Initial import

diff --git a/README.md b/README.md
index 0cdb41382c18e867e9fec6b0cb4cd08f299806e0..ef2b4deb0d7af2f83afd8067674ebaa9d66488a6 100644 (file)
--- a/README.md
+++ b/README.md
@@ -1,4 +1,38 @@
 collectd-mqtt
 =============
 
-Draft MQTT plugin for collectd
+This is my unfinished attempt to produce a MQTT write plugin for [collectd][0]
+using the [Mosquitto][1] library. Due to a lack of time I never managed to get
+the project to move forward.
+
+I'm not a professional developer – even less C developer, so expect this code to
+be bad. Probably really bad. You've been warned.
+
+License
+-------
+
+The MIT License (MIT)
+
+Copyright (c) 2014 Marc Falzon <marc@baha.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.
+
+
+[0]: https://collectd.org/
+[1]: http://mosquitto.org/

diff --git a/mqtt.c b/mqtt.c
new file mode 100644 (file)
index 0000000..3bed0a5
--- /dev/null
+++ b/mqtt.c
@@ -0,0 +1,370 @@
+/**
+ * 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 : */

diff --git a/mqtt.conf b/mqtt.conf
new file mode 100644 (file)
index 0000000..eae25bd
--- /dev/null
+++ b/mqtt.conf
@@ -0,0 +1,6 @@
+<Plugin mqtt>
+    <Publish "local">
+        Host "localhost"
+        TopicPrefix "collectd"
+    </Publish>
+</Plugin>