prometheus/burrow-prometheus.c

   1 /*
   2  *      A gateway between MQTT and Prometheus
   3  *
   4  *      (c) 2018 Martin Mares <mj@ucw.cz>
   5  */
   6
   7 #include <ucw/lib.h>
   8 #include <ucw/fastbuf.h>
   9 #include <ucw/log.h>
  10 #include <ucw/mempool.h>
  11 #include <ucw/opt.h>
  12 #include <ucw/string.h>
  13
  14 #include <netinet/in.h>
  15 #include <pthread.h>
  16 #include <stdarg.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <sys/poll.h>
  21 #include <sys/socket.h>
  22 #include <syslog.h>
  23 #include <time.h>
  24 #include <unistd.h>
  25
  26 #include <mosquitto.h>
  27
  28 #define MEASUREMENT_TIMEOUT 120
  29
  30 static struct mosquitto *mosq;
  31
  32 struct attr {
  33         const char *metric;
  34         const char *help;
  35         const char *type;
  36         const char *topic;
  37 };
  38
  39 static const struct attr attr_table[] = {
  40         {
  41                 .metric = "temp_loft",
  42                 .help = "Temperature in the loft [degC]",
  43                 .type = "gauge",
  44                 .topic = "burrow/temp/loft",
  45         },
  46         {
  47                 .metric = "loft_fan",
  48                 .help = "Fan speed in the loft (0-3)",
  49                 .type = "gauge",
  50                 .topic = "burrow/loft/fan"
  51         },
  52         {
  53                 .metric = "loft_circ",
  54                 .help = "Warm water circulation (0-1)",
  55                 .type = "gauge",
  56                 .topic = "burrow/loft/circulation"
  57         },
  58         {
  59                 .metric = "temp_ursarium",
  60                 .help = "Temperature in the Ursarium [degC]",
  61                 .type = "gauge",
  62                 .topic = "burrow/temp/ursarium"
  63         },
  64         {
  65                 .metric = "temp_catarium",
  66                 .help = "Temperature in the Catarium [degC]",
  67                 .type = "gauge",
  68                 .topic = "burrow/temp/catarium"
  69         },
  70         {
  71                 .metric = "temp_garage",
  72                 .help = "Temperature in the garage [degC]",
  73                 .type = "gauge",
  74                 .topic = "burrow/temp/garage"
  75         },
  76         {
  77                 .metric = "temp_kitchen",
  78                 .help = "Temperature in the kitchen [degC]",
  79                 .type = "gauge",
  80                 .topic = "burrow/temp/kitchen"
  81         },
  82         {
  83                 .metric = "rh_ursarium",
  84                 .help = "Relative humidity in the Ursarium [%]",
  85                 .type = "gauge",
  86                 .topic = "burrow/temp/ursarium-rh"
  87         },
  88         {
  89                 .metric = "temp_catarium_clock",
  90                 .help = "Temperature on Catarium clock [degC]",
  91                 .type = "gauge",
  92                 .topic = "burrow/temp/clock"
  93         },
  94         {
  95                 .metric = "press_catarium_clock",
  96                 .help = "Pressure on Catarium clock [Pa]",
  97                 .type = "gauge",
  98                 .topic = "burrow/pressure/clock"
  99         },
 100         {
 101                 .metric = "air_inside_intake",
 102                 .help = "Temperature of air intake from inside [degC]",
 103                 .type = "gauge",
 104                 .topic = "burrow/air/inside-intake",
 105         },
 106         {
 107                 .metric = "air_inside_exhaust",
 108                 .help = "Temperature of air exhaust to inside [degC]",
 109                 .type = "gauge",
 110                 .topic = "burrow/air/inside-exhaust",
 111         },
 112         {
 113                 .metric = "air_outside_intake",
 114                 .help = "Temperature of air intake from outside [degC]",
 115                 .type = "gauge",
 116                 .topic = "burrow/air/outside-intake",
 117         },
 118         {
 119                 .metric = "air_outside_exhaust",
 120                 .help = "Temperature of air exhaust to outside [degC]",
 121                 .type = "gauge",
 122                 .topic = "burrow/air/outside-exhaust",
 123         },
 124         {
 125                 .metric = "air_chilled",
 126                 .help = "Temperature of chilled air [degC]",
 127                 .type = "gauge",
 128                 .topic = "burrow/air/chilled",
 129         },
 130 };
 131
 132 static char *attr_values[ARRAY_SIZE(attr_table)];
 133 static pthread_mutex_t attr_mutex = PTHREAD_MUTEX_INITIALIZER;
 134
 135 static void mqtt_publish(const char *topic, const char *fmt, ...)
