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
 102 static char *attr_values[ARRAY_SIZE(attr_table)];
 103 static pthread_mutex_t attr_mutex = PTHREAD_MUTEX_INITIALIZER;
 104
 105 static void mqtt_publish(const char *topic, const char *fmt, ...)
 106 {
 107         va_list args;
 108         va_start(args, fmt);
 109         char m[256];
 110         int l = vsnprintf(m, sizeof(m), fmt, args);
 111         if (mosquitto_publish(mosq, NULL, topic, l, m, 0, true) != MOSQ_ERR_SUCCESS)
 112                 msg(L_ERROR, "Mosquitto: publish failed");
 113         va_end(args);
 114 }
 115
 116 static void mqtt_conn_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, int status)
 117 {
 118         if (!status) {
 119                 msg(L_DEBUG, "MQTT: Connection established, subscribing");
 120                 if (mosquitto_subscribe(mosq, NULL, "burrow/#", 1) != MOSQ_ERR_SUCCESS)
 121                         die("Mosquitto: subscribe failed");
 122
 123                 mqtt_publish("status/prometheus", "ok");
 124         }
 125 }
 126
 127 static void mqtt_log_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, int level, const char *message)
 128 {
 129         // msg(L_INFO, "MQTT(%d): %s", level, message);
 130 }
 131
 132 static void mqtt_msg_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, const struct mosquitto_message *m)
 133 {
 134         char val[256];
 135         if (m->payloadlen >= sizeof(val) - 1) {
 136                 msg(L_ERROR, "Invalid value for topic %s", m->topic);
 137                 return;
 138         }
 139         memcpy(val, m->payload, m->payloadlen);
 140         val[m->payloadlen] = 0;
 141         msg(L_DEBUG, "MQTT < %s %s", m->topic, val);
 142
 143         for (uint i=0; i < ARRAY_SIZE(attr_table); i++) {
 144                 if (attr_table[i].topic && !strcmp(attr_table[i].topic, m->topic)) {
 145                         pthread_mutex_lock(&attr_mutex);
 146                         if (attr_values[i]) {
 147                                 xfree(attr_values[i]);
 148                                 attr_values[i] = NULL;
 149                         }
 150                         if (val[0])
 151                                 attr_values[i] = xstrdup(val);
 152                         pthread_mutex_unlock(&attr_mutex);
 153                 }
 154         }
 155 }
 156
 157 struct http {
 158         struct mempool *mp;
 159         int sk;
 160         char *iobuf;
 161         uint iobuf_pos, iobuf_max;
 162         char *linebuf;
 163         struct fbpool fbpool;
 164 };
 165
 166 #define IO_TIMEOUT 60000        // in ms
 167 #define IOBUF_SIZE 1024
 168 #define LINEBUF_SIZE 1024
 169
 170 static void http_send(struct http *http)
 171 {
 172         byte *buf = fbpool_end(&http->fbpool);
 173         uint len = mp_size(http->mp, buf);
 174
 175         while (len) {
 176                 struct pollfd pfd = { .fd = http->sk, .events = POLLOUT, .revents = 0 };
 177                 int res = poll(&pfd, 1, IO_TIMEOUT);
 178                 if (res < 0)
 179                         die("Poll failed: %m");
 180                 if (!res) {
 181                         msg(L_ERROR, "HTTP write timed out");
 182                         return;
 183                 }
 184
 185                 res = write(http->sk, buf, len);
 186                 if (res < 0) {
 187                         msg(L_ERROR, "HTTP write failed: %m");
 188                         return;
