prometheus/burrow-prometheus.c

   1 /*
   2  *      A gateway between MQTT and Prometheus
   3  *
   4  *      (c) 2018--2019 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_mixed",
 126                 .help = "Temperature of mixed air [degC]",
 127                 .type = "gauge",
 128                 .topic = "burrow/air/mixed",
 129         },
 130         {
 131                 .metric = "air_bypass",
 132                 .help = "Heat exchanger bypass (0-1)",
 133                 .type = "gauge",
 134                 .topic = "burrow/air/bypass"
 135         },
 136         {
 137                 .metric = "air_fan_pwm",
 138                 .help = "Heat exchanger fan PWM (0-255)",
 139                 .type = "gauge",
 140                 .topic = "burrow/air/fan-pwm"
 141         },
 142 };
 143
 144 static char *attr_values[ARRAY_SIZE(attr_table)];
 145 static pthread_mutex_t attr_mutex = PTHREAD_MUTEX_INITIALIZER;
 146
 147 static void mqtt_publish(const char *topic, const char *fmt, ...)
 148 {
 149         va_list args;
 150         va_start(args, fmt);
 151         char m[256];
 152         int l = vsnprintf(m, sizeof(m), fmt, args);
 153         if (mosquitto_publish(mosq, NULL, topic, l, m, 0, true) != MOSQ_ERR_SUCCESS)
 154                 msg(L_ERROR, "Mosquitto: publish failed");
 155         va_end(args);
 156 }
 157
 158 static void mqtt_conn_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, int status)
 159 {
 160         if (!status) {
 161                 msg(L_DEBUG, "MQTT: Connection established, subscribing");
 162                 if (mosquitto_subscribe(mosq, NULL, "burrow/#", 1) != MOSQ_ERR_SUCCESS)
 163                         die("Mosquitto: subscribe failed");
 164
 165                 mqtt_publish("status/prometheus", "ok");
 166         }
 167 }
 168
 169 static void mqtt_log_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, int level, const char *message)
 170 {
 171         // msg(L_INFO, "MQTT(%d): %s", level, message);
 172 }
 173
 174 static void mqtt_msg_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, const struct mosquitto_message *m)
 175 {
 176         char val[256];
 177         if (m->payloadlen >= sizeof(val) - 1) {
 178                 msg(L_ERROR, "Invalid value for topic %s", m->topic);
 179                 return;
 180         }
 181         memcpy(val, m->payload, m->payloadlen);
 182         val[m->payloadlen] = 0;
 183         msg(L_DEBUG, "MQTT < %s %s", m->topic, val);
 184
 185         for (uint i=0; i < ARRAY_SIZE(attr_table); i++) {
 186                 if (attr_table[i].topic && !strcmp(attr_table[i].topic, m->topic)) {
 187                         pthread_mutex_lock(&attr_mutex);
 188                         if (attr_values[i]) {
 189                                 xfree(attr_values[i]);
 190                                 attr_values[i] = NULL;
 191                         }
 192                         if (val[0])
 193                                 attr_values[i] = xstrdup(val);
 194                         pthread_mutex_unlock(&attr_mutex);
 195                 }
 196         }
 197 }
 198
 199 struct http {
 200         struct mempool *mp;
 201         int sk;
 202         char *iobuf;
 203         uint iobuf_pos, iobuf_max;
 204         char *linebuf;
 205         struct fbpool fbpool;
 206 };
 207
 208 #define IO_TIMEOUT 60000        // in ms
 209 #define IOBUF_SIZE 1024
 210 #define LINEBUF_SIZE 1024
 211
 212 static void http_send(struct http *http)
 213 {
 214         byte *buf = fbpool_end(&http->fbpool);
 215         uint len = mp_size(http->mp, buf);
 216
 217         while (len) {
 218                 struct pollfd pfd = { .fd = http->sk, .events = POLLOUT, .revents = 0 };
 219                 int res = poll(&pfd, 1, IO_TIMEOUT);
 220                 if (res < 0)
 221                         die("Poll failed: %m");
 222                 if (!res) {
 223                         msg(L_ERROR, "HTTP write timed out");
 224                         return;
 225                 }
 226
 227                 res = write(http->sk, buf, len);
 228                 if (res < 0) {
 229                         msg(L_ERROR, "HTTP write failed: %m");
 230                         return;
 231                 }
 232                 buf += res;
 233                 len -= res;
 234         }
 235 }
 236
 237 static void http_error(struct http *http, const char *err)
 238 {
 239         msg(L_INFO, "HTTP error: %s", err);
 240         fbpool_start(&http->fbpool, http->mp, 0);
 241         bprintf(&http->fbpool.fb, "HTTP/1.1 %s\r\n", err);
 242         http_send(http);
 243 }
 244
 245 static int http_get_char(struct http *http) {
 246         if (http->iobuf_pos >= http->iobuf_max) {
 247                 struct pollfd pfd = { .fd = http->sk, .events = POLLIN, .revents = 0 };
 248                 int res = poll(&pfd, 1, IO_TIMEOUT);
 249                 if (res < 0)
 250                         die("Poll failed: %m");
 251                 if (!res) {
 252                         msg(L_ERROR, "HTTP read timed out");
 253                         return -1;
 254                 }
 255                 int len = read(http->sk, http->iobuf, IOBUF_SIZE);
 256                 if (len < 0) {
 257                         msg(L_ERROR, "HTTP read error: %m");
 258                         return -1;
 259                 }
 260                 if (!len) {
 261                         msg(L_ERROR, "HTTP connection closed");
 262                         return -1;
 263                 }
 264                 http->iobuf_pos = 0;
 265                 http->iobuf_max = len;
 266         }
 267         return http->iobuf[http->iobuf_pos++];
 268 }
 269
 270 static bool http_get_line(struct http *http)
 271 {
 272         uint i = 0;
 273         for (;;) {
 274                 int c = http_get_char(http);
 275                 if (c < 0)
 276                         return false;
 277                 if (c == '\n') {
 278                         if (i > 0 && http->linebuf[i-1] == '\r')
 279                                 i--;
 280                         http->linebuf[i] = 0;
 281                         return true;
 282                 }
 283                 if (i >= IOBUF_SIZE-1) {
 284                         http_error(http, "400 Line too long");
 285                         return false;
 286                 }
 287                 http->linebuf[i++] = c;
 288         }
 289 }
 290
 291 static void http_answer(struct fastbuf *fb)
 292 {
 293         char val[256], *w[2];
 294         time_t now = time(NULL);
 295
 296         for (uint i=0; i < ARRAY_SIZE(attr_table); i++) {
 297                 const struct attr *a = &attr_table[i];
 298
 299                 pthread_mutex_lock(&attr_mutex);
 300                 snprintf(val, sizeof(val), "%s", attr_values[i] ? : "");
 301                 pthread_mutex_unlock(&attr_mutex);
 302
 303                 if (!val[0])
 304                         continue;
 305                 int fields = str_wordsplit(val, w, ARRAY_SIZE(w));
 306                 if (fields < 1)
 307                         continue;
 308                 if (fields >= 2) {
 309                         time_t t = atoll(w[1]);
 310                         if (t < now - MEASUREMENT_TIMEOUT)
 311                                 continue;
 312                 }
 313
 314                 if (a->help)
 315                         bprintf(fb, "# HELP %s %s\n", a->metric, a->help);
 316                 if (a->type)
 317                         bprintf(fb, "# TYPE %s %s\n", a->metric, a->type);
 318                 bprintf(fb, "%s %s", a->metric, val);
 319 #if 0
 320                 // Prometheus does not like our timestamps -- why?
 321                 if (fields >= 2)
 322                         bprintf(fb, " %s", w[1]);
 323 #endif
 324                 bputc(fb, '\n');
 325         }
 326 }
 327
 328 static void http_connection(struct http *http)
 329 {
 330         http->iobuf = mp_alloc(http->mp, IOBUF_SIZE);
 331         http->linebuf = mp_alloc(http->mp, LINEBUF_SIZE);
 332         fbpool_init(&http->fbpool);
 333
 334         if (!http_get_line(http))
 335                 return;
 336         // msg(L_DEBUG, "Request line: <%s>", http->linebuf);
 337         char *words[3];
 338         if (str_wordsplit(http->linebuf, words, 3) != 3) {
 339                 http_error(http, "400 Invalid request line");
 340                 return;
 341         }
 342         if (strcmp(words[0], "GET")) {
 343                 http_error(http, "501 Method not implemented");
 344                 return;
 345         }
 346
 347         for (;;) {
 348                 if (!http_get_line(http))
 349                         return;
 350                 if (!http->linebuf[0])
 351                         break;
 352                 // msg(L_DEBUG, "Header line: <%s>", http->linebuf);
 353         }
 354
 355         fbpool_start(&http->fbpool, http->mp, 0);
 356         struct fastbuf *fb = &http->fbpool.fb;
 357         bprintf(fb, "HTTP/1.1 200 OK\r\n");
 358         bprintf(fb, "Content-type: text/plain; version=0.0.4\r\n");
 359         bprintf(fb, "\r\n");
 360         http_answer(fb);
 361         http_send(http);
 362 }
 363
 364 static int use_daemon;
 365 static int use_debug;
 366
 367 static struct opt_section options = {
 368         OPT_ITEMS {
 369                 OPT_HELP("A daemon for controlling the solid state relay module via MQTT"),
 370                 OPT_HELP(""),
 371                 OPT_HELP("Options:"),
 372                 OPT_BOOL('d', "debug", use_debug, 0, "\tLog debugging messages"),
 373                 OPT_BOOL(0, "daemon", use_daemon, 0, "\tDaemonize"),
 374                 OPT_HELP_OPTION,
 375                 OPT_CONF_OPTIONS,
 376                 OPT_END
 377         }
 378 };
 379
 380 int main(int argc UNUSED, char **argv)
 381 {
 382         log_init(argv[0]);
 383         opt_parse(&options, argv+1);
 384
 385         if (use_daemon) {
 386                 struct log_stream *ls = log_new_syslog("daemon", LOG_PID);
 387                 log_set_default_stream(ls);
 388         }
 389         if (!use_debug)
 390                 log_default_stream()->levels &= ~(1U << L_DEBUG);
 391
 392         mosquitto_lib_init();
 393         mosq = mosquitto_new("prometheus", 1, NULL);
 394         if (!mosq)
 395                 die("Mosquitto: initialization failed");
 396
 397         mosquitto_connect_callback_set(mosq, mqtt_conn_callback);
 398         mosquitto_log_callback_set(mosq, mqtt_log_callback);
 399         mosquitto_message_callback_set(mosq, mqtt_msg_callback);
 400
 401         if (mosquitto_will_set(mosq, "status/prometheus", 4, "dead", 0, true) != MOSQ_ERR_SUCCESS)
 402                 die("Mosquitto: unable to set will");
 403
 404         if (mosquitto_connect_async(mosq, "10.32.184.5", 1883, 60) != MOSQ_ERR_SUCCESS)
 405                 die("Mosquitto: connect failed");
 406
 407         if (mosquitto_loop_start(mosq))
 408                 die("Mosquitto: cannot start service thread");
 409
 410         int listen_sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 411         if (listen_sk < 0)
 412                 die("Cannot create listening socket: %m");
 413
 414         int one = 1;
 415         if (setsockopt(listen_sk, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
 416                 die("Cannot set SO_REUSEADDR: %m");
 417
 418         struct sockaddr_in sin = { .sin_family = AF_INET, .sin_port = htons(1422), .sin_addr = INADDR_ANY };
 419         if (bind(listen_sk, (const struct sockaddr *) &sin, sizeof(sin)) < 0)
 420                 die("Cannot bind listening socket: %m");
 421
 422         if (listen(listen_sk, 64) < 0)
 423                 die("Cannot listen: %m");
 424
 425         for (;;) {
 426                 int sk = accept(listen_sk, NULL, NULL);
 427                 if (sk < 0) {
 428                         msg(L_ERROR, "HTTP accept failed: %m");
 429                         continue;
 430                 }
 431                 msg(L_DEBUG, "HTTP accepted connection");
 432                 struct mempool *mp = mp_new(4096);
 433                 struct http *http = mp_alloc_zero(mp, sizeof(*http));
 434                 http->mp = mp;
 435                 http->sk = sk;
 436                 http_connection(http);
 437                 mp_delete(mp);
 438                 close(sk);
 439         }
 440 }