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_machinarium",
  78                 .help = "Temperature in the Machinarium [degC]",
  79                 .type = "gauge",
  80                 .topic = "burrow/temp/machinarium"
  81         },
  82         {
  83                 .metric = "rh_garage",
  84                 .help = "Relative humidity in the garage [%]",
  85                 .type = "gauge",
  86                 .topic = "burrow/temp/garage-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 = "loft_fan",
 102                 .help = "Fan velocity in the loft (0-3)",
 103                 .type = "gauge",
 104                 .topic = "burrow/loft/fan"
 105         },
 106         {
 107                 .metric = "loft_circulation",
 108                 .help = "Circulation pump in the loft (0-1)",
 109                 .type = "gauge",
 110                 .topic = "burrow/loft/circulation"
 111         },
 112 };
 113
 114 static char *attr_values[ARRAY_SIZE(attr_table)];
 115 static pthread_mutex_t attr_mutex = PTHREAD_MUTEX_INITIALIZER;
 116
 117 static void mqtt_publish(const char *topic, const char *fmt, ...)
 118 {
 119         va_list args;
 120         va_start(args, fmt);
 121         char m[256];
 122         int l = vsnprintf(m, sizeof(m), fmt, args);
 123         if (mosquitto_publish(mosq, NULL, topic, l, m, 0, true) != MOSQ_ERR_SUCCESS)
 124                 msg(L_ERROR, "Mosquitto: publish failed");
 125         va_end(args);
 126 }
 127
 128 static void mqtt_conn_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, int status)
 129 {
 130         if (!status) {
 131                 msg(L_DEBUG, "MQTT: Connection established, subscribing");
 132                 if (mosquitto_subscribe(mosq, NULL, "burrow/#", 1) != MOSQ_ERR_SUCCESS)
 133                         die("Mosquitto: subscribe failed");
 134
 135                 mqtt_publish("status/prometheus", "ok");
 136         }
 137 }
 138
 139 static void mqtt_log_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, int level, const char *message)
 140 {
 141         // msg(L_INFO, "MQTT(%d): %s", level, message);
 142 }
 143
 144 static void mqtt_msg_callback(struct mosquitto *mosq UNUSED, void *obj UNUSED, const struct mosquitto_message *m)
 145 {
 146         char val[256];
 147         if (m->payloadlen >= sizeof(val) - 1) {
 148                 msg(L_ERROR, "Invalid value for topic %s", m->topic);
 149                 return;
 150         }
 151         memcpy(val, m->payload, m->payloadlen);
 152         val[m->payloadlen] = 0;
 153         msg(L_DEBUG, "MQTT < %s %s", m->topic, val);
 154
 155         for (uint i=0; i < ARRAY_SIZE(attr_table); i++) {
 156                 if (attr_table[i].topic && !strcmp(attr_table[i].topic, m->topic)) {
 157                         pthread_mutex_lock(&attr_mutex);
 158                         if (attr_values[i]) {
 159                                 xfree(attr_values[i]);
 160                                 attr_values[i] = NULL;
 161                         }
 162                         if (val[0])
 163                                 attr_values[i] = xstrdup(val);
 164                         pthread_mutex_unlock(&attr_mutex);
 165                 }
 166         }
 167 }
 168
 169 struct http {
 170         struct mempool *mp;
 171         int sk;
 172         char *iobuf;
 173         uint iobuf_pos, iobuf_max;
 174         char *linebuf;
 175         struct fbpool fbpool;
 176 };
 177
 178 #define IO_TIMEOUT 60000        // in ms
 179 #define IOBUF_SIZE 1024
 180 #define LINEBUF_SIZE 1024
 181
 182 static void http_send(struct http *http)
 183 {
 184         byte *buf = fbpool_end(&http->fbpool);
 185         uint len = mp_size(http->mp, buf);
 186
 187         while (len) {
 188                 struct pollfd pfd = { .fd = http->sk, .events = POLLOUT, .revents = 0 };
 189                 int res = poll(&pfd, 1, IO_TIMEOUT);
 190                 if (res < 0)
 191                         die("Poll failed: %m");
 192                 if (!res) {
 193                         msg(L_ERROR, "HTTP write timed out");
 194                         return;
 195                 }
 196
 197                 res = write(http->sk, buf, len);
 198                 if (res < 0) {
 199                         msg(L_ERROR, "HTTP write failed: %m");
 200                         return;
 201                 }
 202                 buf += res;
 203                 len -= res;
 204         }
 205 }
 206
 207 static void http_error(struct http *http, const char *err)
 208 {
 209         msg(L_INFO, "HTTP error: %s", err);
 210         fbpool_start(&http->fbpool, http->mp, 0);
 211         bprintf(&http->fbpool.fb, "HTTP/1.1 %s\r\n", err);
 212         http_send(http);
 213 }
 214
 215 static int http_get_char(struct http *http) {
 216         if (http->iobuf_pos >= http->iobuf_max) {
 217                 struct pollfd pfd = { .fd = http->sk, .events = POLLIN, .revents = 0 };
 218                 int res = poll(&pfd, 1, IO_TIMEOUT);
 219                 if (res < 0)
 220                         die("Poll failed: %m");
 221                 if (!res) {
 222                         msg(L_ERROR, "HTTP read timed out");
 223                         return -1;
 224                 }
 225                 int len = read(http->sk, http->iobuf, IOBUF_SIZE);
 226                 if (len < 0) {
 227                         msg(L_ERROR, "HTTP read error: %m");
 228                         return -1;
 229                 }
 230                 if (!len) {
 231                         msg(L_ERROR, "HTTP connection closed");
 232                         return -1;
 233                 }
 234                 http->iobuf_pos = 0;
 235                 http->iobuf_max = len;
 236         }
 237         return http->iobuf[http->iobuf_pos++];
 238 }
 239
 240 static bool http_get_line(struct http *http)
 241 {
 242         uint i = 0;
 243         for (;;) {
 244                 int c = http_get_char(http);
 245                 if (c < 0)
 246                         return false;
 247                 if (c == '\n') {
 248                         if (i > 0 && http->linebuf[i-1] == '\r')
 249                                 i--;
 250                         http->linebuf[i] = 0;
 251                         return true;
 252                 }
 253                 if (i >= IOBUF_SIZE-1) {
 254                         http_error(http, "400 Line too long");
 255                         return false;
 256                 }
 257                 http->linebuf[i++] = c;
 258         }
 259 }
 260
 261 static void http_answer(struct fastbuf *fb)
 262 {
 263         char val[256], *w[2];
 264         time_t now = time(NULL);
 265
 266         for (uint i=0; i < ARRAY_SIZE(attr_table); i++) {
 267                 const struct attr *a = &attr_table[i];
 268
 269                 pthread_mutex_lock(&attr_mutex);
 270                 snprintf(val, sizeof(val), "%s", attr_values[i] ? : "");
 271                 pthread_mutex_unlock(&attr_mutex);
 272
 273                 if (!val[0])
 274                         continue;
 275                 int fields = str_wordsplit(val, w, ARRAY_SIZE(w));
 276                 if (fields < 1)
 277                         continue;
 278                 if (fields >= 2) {
 279                         time_t t = atoll(w[1]);
 280                         if (t < now - MEASUREMENT_TIMEOUT)
 281                                 continue;
 282                 }
 283
 284                 if (a->help)
 285                         bprintf(fb, "# HELP %s %s\n", a->metric, a->help);
 286                 if (a->type)
 287                         bprintf(fb, "# TYPE %s %s\n", a->metric, a->type);
 288                 bprintf(fb, "%s %s", a->metric, val);
 289 #if 0
 290                 // Prometheus does not like our timestamps -- why?
 291                 if (fields >= 2)
 292                         bprintf(fb, " %s", w[1]);
 293 #endif
 294                 bputc(fb, '\n');
 295         }
 296 }
 297
 298 static void http_connection(struct http *http)
 299 {
 300         http->iobuf = mp_alloc(http->mp, IOBUF_SIZE);
 301         http->linebuf = mp_alloc(http->mp, LINEBUF_SIZE);
 302         fbpool_init(&http->fbpool);
 303
 304         if (!http_get_line(http))
 305                 return;
 306         // msg(L_DEBUG, "Request line: <%s>", http->linebuf);
 307         char *words[3];
 308         if (str_wordsplit(http->linebuf, words, 3) != 3) {
 309                 http_error(http, "400 Invalid request line");
 310                 return;
 311         }
 312         if (strcmp(words[0], "GET")) {
 313                 http_error(http, "501 Method not implemented");
 314                 return;
 315         }
 316
 317         for (;;) {
 318                 if (!http_get_line(http))
 319                         return;
 320                 if (!http->linebuf[0])
 321                         break;
 322                 // msg(L_DEBUG, "Header line: <%s>", http->linebuf);
 323         }
 324
 325         fbpool_start(&http->fbpool, http->mp, 0);
 326         struct fastbuf *fb = &http->fbpool.fb;
 327         bprintf(fb, "HTTP/1.1 200 OK\r\n");
 328         bprintf(fb, "Content-type: text/plain; version=0.0.4\r\n");
 329         bprintf(fb, "\r\n");
 330         http_answer(fb);
 331         http_send(http);
 332 }
 333
 334 static int use_daemon;
 335 static int use_debug;
 336
 337 static struct opt_section options = {
 338         OPT_ITEMS {
 339                 OPT_HELP("A daemon for controlling the solid state relay module via MQTT"),
 340                 OPT_HELP(""),
 341                 OPT_HELP("Options:"),
 342                 OPT_BOOL('d', "debug", use_debug, 0, "\tLog debugging messages"),
 343                 OPT_BOOL(0, "daemon", use_daemon, 0, "\tDaemonize"),
 344                 OPT_HELP_OPTION,
 345                 OPT_CONF_OPTIONS,
 346                 OPT_END
 347         }
 348 };
 349
 350 int main(int argc UNUSED, char **argv)
 351 {
 352         log_init(argv[0]);
 353         opt_parse(&options, argv+1);
 354
 355         if (use_daemon) {
 356                 struct log_stream *ls = log_new_syslog("daemon", LOG_PID);
 357                 log_set_default_stream(ls);
 358         }
 359         if (!use_debug)
 360                 log_default_stream()->levels &= ~(1U << L_DEBUG);
 361
 362         mosquitto_lib_init();
 363         mosq = mosquitto_new("prometheus", 1, NULL);
 364         if (!mosq)
 365                 die("Mosquitto: initialization failed");
 366
 367         mosquitto_connect_callback_set(mosq, mqtt_conn_callback);
 368         mosquitto_log_callback_set(mosq, mqtt_log_callback);
 369         mosquitto_message_callback_set(mosq, mqtt_msg_callback);
 370
 371         if (mosquitto_will_set(mosq, "status/prometheus", 4, "dead", 0, true) != MOSQ_ERR_SUCCESS)
 372                 die("Mosquitto: unable to set will");
 373
 374         if (mosquitto_connect_async(mosq, "10.32.184.5", 1883, 60) != MOSQ_ERR_SUCCESS)
 375                 die("Mosquitto: connect failed");
 376
 377         if (mosquitto_loop_start(mosq))
 378                 die("Mosquitto: cannot start service thread");
 379
 380         int listen_sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 381         if (listen_sk < 0)
 382                 die("Cannot create listening socket: %m");
 383
 384         int one = 1;
 385         if (setsockopt(listen_sk, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
 386                 die("Cannot set SO_REUSEADDR: %m");
 387
 388         struct sockaddr_in sin = { .sin_family = AF_INET, .sin_port = htons(1422), .sin_addr = INADDR_ANY };
 389         if (bind(listen_sk, (const struct sockaddr *) &sin, sizeof(sin)) < 0)
 390                 die("Cannot bind listening socket: %m");
 391
 392         if (listen(listen_sk, 64) < 0)
 393                 die("Cannot listen: %m");
 394
 395         for (;;) {
 396                 int sk = accept(listen_sk, NULL, NULL);
 397                 if (sk < 0) {
 398                         msg(L_ERROR, "HTTP accept failed: %m");
 399                         continue;
 400                 }
 401                 msg(L_DEBUG, "HTTP accepted connection");
 402                 struct mempool *mp = mp_new(4096);
 403                 struct http *http = mp_alloc_zero(mp, sizeof(*http));
 404                 http->mp = mp;
 405                 http->sk = sk;
 406                 http_connection(http);
 407                 mp_delete(mp);
 408                 close(sk);
 409         }
 410 }