 189                 }
 190                 buf += res;
 191                 len -= res;
 192         }
 193 }
 194
 195 static void http_error(struct http *http, const char *err)
 196 {
 197         msg(L_INFO, "HTTP error: %s", err);
 198         fbpool_start(&http->fbpool, http->mp, 0);
 199         bprintf(&http->fbpool.fb, "HTTP/1.1 %s\r\n", err);
 200         http_send(http);
 201 }
 202
 203 static int http_get_char(struct http *http) {
 204         if (http->iobuf_pos >= http->iobuf_max) {
 205                 struct pollfd pfd = { .fd = http->sk, .events = POLLIN, .revents = 0 };
 206                 int res = poll(&pfd, 1, IO_TIMEOUT);
 207                 if (res < 0)
 208                         die("Poll failed: %m");
 209                 if (!res) {
 210                         msg(L_ERROR, "HTTP read timed out");
 211                         return -1;
 212                 }
 213                 int len = read(http->sk, http->iobuf, IOBUF_SIZE);
 214                 if (len < 0) {
 215                         msg(L_ERROR, "HTTP read error: %m");
 216                         return -1;
 217                 }
 218                 if (!len) {
 219                         msg(L_ERROR, "HTTP connection closed");
 220                         return -1;
 221                 }
 222                 http->iobuf_pos = 0;
 223                 http->iobuf_max = len;
 224         }
 225         return http->iobuf[http->iobuf_pos++];
 226 }
 227
 228 static bool http_get_line(struct http *http)
 229 {
 230         uint i = 0;
 231         for (;;) {
 232                 int c = http_get_char(http);
 233                 if (c < 0)
 234                         return false;
 235                 if (c == '\n') {
 236                         if (i > 0 && http->linebuf[i-1] == '\r')
 237                                 i--;
 238                         http->linebuf[i] = 0;
 239                         return true;
 240                 }
 241                 if (i >= IOBUF_SIZE-1) {
 242                         http_error(http, "400 Line too long");
 243                         return false;
 244                 }
 245                 http->linebuf[i++] = c;
 246         }
 247 }
 248
 249 static void http_answer(struct fastbuf *fb)
 250 {
 251         char val[256], *w[2];
 252         time_t now = time(NULL);
 253
 254         for (uint i=0; i < ARRAY_SIZE(attr_table); i++) {
 255                 const struct attr *a = &attr_table[i];
 256
 257                 pthread_mutex_lock(&attr_mutex);
 258                 snprintf(val, sizeof(val), "%s", attr_values[i] ? : "");
 259                 pthread_mutex_unlock(&attr_mutex);
 260
 261                 if (!val[0])
 262                         continue;
 263                 int fields = str_wordsplit(val, w, ARRAY_SIZE(w));
 264                 if (fields < 1)
 265                         continue;
 266                 if (fields >= 2) {
 267                         time_t t = atoll(w[1]);
 268                         if (t < now - MEASUREMENT_TIMEOUT)
 269                                 continue;
 270                 }
 271
 272                 if (a->help)
 273                         bprintf(fb, "# HELP %s %s\n", a->metric, a->help);
 274                 if (a->type)
 275                         bprintf(fb, "# TYPE %s %s\n", a->metric, a->type);
 276                 bprintf(fb, "%s %s", a->metric, val);
 277 #if 0
 278                 // Prometheus does not like our timestamps -- why?
 279                 if (fields >= 2)
 280                         bprintf(fb, " %s", w[1]);
 281 #endif
 282                 bputc(fb, '\n');
 283         }
 284 }
 285
 286 static void http_connection(struct http *http)
 287 {
 288         http->iobuf = mp_alloc(http->mp, IOBUF_SIZE);
 289         http->linebuf = mp_alloc(http->mp, LINEBUF_SIZE);
 290         fbpool_init(&http->fbpool);
 291
 292         if (!http_get_line(http))
 293                 return;
 294         // msg(L_DEBUG, "Request line: <%s>", http->linebuf);
 295         char *words[3];
 296         if (str_wordsplit(http->linebuf, words, 3) != 3) {
 297                 http_error(http, "400 Invalid request line");
 298                 return;
 299         }
 300         if (strcmp(words[0], "GET")) {
 301                 http_error(http, "501 Method not implemented");
 302                 return;
 303         }
 304
 305         for (;;) {
 306                 if (!http_get_line(http))
 307                         return;
 308                 if (!http->linebuf[0])
 309                         break;
 310                 // msg(L_DEBUG, "Header line: <%s>", http->linebuf);
 311         }
 312
 313         fbpool_start(&http->fbpool, http->mp, 0);
 314         struct fastbuf *fb = &http->fbpool.fb;
 315         bprintf(fb, "HTTP/1.1 200 OK\r\n");
 316         bprintf(fb, "Content-type: text/plain; version=0.0.4\r\n");
 317         bprintf(fb, "\r\n");
 318         http_answer(fb);
 319         http_send(http);
 320 }
 321
 322 static int use_daemon;
 323 static int use_debug;
 324
 325 static struct opt_section options = {
 326         OPT_ITEMS {
 327                 OPT_HELP("A daemon for controlling the solid state relay module via MQTT"),
 328                 OPT_HELP(""),
 329                 OPT_HELP("Options:"),
 330                 OPT_BOOL('d', "debug", use_debug, 0, "\tLog debugging messages"),
 331                 OPT_BOOL(0, "daemon", use_daemon, 0, "\tDaemonize"),
 332                 OPT_HELP_OPTION,
 333                 OPT_CONF_OPTIONS,
 334                 OPT_END
 335         }
 336 };
 337
 338 int main(int argc UNUSED, char **argv)
 339 {
 340         log_init(argv[0]);
 341         opt_parse(&options, argv+1);
 342
 343         if (use_daemon) {
 344                 struct log_stream *ls = log_new_syslog("daemon", LOG_PID);
 345                 log_set_default_stream(ls);
 346         }
 347         if (!use_debug)
 348                 log_default_stream()->levels &= ~(1U << L_DEBUG);
 349
 350         mosquitto_lib_init();
 351         mosq = mosquitto_new("prometheus", 1, NULL);
 352         if (!mosq)
 353                 die("Mosquitto: initialization failed");
 354
 355         mosquitto_connect_callback_set(mosq, mqtt_conn_callback);
 356         mosquitto_log_callback_set(mosq, mqtt_log_callback);
 357         mosquitto_message_callback_set(mosq, mqtt_msg_callback);
 358
 359         if (mosquitto_will_set(mosq, "status/prometheus", 4, "dead", 0, true) != MOSQ_ERR_SUCCESS)
 360                 die("Mosquitto: unable to set will");
 361
 362         if (mosquitto_connect_async(mosq, "10.32.184.5", 1883, 60) != MOSQ_ERR_SUCCESS)
 363                 die("Mosquitto: connect failed");
 364
 365         if (mosquitto_loop_start(mosq))
 366                 die("Mosquitto: cannot start service thread");
 367
 368         int listen_sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 369         if (listen_sk < 0)
 370                 die("Cannot create listening socket: %m");
 371
 372         int one = 1;
 373         if (setsockopt(listen_sk, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
 374                 die("Cannot set SO_REUSEADDR: %m");
 375
 376         struct sockaddr_in sin = { .sin_family = AF_INET, .sin_port = htons(1422), .sin_addr = INADDR_ANY };
 377         if (bind(listen_sk, (const struct sockaddr *) &sin, sizeof(sin)) < 0)
 378                 die("Cannot bind listening socket: %m");
 379
 380         if (listen(listen_sk, 64) < 0)
 381                 die("Cannot listen: %m");
 382
 383         for (;;) {
 384                 int sk = accept(listen_sk, NULL, NULL);
 385                 if (sk < 0) {
 386                         msg(L_ERROR, "HTTP accept failed: %m");
 387                         continue;
 388                 }
 389                 msg(L_DEBUG, "HTTP accepted connection");
 390                 struct mempool *mp = mp_new(4096);
 391                 struct http *http = mp_alloc_zero(mp, sizeof(*http));
 392                 http->mp = mp;
 393                 http->sk = sk;
 394                 http_connection(http);
 395                 mp_delete(mp);
 396                 close(sk);
 397         }
 398 }