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         typedef struct {
  42                 char *addr;
  43                 char *port;
  44         } listener_t;
  45
  46         static listener_t *listeners;
  47         static size_t listeners_num;
  48 }
  49
  50 using google::protobuf::util::TimeUtil;
  51
  52 /*
  53  * proto conversion
  54  */
  55
  56 static grpc::Status unmarshal_value_list(const collectd::types::ValueList &msg, value_list_t *vl)
  57 {
  58         vl->time = NS_TO_CDTIME_T(TimeUtil::TimestampToNanoseconds(msg.time()));
  59         vl->interval = NS_TO_CDTIME_T(TimeUtil::DurationToNanoseconds(msg.interval()));
  60
  61         std::string s;
  62
  63         s = msg.host();
  64         if (!s.length())
  65                 return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
  66                                 grpc::string("missing host name"));
  67         sstrncpy(vl->host, s.c_str(), sizeof(vl->host));
  68
  69         s = msg.plugin();
  70         if (!s.length())
  71                 return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
  72                                 grpc::string("missing plugin name"));
  73         sstrncpy(vl->plugin, s.c_str(), sizeof(vl->plugin));
  74
  75         s = msg.type();
  76         if (!s.length())
  77                 return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
  78                                 grpc::string("missing type name"));
  79         sstrncpy(vl->type, s.c_str(), sizeof(vl->type));
  80
  81         s = msg.plugin_instance();
  82         if (s.length())
  83                 sstrncpy(vl->plugin_instance, s.c_str(), sizeof(vl->plugin_instance));
  84
  85         s = msg.type_instance();
  86         if (s.length())
  87                 sstrncpy(vl->type_instance, s.c_str(), sizeof(vl->type_instance));
  88
  89         value_t *values = NULL;
  90         size_t values_len = 0;
  91         auto status = grpc::Status::OK;
  92
  93         for (auto v : msg.value()) {
  94                 value_t *val = (value_t *)realloc(values, (values_len + 1) * sizeof(*values));
  95                 if (!val) {
  96                         status = grpc::Status(grpc::StatusCode::RESOURCE_EXHAUSTED,
  97                                         grpc::string("failed to allocate values array"));
  98                         break;
  99                 }
 100
 101                 values = val;
 102                 val = values + values_len;
 103                 values_len++;
 104
 105                 switch (v.value_case()) {
 106                 case collectd::types::Value::ValueCase::kCounter:
 107                         val->counter = counter_t(v.counter());
 108                         break;
 109                 case collectd::types::Value::ValueCase::kGauge:
 110                         val->gauge = gauge_t(v.gauge());
 111                         break;
 112                 case collectd::types::Value::ValueCase::kDerive:
 113                         val->derive = derive_t(v.derive());
 114                         break;
 115                 case collectd::types::Value::ValueCase::kAbsolute:
 116                         val->absolute = absolute_t(v.absolute());
 117                         break;
 118                 default:
 119                         status = grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
 120                                         grpc::string("unkown value type"));
 121                         break;
 122                 }
 123
 124                 if (!status.ok())
 125                         break;
 126         }
 127         if (status.ok()) {
 128                 vl->values = values;
 129                 vl->values_len = values_len;
 130         }
 131         else if (values) {
 132                 free(values);
 133         }
 134
 135         return status;
 136 } /* unmarshal_value_list() */
 137
 138 /*
 139  * request call objects
 140  */
 141
 142 class Call
 143 {
 144 public:
 145         Call(collectd::Collectd::AsyncService *service, grpc::ServerCompletionQueue *cq)
 146                 : service_(service), cq_(cq), status_(CREATE)
 147         { }
 148
 149         virtual ~Call()
 150         { }
 151
 152         void Handle()
 153         {
 154                 if (status_ == CREATE) {
 155                         Create();
 156                         status_ = PROCESS;
 157                 }
 158                 else if (status_ == PROCESS) {
 159                         Process();
 160                         status_ = FINISH;
 161                 }
 162                 else {
 163                         GPR_ASSERT(status_ == FINISH);
 164                         Finish();
 165                 }
 166         } /* Handle() */
 167
 168 protected:
 169         virtual void Create() = 0;
 170         virtual void Process() = 0;
 171         virtual void Finish() = 0;
 172
 173         collectd::Collectd::AsyncService *service_;
 174         grpc::ServerCompletionQueue *cq_;
 175         grpc::ServerContext ctx_;
 176
 177 private:
 178         enum CallStatus { CREATE, PROCESS, FINISH };
 179         CallStatus status_;
 180 }; /* class Call */
 181
 182 class DispatchValuesCall : public Call
 183 {
 184 public:
 185         DispatchValuesCall(collectd::Collectd::AsyncService *service, grpc::ServerCompletionQueue *cq)
 186                 : Call(service, cq), responder_(&ctx_)
 187         {
 188                 Handle();
 189         } /* DispatchValuesCall() */
 190
 191         virtual ~DispatchValuesCall()
 192         { }
 193
 194 private:
 195         void Create()
 196         {
 197                 service_->RequestDispatchValues(&ctx_, &request_, &responder_, cq_, cq_, this);
 198         } /* Create() */
 199
 200         void Process()
 201         {
 202                 // Add a new request object to the queue.
