieve values"));
 173
 174         for (i = 0; i < n; i++) {
 175                 auto v = reply->add_value();
 176                 auto t = TimeUtil::NanosecondsToTimestamp(CDTIME_T_TO_NS(times[i]));
 177                 v->set_name(names[i]);
 178                 v->set_allocated_time(new google::protobuf::Timestamp(t));
 179                 sfree(names[i]);
 180         }
 181         sfree(names);
 182         sfree(times);
 183
 184         return grpc::Status::OK;
 185 } /* Process(): ListValues */
 186
 187 class Call
 188 {
 189 public:
 190         Call(Collectd::AsyncService *service, grpc::ServerCompletionQueue *cq)
 191                 : service_(service), cq_(cq), status_(CREATE)
 192         { }
 193
 194         virtual ~Call()
 195         { }
 196
 197         void Handle()
 198         {
 199                 if (status_ == CREATE) {
 200                         Create();
 201                         status_ = PROCESS;
 202                 }
 203                 else if (status_ == PROCESS) {
 204                         Process();
 205                         status_ = FINISH;
 206                 }
 207                 else {
 208                         GPR_ASSERT(status_ == FINISH);
 209                         Finish();
 210                 }
 211         } /* Handle() */
 212
 213 protected:
 214         virtual void Create() = 0;
 215         virtual void Process() = 0;
 216         virtual void Finish() = 0;
 217
 218         Collectd::AsyncService *service_;
 219         grpc::ServerCompletionQueue *cq_;
 220         grpc::ServerContext ctx_;
 221
 222 private:
 223         enum CallStatus { CREATE, PROCESS, FINISH };
 224         CallStatus status_;
 225 }; /* class Call */
 226
 227 template<typename RequestT, typename ReplyT>
 228 class RpcCall final : public Call
 229 {
 230         typedef void (Collectd::AsyncService::*CreatorT)(grpc::ServerContext *,
 231                         RequestT *, grpc::ServerAsyncResponseWriter<ReplyT> *,
 232                         grpc::CompletionQueue *, grpc::ServerCompletionQueue *, void *);
 233
 234 public:
 235         RpcCall(Collectd::AsyncService *service,
 236                         CreatorT creator, grpc::ServerCompletionQueue *cq)
 237                 : Call(service, cq), creator_(creator), responder_(&ctx_)
 238         {
 239                 Handle();
 240         } /* RpcCall() */
 241
 242         virtual ~RpcCall()
 243         { }
 244
 245 private:
 246         void Create()
 247         {
 248                 (service_->*creator_)(&ctx_, &request_, &responder_, cq_, cq_, this);
 249         } /* Create() */
 250
 251         void Process()
 252         {
 253                 // Add a new request object to the queue.
 254                 new RpcCall<RequestT, ReplyT>(service_, creator_, cq_);
 255                 grpc::Status status = ::Process(&ctx_, request_, &reply_);
 256                 responder_.Finish(reply_, status, this);
 257         } /* Process() */
 258
 259         void Finish()
 260         {
 261                 delete this;
 262         } /* Finish() */
 263
 264         CreatorT creator_;
 265
 266         RequestT request_;
 267         ReplyT reply_;
 268
 269         grpc::ServerAsyncResponseWriter<ReplyT> responder_;
 270 }; /* class RpcCall */
 271
 272 /*
 273  * gRPC server implementation
 274  */
 275
 276 class CollectdServer final
 277 {
 278 public:
 279         void Start()
 280         {
 281                 // TODO: make configurable
 282                 auto auth = grpc::InsecureServerCredentials();
 283
 284                 grpc::ServerBuilder builder;
 285
 286                 if (!listeners_num) {
 287                         std::string default_addr("0.0.0.0:50051");
 288                         builder.AddListeningPort(default_addr, auth);
 289                         INFO("grpc: Listening on %s", default_addr.c_str());
 290                 }
 291                 else {
 292                         size_t i;
 293                         for (i = 0; i < listeners_num; i++) {
 294                                 auto l = listeners[i];
 295                                 std::string addr(l.addr);
 296                                 addr += std::string(":") + std::string(l.port);
 297                                 builder.AddListeningPort(addr, auth);
 298                                 INFO("grpc: Listening on %s", addr.c_str());
 299                         }
 300                 }
 301
 302                 builder.RegisterService(&service_);
 303                 cq_ = builder.AddCompletionQueue();
 304                 server_ = builder.BuildAndStart();
 305         } /* Start() */
 306
 307         void Shutdown()
 308         {
 309                 server_->Shutdown();
 310                 cq_->Shutdown();
 311         } /* Shutdown() */
 312
 313         void Mainloop()
 314         {
 315                 // Register request types.
 316                 new RpcCall<DispatchValuesRequest, DispatchValuesReply>(&service_,
 317                                 &Collectd::AsyncService::RequestDispatchValues, cq_.get());
 318                 new RpcCall<ListValuesRequest, ListValuesReply>(&service_,
 319                                 &Collectd::AsyncService::RequestListValues, cq_.get());
 320
 321                 while (true) {
 322                         void *req = NULL;
 323                         bool ok = false;
 324
 325                         if (!cq_->Next(&req, &ok))
 326                                 break; // Queue shut down.
 327                         if (!ok) {
 328                                 ERROR("grpc: Failed to read from queue");
 329                                 break;
 330                         }
 331
 332                         static_cast<Call *>(req)->Handle();
 333                 }
 334         } /* Mainloop() */
 335
 336 private:
 337         Collectd::AsyncService service_;
 338
 339         std::unique_ptr<grpc::Server> server_;
 340         std::unique_ptr<grpc::ServerCompletionQueue> cq_;
 341 }; /* class CollectdServer */
 342
 343 static CollectdServer *server = nullptr;
 344
 345 /*
 346  * collectd plugin interface
 347  */
 348
 349 extern "C" {
 350         static pthread_t *workers;
 351         static size_t workers_num = 5;
 352
 353         static void *worker_thread(void *arg)
 354         {
 355                 CollectdServer *s = (CollectdServer *)arg;
 356                 s->Mainloop();
 357                 return NULL;
 358         } /* worker_thread() */
 359
 360         static int c_grpc_config_listen(oconfig_item_t *ci)
 361         {
 362                 listener_t *listener;
 363                 int i;
 364
 365                 if ((ci->values_num != 2)
 366                                 || (ci->values[0].type != OCONFIG_TYPE_STRING)
 367                                 || (ci->values[1].type != OCONFIG_TYPE_STRING)) {
 368                         ERROR("grpc: The `%s` config option needs exactly "
 369                                         "two string argument (address and port).", ci->key);
 370                         return -1;
 371                 }
 372
 373                 listener = (listener_t *)realloc(listeners,
 374                                 (listeners_num + 1) * sizeof(*listeners));
 375                 if (!listener) {
 376                         ERROR("grpc: Failed to allocate listeners");
 377                         return -1;
 378                 }
 379                 listeners = listener;
 380                 listener = listeners + listeners_num;
 381                 listeners_num++;
 382
 383                 listener->addr = strdup(ci->values[0].value.string);
 384                 listener->port = strdup(ci->values[1].value.string);
 385
 386                 for (i = 0; i < ci->children_num; i++) {
 387                         oconfig_item_t *child = ci->children + i;
 388                         WARNING("grpc: Option `%s` not allowed in <%s> block.",
 389                                         child->key, ci->key);
 390                 }
 391
 392                 return 0;
 393         } /* c_grpc_config_listen() */
 394
 395         static int c_grpc_config(oconfig_item_t *ci)
 396         {
 397                 int i;
 398
 399                 for (i = 0; i < ci->children_num; i++) {
 400                         oconfig_item_t *child = ci->children + i;
 401
 402                         if (!strcasecmp("Listen", child->key)) {
 403                                 if (c_grpc_config_listen(child))
 404                                         return -1;
 405                         }
 406                         else if (!strcasecmp("WorkerThreads", child->key)) {
 407                                 int n;
 408                                 if (cf_util_get_int(child, &n))
 409                                         return -1;
 410                                 workers_num = (size_t)n;
 411                         }
 412                         else {
 413                                 WARNING("grpc: Option `%s` not allowed here.", child->key);
 414                         }
 415                 }
 416
 417                 return 0;
 418         } /* c_grpc_config() */
 419
 420         static int c_grpc_init(void)
 421         {
 422                 server = new CollectdServer();
 423                 size_t i;
 424
 425                 if (! server) {
 426                         ERROR("grpc: Failed to create server");
 427                         return -1;
 428                 }
 429
 430                 workers = (pthread_t *)calloc(workers_num, sizeof(*workers));
 431                 if (! workers) {
 432                         delete server;
 433                         server = nullptr;
 434
 435                         ERROR("grpc: Failed to allocate worker threads");
 436                         return -1;
 437                 }
 438
 439                 server->Start();
 440                 for (i = 0; i < workers_num; i++) {
 441                         pthread_create(&workers[i], /* attr = */ NULL,
 442                                         worker_thread, server);
 443                 }
 444                 INFO("grpc: Started %zu workers", workers_num);
 445                 return 0;
 446         } /* c_grpc_init() */
 447
 448         static int c_grpc_shutdown(void)
 449         {
 450                 size_t i;
 451
 452                 if (!server)
 453                         return -1;
 454
 455                 server->Shutdown();
 456
 457                 INFO("grpc: Waiting for %zu workers to terminate", workers_num);
 458                 for (i = 0; i < workers_num; i++)
 459                         pthread_join(workers[i], NULL);
 460                 free(workers);
 461                 workers = NULL;
 462                 workers_num = 0;
 463
 464                 delete server;
 465                 server = nullptr;
 466
 467                 return 0;
 468         } /* c_grpc_shutdown() */
 469
 470         void module_register(void)
 471         {
 472                 plugin_register_complex_config("grpc", c_grpc_config);
 473                 plugin_register_init("grpc", c_grpc_init);
 474                 plugin_register_shutdown("grpc", c_grpc_shutdown);
 475         } /* module_register() */
 476 } /* extern "C" */
 477
 478 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */