--- /dev/null
+/**
+ * collectd - src/mqtt.c
+ * Copyright (C) 2014 Marc Falzon <marc at baha dot mu>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ **/
+
+// Reference: http://mosquitto.org/api/files/mosquitto-h.html
+
+
+#include "collectd.h"
+#include "common.h"
+#include "plugin.h"
+#include "utils_cache.h"
+#include "utils_complain.h"
+
+#include <pthread.h>
+
+#include <mosquitto.h>
+
+#define MQTT_MAX_TOPIC_SIZE 1024
+#define MQTT_MAX_MESSAGE_SIZE MQTT_MAX_TOPIC_SIZE + 1024
+#define MQTT_DEFAULT_HOST "localhost"
+#define MQTT_DEFAULT_PORT 1883
+#define MQTT_DEFAULT_CLIENT_ID "collectd"
+#define MQTT_DEFAULT_TOPIC_PREFIX "collectd"
+
+/*
+ * Data types
+ */
+struct mqtt_client_conf
+{
+ struct mosquitto *mosq;
+ bool connected;
+ char *host;
+ int port;
+ char *client_id;
+ char *topic_prefix;
+ c_complain_t complaint_cantpublish;
+ pthread_mutex_t lock;
+};
+
+/*
+ * Functions
+ */
+static int mqtt_reconnect_broker (struct mqtt_client_conf *conf)
+{
+ int status;
+
+ if (conf->connected)
+ return (0);
+
+ pthread_mutex_lock (&conf->lock);
+
+ status = mosquitto_reconnect (conf->mosq);
+
+ if (status != MOSQ_ERR_SUCCESS) {
+ ERROR ("mqtt_connect_broker: mosquitto_connect failed: %s",
+ (status == MOSQ_ERR_ERRNO ?
+ strerror(errno) : mosquitto_strerror (status)));
+ pthread_mutex_unlock (&conf->lock);
+ return (-1);
+ }
+
+ conf->connected = true;
+
+ c_release (LOG_INFO,
+ &conf->complaint_cantpublish,
+ "mqtt plugin: successfully reconnected to broker \"%s:%d\"",
+ conf->host, conf->port);
+
+ pthread_mutex_unlock (&conf->lock);
+
+ return (0);
+} /* mqtt_reconnect_broker */
+
+static int mqtt_publish_message (struct mqtt_client_conf *conf, char *topic,
+ char *payload, size_t payload_len)
+{
+ char errbuf[1024];
+ int status;
+
+ status = mosquitto_publish(conf->mosq,
+ /* message id */ NULL,
+ topic,
+ (int) payload_len,
+ payload,
+ /* qos */ 0,
+ /* retain */ false);
+
+ if (status != MOSQ_ERR_SUCCESS)
+ {
+ c_complain (LOG_ERR,
+ &conf->complaint_cantpublish,
+ "plugin mqtt: mosquitto_publish failed: %s",
+ status == MOSQ_ERR_ERRNO ?
+ sstrerror(errno, errbuf, sizeof (errbuf)) :
+ mosquitto_strerror(status));
+ /*
+ Mark our connection "down" regardless of the error as a safety measure;
+ we will try to reconnect the next time we have to publish a message
+ */
+ conf->connected = false;
+
+ return (-1);
+ }
+
+ return (0);
+} /* mqtt_publish_message */
+
+static int mqtt_format_metric_value (char *buf, size_t buf_len,
+ const data_set_t *data_set, const value_list_t *vl, int ds_num)
+{
+ gauge_t *rates = NULL;
+ gauge_t *value = NULL;
+ size_t metric_value_len;
+ int status = 0;
+
+ memset (buf, 0, buf_len);
+
+ if (data_set->ds[ds_num].type == DS_TYPE_GAUGE)
+ value = &vl->values[ds_num].gauge;
+ else {
+ rates = uc_get_rate (data_set, vl);
+ value = &rates[ds_num];
+ }
+
+ metric_value_len = ssnprintf (buf, buf_len, "%f", *value);
+
+ if (metric_value_len >= buf_len)
+ return (-ENOMEM);
+
+ if (rates)
+ sfree (rates);
+
+ return (status);
+} /* mqtt_format_metric_value */
+
+static int mqtt_format_message_topic (char *buf, size_t buf_len,
+ char const *prefix, const value_list_t *vl, const char *ds_name)
+{
+ size_t topic_buf_len;
+
+ memset (buf, 0, buf_len);
+
+ /*
+ MQTT message topic format:
+ [<prefix>/]<hostname>/<plugin>/<plugin instance>/<type>/<type instance>/<ds>/
+ */
+ topic_buf_len = (size_t) ssnprintf (buf, buf_len,
+ "%s/%s/%s/%s/%s/%s/%s",
+ prefix,
+ vl->host,
+ vl->plugin,
+ vl->plugin_instance[0] != '\0' ? vl->plugin_instance : "(null)",
+ vl->type,
+ vl->type_instance[0] != '\0' ? vl->type_instance : "(null)",
+ ds_name);
+
+ if (topic_buf_len >= buf_len)
+ {
+ ERROR ("mqtt_format_message_topic: topic buffer too small: "
+ "Need %zu bytes.", topic_buf_len + 1);
+ return (-ENOMEM);
+ }
+
+ return (0);
+} /* mqtt_format_message_topic */
+
+static int mqtt_format_payload (char *buf, size_t buf_len,
+ const data_set_t *data_set, const value_list_t *vl, int ds_num)
+{
+ char metric_path[10 * DATA_MAX_NAME_LEN];
+ char metric_value[512];
+ size_t payload_buf_len;
+ int status = 0;
+
+ memset (buf, 0, buf_len);
+
+ ssnprintf (metric_path, sizeof (metric_path),
+ "%s.%s%s%s.%s%s%s%s%s",
+ vl->host,
+ vl->plugin,
+ vl->plugin_instance[0] != '\0' ? "." : "",
+ vl->plugin_instance[0] != '\0' ? vl->plugin_instance : "",
+ vl->type,
+ vl->type_instance[0] != '\0' ? "." : "",
+ vl->type_instance[0] != '\0' ? vl->type_instance : "",
+ strcmp(data_set->ds[ds_num].name, "value") != 0 ? "." : "",
+ strcmp(data_set->ds[ds_num].name, "value") != 0 ?
+ data_set->ds[ds_num].name : "");
+
+ status = mqtt_format_metric_value (metric_value,
+ sizeof (metric_value),
+ data_set,
+ vl,
+ ds_num);
+
+ if (status != 0)
+ {
+ ERROR ("mqtt_format_payload: error with mqtt_format_metric_value");
+ return (status);
+ }
+
+ payload_buf_len = (size_t) ssnprintf (buf, buf_len,
+ "%s %s %u",
+ metric_path,
+ metric_value,
+ (unsigned int) CDTIME_T_TO_TIME_T (vl->time));
+
+ if (payload_buf_len >= buf_len)
+ {
+ ERROR ("mqtt_format_payload: payload buffer too small: "
+ "Need %zu bytes.", payload_buf_len + 1);
+ return (-ENOMEM);
+ }
+
+ return (status);
+} /* mqtt_format_payload */
+
+static int mqtt_write (const data_set_t *data_set, const value_list_t *vl,
+ user_data_t *user_data)
+{
+ struct mqtt_client_conf *conf;
+ char msg_topic[MQTT_MAX_TOPIC_SIZE];
+ char msg_payload[MQTT_MAX_MESSAGE_SIZE];
+ int status = 0;
+ int i;
+
+ if (user_data == NULL)
+ return (EINVAL);
+
+ conf = user_data->data;
+
+ if (!conf->connected)
+ {
+ status = mqtt_reconnect_broker (conf);
+
+ if (status != 0) {
+ ERROR ("plugin mqtt: unable to reconnect to broker");
+ return (status);
+ }
+ }
+
+ for (i = 0; i < data_set->ds_num; i++)
+ {
+ status = mqtt_format_message_topic (msg_topic, sizeof (msg_topic),
+ conf->topic_prefix, vl, data_set->ds[i].name);
+ if (status != 0)
+ {
+ ERROR ("plugin mqtt: error with mqtt_format_message_topic");
+ return (status);
+ }
+
+ status = mqtt_format_payload (msg_payload,
+ sizeof (msg_payload),
+ data_set,
+ vl,
+ i);
+
+ if (status != 0)
+ {
+ ERROR ("mqtt_write: error with mqtt_format_payload");
+ return (status);
+ }
+
+ status = mqtt_publish_message (conf,
+ msg_topic,
+ msg_payload,
+ sizeof (msg_payload));
+ if (status != 0)
+ {
+ ERROR ("plugin mqtt: unable to publish message");
+ return (status);
+ }
+
+ DEBUG ("\x1B[36m[debug]\x1B[0m\x1B[37m mqtt_write[%02X]\x1B[0m "
+ "published message: topic=%s payload=%s",
+ (unsigned)pthread_self(),
+ msg_topic,
+ msg_payload);
+ }
+
+ return (status);
+} /* mqtt_write */
+
+static int mqtt_config (oconfig_item_t *ci)
+{
+ struct mqtt_client_conf *conf;
+ user_data_t user_data;
+ char errbuf[1024];
+ int status;
+
+ DEBUG ("\x1B[36m[debug]\x1B[0m\x1B[37m mqtt_config[%02X]\x1B[0m ",
+ (unsigned)pthread_self());
+
+ conf = malloc (sizeof (*conf));
+ if (conf == NULL)
+ {
+ ERROR ("write_mqtt plugin: malloc failed.");
+ return (-1);
+ }
+
+ memset (conf, 0, sizeof (*conf));
+
+ conf->connected = false;
+ conf->host = MQTT_DEFAULT_HOST;
+ conf->port = MQTT_DEFAULT_PORT;
+ conf->client_id = MQTT_DEFAULT_CLIENT_ID;
+ conf->topic_prefix = MQTT_DEFAULT_TOPIC_PREFIX;
+ C_COMPLAIN_INIT (&conf->complaint_cantpublish);
+
+ memset (&user_data, 0, sizeof (user_data));
+ user_data.data = conf;
+
+ if ((conf->mosq = mosquitto_new (conf->client_id, true, NULL)) == NULL) {
+ ERROR ("mqtt_config: mosquitto_new failed");
+ return (-1);
+ }
+
+ status = mosquitto_connect (conf->mosq, conf->host, conf->port, 10);
+
+ if (status != MOSQ_ERR_SUCCESS) {
+ ERROR ("mqtt_config: mosquitto_connect failed: %s",
+ (status == MOSQ_ERR_ERRNO ?
+ sstrerror(errno, errbuf, sizeof (errbuf)) :
+ mosquitto_strerror (status)));
+ return (-1);
+ }
+
+ DEBUG ("mqtt plugin: successfully connected to broker \"%s:%d\"",
+ conf->host, conf->port);
+
+ conf->connected = true;
+
+ plugin_register_write ("mqtt", mqtt_write, &user_data);
+
+ return (0);
+} /* mqtt_config */
+
+static int mqtt_init (void)
+{
+ mosquitto_lib_init();
+
+ return (0);
+} /* mqtt_init */
+
+void module_register (void)
+{
+ plugin_register_complex_config ("mqtt", mqtt_config);
+ plugin_register_init ("mqtt", mqtt_init);
+} /* void module_register */
+
+/* vim: set sw=4 sts=4 et fdm=marker : */
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