 136 {
 137         va_list args;
 138         va_start(args, fmt);
 139         char m[256];
 140         int l = vsnprintf(m, sizeof(m), fmt, args);
 141         if (mosquitto_publish(mosq, NULL, topic, l, m, 0, true) != MOSQ_ERR_SUCCESS)
 142                 msg(L_ERROR, "Mosquitto: publish failed");
 143         va_end(args);
 144 }
 145
 146 static void mqtt_conn_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, int status)
 147 {
 148         if (!status) {
 149                 msg(L_DEBUG, "MQTT: Connection established, subscribing");
 150                 if (mosquitto_subscribe(mosq, NULL, "burrow/#", 1) != MOSQ_ERR_SUCCESS)
 151                         die("Mosquitto: subscribe failed");
 152
 153                 mqtt_publish("status/prometheus", "ok");
 154         }
 155 }
 156
 157 static void mqtt_log_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, int level, const char *message)
 158 {
 159         // msg(L_INFO, "MQTT(%d): %s", level, message);
 160 }
 161
 162 static void mqtt_msg_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, const struct mosquitto_message *m)
 163 {
 164         char val[256];
 165         if (m->payloadlen >= sizeof(val) - 1) {
 166                 msg(L_ERROR, "Invalid value for topic %s", m->topic);
 167                 return;
 168         }
 169         memcpy(val, m->payload, m->payloadlen);
 170         val[m->payloadlen] = 0;
 171         msg(L_DEBUG, "MQTT < %s %s", m->topic, val);
 172
 173         for (uint i=0; i < ARRAY_SIZE(attr_table); i++) {
 174                 if (attr_table[i].topic && !strcmp(attr_table[i].topic, m->topic)) {
 175                         pthread_mutex_lock(&attr_mutex);
 176                         if (attr_values[i]) {
 177                                 xfree(attr_values[i]);
 178                                 attr_values[i] = NULL;
 179                         }
 180                         if (val[0])
 181                                 attr_values[i] = xstrdup(val);
 182                         pthread_mutex_unlock(&attr_mutex);
 183                 }
 184         }
 185 }
 186
 187 struct http {
 188         struct mempool *mp;
 189         int sk;
 190         char *iobuf;
 191         uint iobuf_pos, iobuf_max;
 192         char *linebuf;
 193         struct fbpool fbpool;
 194 };
 195
 196 #define IO_TIMEOUT 60000        // in ms
 197 #define IOBUF_SIZE 1024
 198 #define LINEBUF_SIZE 1024
 199
 200 static void http_send(struct http *http)
 201 {
 202         byte *buf = fbpool_end(&http->fbpool);
 203         uint len = mp_size(http->mp, buf);
 204
 205         while (len) {
 206                 struct pollfd pfd = { .fd = http->sk, .events = POLLOUT, .revents = 0 };
 207                 int res = poll(&pfd, 1, IO_TIMEOUT);
 208                 if (res < 0)
 209                         die("Poll failed: %m");
 210                 if (!res) {
 211                         msg(L_ERROR, "HTTP write timed out");
 212                         return;
 213                 }
 214
 215                 res = write(http->sk, buf, len);
 216                 if (res < 0) {
 217                         msg(L_ERROR, "HTTP write failed: %m");
 218                         return;
 219                 }
 220                 buf += res;
 221                 len -= res;
 222         }
 223 }
 224
 225 static void http_error(struct http *http, const char *err)
 226 {
 227         msg(L_INFO, "HTTP error: %s", err);
 228         fbpool_start(&http->fbpool, http->mp, 0);
 229         bprintf(&http->fbpool.fb, "HTTP/1.1 %s\r\n", err);
 230         http_send(http);
 231 }
 232
 233 static int http_get_char(struct http *http) {
 234         if (http->iobuf_pos >= http->iobuf_max) {
 235                 struct pollfd pfd = { .fd = http->sk, .events = POLLIN, .revents = 0 };
 236                 int res = poll(&pfd, 1, IO_TIMEOUT);
 237                 if (res < 0)
 238                         die("Poll failed: %m");
 239                 if (!res) {
 240                         msg(L_ERROR, "HTTP read timed out");
 241                         return -1;
 242                 }
 243                 int len = read(http->sk, http->iobuf, IOBUF_SIZE);
 244                 if (len < 0) {
 245                         msg(L_ERROR, "HTTP read error: %m");
 246                         return -1;
 247                 }
 248                 if (!len) {
 249                         msg(L_ERROR, "HTTP connection closed");
 250                         return -1;
 251                 }
 252                 http->iobuf_pos = 0;
 253                 http->iobuf_max = len;
 254         }
 255         return http->iobuf[http->iobuf_pos++];
 256 }
 257
 258 static bool http_get_line(struct http *http)
 259 {
 260         uint i = 0;
 261         for (;;) {
 262                 int c = http_get_char(http);
 263                 if (c < 0)
 264                         return false;
 265                 if (c == '\n') {
 266                         if (i > 0 && http->linebuf[i-1] == '\r')
 267                                 i--;
 268                         http->linebuf[i] = 0;
 269                         return true;
 270                 }
 271                 if (i >= IOBUF_SIZE-1) {
 272                         http_error(http, "400 Line too long");
 273                         return false;
 274                 }
 275                 http->linebuf[i++] = c;
 276         }
 277 }
 278
 279 static void http_answer(struct fastbuf *fb)
 280 {
 281         char val[256], *w[2];
 282         time_t now = time(NULL);
 283
 284         for (uint i=0; i < ARRAY_SIZE(attr_table); i++) {
 285                 const struct attr *a = &attr_table[i];
 286
 287                 pthread_mutex_lock(&attr_mutex);
 288                 snprintf(val, sizeof(val), "%s", attr_values[i] ? : "");
 289                 pthread_mutex_unlock(&attr_mutex);
 290
 291                 if (!val[0])
 292                         continue;
 293                 int fields = str_wordsplit(val, w, ARRAY_SIZE(w));
 294                 if (fields < 1)
 295                         continue;
 296                 if (fields >= 2) {
 297                         time_t t = atoll(w[1]);
 298                         if (t < now - MEASUREMENT_TIMEOUT)
 299                                 continue;
 300                 }
 301
 302                 if (a->help)
 303                         bprintf(fb, "# HELP %s %s\n", a->metric, a->help);
 304                 if (a->type)
 305                         bprintf(fb, "# TYPE %s %s\n", a->metric, a->type);
 306                 bprintf(fb, "%s %s", a->metric, val);
 307 #if 0
 308                 // Prometheus does not like our timestamps -- why?
 309                 if (fields >= 2)
 310                         bprintf(fb, " %s", w[1]);
 311 #endif
 312                 bputc(fb, '\n');
 313         }
 314 }
 315
 316 static void http_connection(struct http *http)
 317 {
 318         http->iobuf = mp_alloc(http->mp, IOBUF_SIZE);
 319         http->linebuf = mp_alloc(http->mp, LINEBUF_SIZE);
 320         fbpool_init(&http->fbpool);
 321
 322         if (!http_get_line(http))
 323                 return;
 324         // msg(L_DEBUG, "Request line: <%s>", http->linebuf);
 325         char *words[3];
 326         if (str_wordsplit(http->linebuf, words, 3) != 3) {
 327                 http_error(http, "400 Invalid request line");
 328                 return;
 329         }
 330         if (strcmp(words[0], "GET")) {
 331                 http_error(http, "501 Method not implemented");
 332                 return;
 333         }
 334
 335         for (;;) {
 336                 if (!http_get_line(http))
 337                         return;
 338                 if (!http->linebuf[0])
 339                         break;
 340                 // msg(L_DEBUG, "Header line: <%s>", http->linebuf);
 341         }
 342
 343         fbpool_start(&http->fbpool, http->mp, 0);
 344         struct fastbuf *fb = &http->fbpool.fb;
 345         bprintf(fb, "HTTP/1.1 200 OK\r\n");
 346         bprintf(fb, "Content-type: text/plain; version=0.0.4\r\n");
 347         bprintf(fb, "\r\n");
 348         http_answer(fb);
 349         http_send(http);
 350 }
 351
 352 static int use_daemon;
 353 static int use_debug;
 354
 355 static struct opt_section options = {
 356         OPT_ITEMS {
 357                 OPT_HELP("A daemon for controlling the solid state relay module via MQTT"),
 358                 OPT_HELP(""),
 359                 OPT_HELP("Options:"),
 360                 OPT_BOOL('d', "debug", use_debug, 0, "\tLog debugging messages"),
 361                 OPT_BOOL(0, "daemon", use_daemon, 0, "\tDaemonize"),
 362                 OPT_HELP_OPTION,
 363                 OPT_CONF_OPTIONS,
 364                 OPT_END
 365         }
 366 };
 367
 368 int main(int argc UNUSED, char **argv)
 369 {
 370         log_init(argv[0]);
 371         opt_parse(&options, argv+1);
 372
 373         if (use_daemon) {
 374                 struct log_stream *ls = log_new_syslog("daemon", LOG_PID);
 375                 log_set_default_stream(ls);
 376         }
 377         if (!use_debug)
 378                 log_default_stream()->levels &= ~(1U << L_DEBUG);
 379
 380         mosquitto_lib_init();
 381         mosq = mosquitto_new("prometheus", 1, NULL);
 382         if (!mosq)
 383                 die("Mosquitto: initialization failed");
 384
 385         mosquitto_connect_callback_set(mosq, mqtt_conn_callback);
 386         mosquitto_log_callback_set(mosq, mqtt_log_callback);
 387         mosquitto_message_callback_set(mosq, mqtt_msg_callback);
 388
 389         if (mosquitto_will_set(mosq, "status/prometheus", 4, "dead", 0, true) != MOSQ_ERR_SUCCESS)
 390                 die("Mosquitto: unable to set will");
 391
 392         if (mosquitto_connect_async(mosq, "10.32.184.5", 1883, 60) != MOSQ_ERR_SUCCESS)
 393                 die("Mosquitto: connect failed");
 394
 395         if (mosquitto_loop_start(mosq))
 396                 die("Mosquitto: cannot start service thread");
 397
 398         int listen_sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 399         if (listen_sk < 0)
 400                 die("Cannot create listening socket: %m");
 401
 402         int one = 1;
 403         if (setsockopt(listen_sk, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
 404                 die("Cannot set SO_REUSEADDR: %m");
 405
 406         struct sockaddr_in sin = { .sin_family = AF_INET, .sin_port = htons(1422), .sin_addr = INADDR_ANY };
 407         if (bind(listen_sk, (const struct sockaddr *) &sin, sizeof(sin)) < 0)
 408                 die("Cannot bind listening socket: %m");
 409
 410         if (listen(listen_sk, 64) < 0)
 411                 die("Cannot listen: %m");
 412
 413         for (;;) {
 414                 int sk = accept(listen_sk, NULL, NULL);
 415                 if (sk < 0) {
 416                         msg(L_ERROR, "HTTP accept failed: %m");
 417                         continue;
 418                 }
 419                 msg(L_DEBUG, "HTTP accepted connection");
 420                 struct mempool *mp = mp_new(4096);
 421                 struct http *http = mp_alloc_zero(mp, sizeof(*http));
 422                 http->mp = mp;
 423                 http->sk = sk;
 424                 http_connection(http);
 425                 mp_delete(mp);
 426                 close(sk);
 427         }
 428 }