 203                 new DispatchValuesCall(service_, cq_);
 204
 205                 value_list_t vl = VALUE_LIST_INIT;
 206                 auto status = unmarshal_value_list(request_.values(), &vl);
 207                 if (!status.ok()) {
 208                         responder_.Finish(reply_, status, this);
 209                         return;
 210                 }
 211
 212                 if (plugin_dispatch_values(&vl))
 213                         status = grpc::Status(grpc::StatusCode::INTERNAL,
 214                                         grpc::string("failed to enqueue values for writing"));
 215
 216                 responder_.Finish(reply_, status, this);
 217         } /* Process() */
 218
 219         void Finish()
 220         {
 221                 delete this;
 222         } /* Finish() */
 223
 224         collectd::DispatchValuesRequest request_;
 225         collectd::DispatchValuesReply reply_;
 226
 227         grpc::ServerAsyncResponseWriter<collectd::DispatchValuesReply> responder_;
 228 };
 229
 230 /*
 231  * gRPC server implementation
 232  */
 233
 234 class CollectdServer final
 235 {
 236 public:
 237         void Start()
 238         {
 239                 // TODO: make configurable
 240                 auto auth = grpc::InsecureServerCredentials();
 241
 242                 grpc::ServerBuilder builder;
 243
 244                 if (!listeners_num) {
 245                         std::string default_addr("0.0.0.0:50051");
 246                         builder.AddListeningPort(default_addr, auth);
 247                         INFO("grpc: Listening on %s", default_addr.c_str());
 248                 }
 249                 else {
 250                         size_t i;
 251                         for (i = 0; i < listeners_num; i++) {
 252                                 auto l = listeners[i];
 253                                 std::string addr(l.addr);
 254                                 addr += std::string(":") + std::string(l.port);
 255                                 builder.AddListeningPort(addr, auth);
 256                                 INFO("grpc: Listening on %s", addr.c_str());
 257                         }
 258                 }
 259
 260                 builder.RegisterAsyncService(&service_);
 261                 cq_ = builder.AddCompletionQueue();
 262                 server_ = builder.BuildAndStart();
 263         } /* Start() */
 264
 265         void Shutdown()
 266         {
 267                 server_->Shutdown();
 268                 cq_->Shutdown();
 269         } /* Shutdown() */
 270
 271         void Mainloop()
 272         {
 273                 // Register request types.
 274                 new DispatchValuesCall(&service_, cq_.get());
 275
 276                 while (true) {
 277                         void *req = NULL;
 278                         bool ok = false;
 279
 280                         if (!cq_->Next(&req, &ok))
 281                                 break; // Queue shut down.
 282                         if (!ok) {
 283                                 ERROR("grpc: Failed to read from queue");
 284                                 break;
 285                         }
 286
 287                         static_cast<Call *>(req)->Handle();
 288                 }
 289         } /* Mainloop() */
 290
 291 private:
 292         collectd::Collectd::AsyncService service_;
 293
 294         std::unique_ptr<grpc::Server> server_;
 295         std::unique_ptr<grpc::ServerCompletionQueue> cq_;
 296 }; /* class CollectdServer */
 297
 298 static CollectdServer *server = nullptr;
 299
 300 /*
 301  * collectd plugin interface
 302  */
 303
 304 extern "C" {
 305         static pthread_t *workers;
 306         static size_t workers_num = 5;
 307
 308         static void *worker_thread(void *arg)
 309         {
 310                 CollectdServer *s = (CollectdServer *)arg;
 311                 s->Mainloop();
 312                 return NULL;
 313         } /* worker_thread() */
 314
 315         static int c_grpc_config_listen(oconfig_item_t *ci)
 316         {
 317                 listener_t *listener;
 318                 int i;
 319
 320                 if ((ci->values_num != 2)
 321                                 || (ci->values[0].type != OCONFIG_TYPE_STRING)
 322                                 || (ci->values[1].type != OCONFIG_TYPE_STRING)) {
 323                         ERROR("grpc: The `%s` config option needs exactly "
 324                                         "two string argument (address and port).", ci->key);
 325                         return -1;
 326                 }
 327
 328                 listener = (listener_t *)realloc(listeners,
 329                                 (listeners_num + 1) * sizeof(*listeners));
 330                 if (!listener) {
 331                         ERROR("grpc: Failed to allocate listeners");
 332                         return -1;
 333                 }
 334                 listeners = listener;
 335                 listener = listeners + listeners_num;
 336                 listeners_num++;
 337
 338                 listener->addr = strdup(ci->values[0].value.string);
 339                 listener->port = strdup(ci->values[1].value.string);
 340
 341                 for (i = 0; i < ci->children_num; i++) {
 342                         oconfig_item_t *child = ci->children + i;
 343                         WARNING("grpc: Option `%s` not allowed in <%s> block.",
 344                                         child->key, ci->key);
 345                 }
 346
 347                 return 0;
 348         } /* c_grpc_config_listen() */
 349
 350         static int c_grpc_config(oconfig_item_t *ci)
 351         {
 352                 int i;
 353
 354                 for (i = 0; i < ci->children_num; i++) {
 355                         oconfig_item_t *child = ci->children + i;
 356
 357                         if (!strcasecmp("Listen", child->key)) {
 358                                 if (c_grpc_config_listen(child))
 359                                         return -1;
 360                         }
 361                         else if (!strcasecmp("WorkerThreads", child->key)) {
 362                                 int n;
 363                                 if (cf_util_get_int(child, &n))
 364                                         return -1;
 365                                 workers_num = (size_t)n;
 366                         }
 367                         else {
 368                                 WARNING("grpc: Option `%s` not allowed here.", child->key);
 369                         }
 370                 }
 371
 372                 return 0;
 373         } /* c_grpc_config() */
 374
 375         static int c_grpc_init(void)
 376         {
 377                 server = new CollectdServer();
 378                 size_t i;
 379
 380                 if (! server) {
 381                         ERROR("grpc: Failed to create server");
 382                         return -1;
 383                 }
 384
 385                 workers = (pthread_t *)calloc(workers_num, sizeof(*workers));
 386                 if (! workers) {
 387                         delete server;
 388                         server = nullptr;
 389
 390                         ERROR("grpc: Failed to allocate worker threads");
 391                         return -1;
 392                 }
 393
 394                 server->Start();
 395                 for (i = 0; i < workers_num; i++) {
 396                         pthread_create(&workers[i], /* attr = */ NULL,
 397                                         worker_thread, server);
 398                 }
 399                 INFO("grpc: Started %zu workers", workers_num);
 400                 return 0;
 401         } /* c_grpc_init() */
 402
 403         static int c_grpc_shutdown(void)
 404         {
 405                 size_t i;
 406
 407                 if (!server)
 408                         return -1;
 409
 410                 server->Shutdown();
 411
 412                 INFO("grpc: Waiting for %zu workers to terminate", workers_num);
 413                 for (i = 0; i < workers_num; i++)
 414                         pthread_join(workers[i], NULL);
 415                 free(workers);
 416                 workers = NULL;
 417                 workers_num = 0;
 418
 419                 delete server;
 420                 server = nullptr;
 421
 422                 return 0;
 423         } /* c_grpc_shutdown() */
 424
 425         void module_register(void)
 426         {
 427                 plugin_register_complex_config("grpc", c_grpc_config);
 428                 plugin_register_init("grpc", c_grpc_init);
 429                 plugin_register_shutdown("grpc", c_grpc_shutdown);
 430         } /* module_register() */
 431 } /* extern "C" */
 432
 433 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */