7adc7f7196cd46589fa0e8e0070db844e62701e3
1 /**
2 * collectd - src/mqtt.c
3 * Copyright (C) 2014 Marc Falzon <marc at baha dot mu>
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 **/
24 // Reference: http://mosquitto.org/api/files/mosquitto-h.html
27 #include "collectd.h"
28 #include "common.h"
29 #include "plugin.h"
30 #include "utils_cache.h"
31 #include "utils_complain.h"
33 #include <pthread.h>
35 #include <mosquitto.h>
37 #define MQTT_MAX_TOPIC_SIZE 1024
38 #define MQTT_MAX_MESSAGE_SIZE MQTT_MAX_TOPIC_SIZE + 1024
39 #define MQTT_DEFAULT_HOST "localhost"
40 #define MQTT_DEFAULT_PORT 1883
41 #define MQTT_DEFAULT_CLIENT_ID "collectd"
42 #define MQTT_DEFAULT_TOPIC_PREFIX "collectd"
44 /*
45 * Data types
46 */
47 struct mqtt_client_conf
48 {
49 struct mosquitto *mosq;
50 bool connected;
51 char *host;
52 int port;
53 char *client_id;
54 char *topic_prefix;
55 c_complain_t complaint_cantpublish;
56 pthread_mutex_t lock;
57 };
59 static char const *mosquitto_strerror (int code)
60 {
61 switch (code)
62 {
63 case MOSQ_ERR_SUCCESS: return "MOSQ_ERR_SUCCESS";
64 case MOSQ_ERR_NOMEM: return "MOSQ_ERR_NOMEM";
65 case MOSQ_ERR_PROTOCOL: return "MOSQ_ERR_PROTOCOL";
66 case MOSQ_ERR_INVAL: return "MOSQ_ERR_INVAL";
67 case MOSQ_ERR_NO_CONN: return "MOSQ_ERR_NO_CONN";
68 case MOSQ_ERR_CONN_REFUSED: return "MOSQ_ERR_CONN_REFUSED";
69 case MOSQ_ERR_NOT_FOUND: return "MOSQ_ERR_NOT_FOUND";
70 case MOSQ_ERR_CONN_LOST: return "MOSQ_ERR_CONN_LOST";
71 case MOSQ_ERR_SSL: return "MOSQ_ERR_SSL";
72 case MOSQ_ERR_PAYLOAD_SIZE: return "MOSQ_ERR_PAYLOAD_SIZE";
73 case MOSQ_ERR_NOT_SUPPORTED: return "MOSQ_ERR_NOT_SUPPORTED";
74 case MOSQ_ERR_AUTH: return "MOSQ_ERR_AUTH";
75 case MOSQ_ERR_ACL_DENIED: return "MOSQ_ERR_ACL_DENIED";
76 case MOSQ_ERR_UNKNOWN: return "MOSQ_ERR_UNKNOWN";
77 case MOSQ_ERR_ERRNO: return "MOSQ_ERR_ERRNO";
78 }
80 return "UNKNOWN ERROR CODE";
81 }
83 /*
84 * Functions
85 */
86 static int mqtt_reconnect_broker (struct mqtt_client_conf *conf)
87 {
88 int status;
90 if (conf->connected)
91 return (0);
93 pthread_mutex_lock (&conf->lock);
95 status = mosquitto_reconnect (conf->mosq);
97 if (status != MOSQ_ERR_SUCCESS) {
98 ERROR ("mqtt_connect_broker: mosquitto_connect failed: %s",
99 (status == MOSQ_ERR_ERRNO ?
100 strerror(errno) : mosquitto_strerror (status)));
101 pthread_mutex_unlock (&conf->lock);
102 return (-1);
103 }
105 conf->connected = true;
107 c_release (LOG_INFO,
108 &conf->complaint_cantpublish,
109 "mqtt plugin: successfully reconnected to broker \"%s:%d\"",
110 conf->host, conf->port);
112 pthread_mutex_unlock (&conf->lock);
114 return (0);
115 } /* mqtt_reconnect_broker */
117 static int mqtt_publish_message (struct mqtt_client_conf *conf, char *topic,
118 void const *payload, size_t payload_len)
119 {
120 char errbuf[1024];
121 int status;
123 status = mosquitto_publish(conf->mosq,
124 /* message id */ NULL,
125 topic,
126 (int) payload_len,
127 payload,
128 /* qos */ 0,
129 /* retain */ false);
131 if (status != MOSQ_ERR_SUCCESS)
132 {
133 c_complain (LOG_ERR,
134 &conf->complaint_cantpublish,
135 "plugin mqtt: mosquitto_publish failed: %s",
136 status == MOSQ_ERR_ERRNO ?
137 sstrerror(errno, errbuf, sizeof (errbuf)) :
138 mosquitto_strerror(status));
139 /*
140 Mark our connection "down" regardless of the error as a safety measure;
141 we will try to reconnect the next time we have to publish a message
142 */
143 conf->connected = false;
145 return (-1);
146 }
148 return (0);
149 } /* mqtt_publish_message */
151 static int mqtt_format_metric_value (char *buf, size_t buf_len,
152 const data_set_t *data_set, const value_list_t *vl, int ds_num)
153 {
154 gauge_t *rates = NULL;
155 gauge_t *value = NULL;
156 size_t metric_value_len;
157 int status = 0;
159 memset (buf, 0, buf_len);
161 if (data_set->ds[ds_num].type == DS_TYPE_GAUGE)
162 value = &vl->values[ds_num].gauge;
163 else {
164 rates = uc_get_rate (data_set, vl);
165 value = &rates[ds_num];
166 }
168 metric_value_len = ssnprintf (buf, buf_len, "%f", *value);
170 if (metric_value_len >= buf_len)
171 return (-ENOMEM);
173 if (rates)
174 sfree (rates);
176 return (status);
177 } /* mqtt_format_metric_value */
179 static int mqtt_format_message_topic (char *buf, size_t buf_len,
180 char const *prefix, const value_list_t *vl, const char *ds_name)
181 {
182 size_t topic_buf_len;
184 memset (buf, 0, buf_len);
186 /*
187 MQTT message topic format:
188 [<prefix>/]<hostname>/<plugin>/<plugin instance>/<type>/<type instance>/<ds>/
189 */
190 topic_buf_len = (size_t) ssnprintf (buf, buf_len,
191 "%s/%s/%s/%s/%s/%s/%s",
192 prefix,
193 vl->host,
194 vl->plugin,
195 vl->plugin_instance[0] != '\0' ? vl->plugin_instance : "(null)",
196 vl->type,
197 vl->type_instance[0] != '\0' ? vl->type_instance : "(null)",
198 ds_name);
200 if (topic_buf_len >= buf_len)
201 {
202 ERROR ("mqtt_format_message_topic: topic buffer too small: "
203 "Need %zu bytes.", topic_buf_len + 1);
204 return (-ENOMEM);
205 }
207 return (0);
208 } /* mqtt_format_message_topic */
210 static int mqtt_format_payload (char *buf, size_t buf_len,
211 const data_set_t *data_set, const value_list_t *vl, int ds_num)
212 {
213 char metric_path[10 * DATA_MAX_NAME_LEN];
214 char metric_value[512];
215 size_t payload_buf_len;
216 int status = 0;
218 memset (buf, 0, buf_len);
220 ssnprintf (metric_path, sizeof (metric_path),
221 "%s.%s%s%s.%s%s%s%s%s",
222 vl->host,
223 vl->plugin,
224 vl->plugin_instance[0] != '\0' ? "." : "",
225 vl->plugin_instance[0] != '\0' ? vl->plugin_instance : "",
226 vl->type,
227 vl->type_instance[0] != '\0' ? "." : "",
228 vl->type_instance[0] != '\0' ? vl->type_instance : "",
229 strcmp(data_set->ds[ds_num].name, "value") != 0 ? "." : "",
230 strcmp(data_set->ds[ds_num].name, "value") != 0 ?
231 data_set->ds[ds_num].name : "");
233 status = mqtt_format_metric_value (metric_value,
234 sizeof (metric_value),
235 data_set,
236 vl,
237 ds_num);
239 if (status != 0)
240 {
241 ERROR ("mqtt_format_payload: error with mqtt_format_metric_value");
242 return (status);
243 }
245 payload_buf_len = (size_t) ssnprintf (buf, buf_len,
246 "%s %s %u",
247 metric_path,
248 metric_value,
249 (unsigned int) CDTIME_T_TO_TIME_T (vl->time));
251 if (payload_buf_len >= buf_len)
252 {
253 ERROR ("mqtt_format_payload: payload buffer too small: "
254 "Need %zu bytes.", payload_buf_len + 1);
255 return (-ENOMEM);
256 }
258 return (status);
259 } /* mqtt_format_payload */
261 static int mqtt_write (const data_set_t *data_set, const value_list_t *vl,
262 user_data_t *user_data)
263 {
264 struct mqtt_client_conf *conf;
265 char msg_topic[MQTT_MAX_TOPIC_SIZE];
266 char msg_payload[MQTT_MAX_MESSAGE_SIZE];
267 int status = 0;
268 int i;
270 if (user_data == NULL)
271 return (EINVAL);
273 conf = user_data->data;
275 if (!conf->connected)
276 {
277 status = mqtt_reconnect_broker (conf);
279 if (status != 0) {
280 ERROR ("plugin mqtt: unable to reconnect to broker");
281 return (status);
282 }
283 }
285 for (i = 0; i < data_set->ds_num; i++)
286 {
287 status = mqtt_format_message_topic (msg_topic, sizeof (msg_topic),
288 conf->topic_prefix, vl, data_set->ds[i].name);
289 if (status != 0)
290 {
291 ERROR ("plugin mqtt: error with mqtt_format_message_topic");
292 return (status);
293 }
295 status = mqtt_format_payload (msg_payload,
296 sizeof (msg_payload),
297 data_set,
298 vl,
299 i);
301 if (status != 0)
302 {
303 ERROR ("mqtt_write: error with mqtt_format_payload");
304 return (status);
305 }
307 status = mqtt_publish_message (conf,
308 msg_topic,
309 msg_payload,
310 sizeof (msg_payload));
311 if (status != 0)
312 {
313 ERROR ("plugin mqtt: unable to publish message");
314 return (status);
315 }
317 DEBUG ("\x1B[36m[debug]\x1B[0m\x1B[37m mqtt_write[%02X]\x1B[0m "
318 "published message: topic=%s payload=%s",
319 (unsigned)pthread_self(),
320 msg_topic,
321 msg_payload);
322 }
324 return (status);
325 } /* mqtt_write */
327 static int mqtt_config (oconfig_item_t *ci)
328 {
329 struct mqtt_client_conf *conf;
330 user_data_t user_data;
331 char errbuf[1024];
332 int status;
334 DEBUG ("\x1B[36m[debug]\x1B[0m\x1B[37m mqtt_config[%02X]\x1B[0m ",
335 (unsigned)pthread_self());
337 conf = malloc (sizeof (*conf));
338 if (conf == NULL)
339 {
340 ERROR ("write_mqtt plugin: malloc failed.");
341 return (-1);
342 }
344 memset (conf, 0, sizeof (*conf));
346 conf->connected = false;
347 conf->host = MQTT_DEFAULT_HOST;
348 conf->port = MQTT_DEFAULT_PORT;
349 conf->client_id = MQTT_DEFAULT_CLIENT_ID;
350 conf->topic_prefix = MQTT_DEFAULT_TOPIC_PREFIX;
351 C_COMPLAIN_INIT (&conf->complaint_cantpublish);
353 memset (&user_data, 0, sizeof (user_data));
354 user_data.data = conf;
356 conf->mosq = mosquitto_new (conf->client_id, /* user data = */ conf);
357 if (conf->mosq == NULL)
358 {
359 ERROR ("mqtt plugin: mosquitto_new failed");
360 free (conf);
361 return (-1);
362 }
364 status = mosquitto_connect (conf->mosq, conf->host, conf->port,
365 /* keepalive = */ 10, /* clean session = */ 1);
366 if (status != MOSQ_ERR_SUCCESS) {
367 ERROR ("mqtt_config: mosquitto_connect failed: %s",
368 (status == MOSQ_ERR_ERRNO ?
369 sstrerror(errno, errbuf, sizeof (errbuf)) :
370 mosquitto_strerror (status)));
371 return (-1);
372 }
374 DEBUG ("mqtt plugin: successfully connected to broker \"%s:%d\"",
375 conf->host, conf->port);
377 conf->connected = true;
379 plugin_register_write ("mqtt", mqtt_write, &user_data);
381 return (0);
382 } /* mqtt_config */
384 static int mqtt_init (void)
385 {
386 mosquitto_lib_init();
388 return (0);
389 } /* mqtt_init */
391 void module_register (void)
392 {
393 plugin_register_complex_config ("mqtt", mqtt_config);
394 plugin_register_init ("mqtt", mqtt_init);
395 } /* void module_register */
397 /* vim: set sw=4 sts=4 et fdm=marker : */