X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Fwrite_http.c;h=c1b3f0b0c7c7cc25cb4455d9b9a5c128cbc2dfbe;hb=da11ce02eb202b3e01d3e2d1b40f248a84430973;hp=d8d8c34e60f9fd0e1f2dcdb709ea63d65e61766d;hpb=92f3b751cce6466fc23175e75fe3b8a3b8f23cff;p=collectd.git

diff --git a/src/write_http.c b/src/write_http.c
index d8d8c34e..87e518b6 100644
--- a/src/write_http.c
+++ b/src/write_http.c
@@ -25,852 +25,845 @@
 
 #include "collectd.h"
 
-#include "plugin.h"
 #include "common.h"
+#include "plugin.h"
 #include "utils_format_json.h"
 #include "utils_format_kairosdb.h"
 
 #include <curl/curl.h>
 
 #ifndef WRITE_HTTP_DEFAULT_BUFFER_SIZE
-# define WRITE_HTTP_DEFAULT_BUFFER_SIZE 4096
+#define WRITE_HTTP_DEFAULT_BUFFER_SIZE 4096
+#endif
+
+#ifndef WRITE_HTTP_DEFAULT_PREFIX
+#define WRITE_HTTP_DEFAULT_PREFIX "collectd"
 #endif
 
 /*
  * Private variables
  */
-struct wh_callback_s
-{
-        char *name;
-
-        char *location;
-        char *user;
-        char *pass;
-        char *credentials;
-        _Bool verify_peer;
-        _Bool verify_host;
-        char *cacert;
-        char *capath;
-        char *clientkey;
-        char *clientcert;
-        char *clientkeypass;
-        long sslversion;
-        _Bool store_rates;
-        _Bool log_http_error;
-        int   low_speed_limit;
-        time_t low_speed_time;
-        int timeout;
-
-#define WH_FORMAT_COMMAND  0
-#define WH_FORMAT_JSON     1
+struct wh_callback_s {
+  char *name;
+
+  char *location;
+  char *user;
+  char *pass;
+  char *credentials;
+  _Bool verify_peer;
+  _Bool verify_host;
+  char *cacert;
+  char *capath;
+  char *clientkey;
+  char *clientcert;
+  char *clientkeypass;
+  long sslversion;
+  _Bool store_rates;
+  _Bool log_http_error;
+  int low_speed_limit;
+  time_t low_speed_time;
+  int timeout;
+
+#define WH_FORMAT_COMMAND 0
+#define WH_FORMAT_JSON 1
 #define WH_FORMAT_KAIROSDB 2
-        int format;
-        _Bool send_metrics;
-        _Bool send_notifications;
+  int format;
+  _Bool send_metrics;
+  _Bool send_notifications;
+
+  CURL *curl;
+  struct curl_slist *headers;
+  char curl_errbuf[CURL_ERROR_SIZE];
 
-        CURL *curl;
-        struct curl_slist *headers;
-        char curl_errbuf[CURL_ERROR_SIZE];
+  char *send_buffer;
+  size_t send_buffer_size;
+  size_t send_buffer_free;
+  size_t send_buffer_fill;
+  cdtime_t send_buffer_init_time;
 
-        char  *send_buffer;
-        size_t send_buffer_size;
-        size_t send_buffer_free;
-        size_t send_buffer_fill;
-        cdtime_t send_buffer_init_time;
+  pthread_mutex_t send_lock;
 
-        pthread_mutex_t send_lock;
+  int data_ttl;
+  char *metrics_prefix;
 };
 typedef struct wh_callback_s wh_callback_t;
 
-static void wh_log_http_error (wh_callback_t *cb)
-{
-        if (!cb->log_http_error)
-                return;
+static char **http_attrs;
+static size_t http_attrs_num;
+
+static void wh_log_http_error(wh_callback_t *cb) {
+  if (!cb->log_http_error)
+    return;
 
-        long http_code = 0;
+  long http_code = 0;
 
-        curl_easy_getinfo (cb->curl, CURLINFO_RESPONSE_CODE, &http_code);
+  curl_easy_getinfo(cb->curl, CURLINFO_RESPONSE_CODE, &http_code);
 
-        if (http_code != 200)
-                INFO ("write_http plugin: HTTP Error code: %lu", http_code);
+  if (http_code != 200)
+    INFO("write_http plugin: HTTP Error code: %lu", http_code);
 }
 
-static void wh_reset_buffer (wh_callback_t *cb)  /* {{{ */
+static void wh_reset_buffer(wh_callback_t *cb) /* {{{ */
 {
-        if ((cb == NULL) || (cb->send_buffer == NULL))
-                return;
-
-        memset (cb->send_buffer, 0, cb->send_buffer_size);
-        cb->send_buffer_free = cb->send_buffer_size;
-        cb->send_buffer_fill = 0;
-        cb->send_buffer_init_time = cdtime ();
-
-        if (cb->format == WH_FORMAT_JSON || cb->format == WH_FORMAT_KAIROSDB)
-        {
-                format_json_initialize (cb->send_buffer,
-                                &cb->send_buffer_fill,
-                                &cb->send_buffer_free);
-        }
+  if ((cb == NULL) || (cb->send_buffer == NULL))
+    return;
+
+  memset(cb->send_buffer, 0, cb->send_buffer_size);
+  cb->send_buffer_free = cb->send_buffer_size;
+  cb->send_buffer_fill = 0;
+  cb->send_buffer_init_time = cdtime();
+
+  if (cb->format == WH_FORMAT_JSON || cb->format == WH_FORMAT_KAIROSDB) {
+    format_json_initialize(cb->send_buffer, &cb->send_buffer_fill,
+                           &cb->send_buffer_free);
+  }
 } /* }}} wh_reset_buffer */
 
 /* must hold cb->send_lock when calling */
-static int wh_post_nolock (wh_callback_t *cb, char const *data) /* {{{ */
+static int wh_post_nolock(wh_callback_t *cb, char const *data) /* {{{ */
 {
-        int status = 0;
+  int status = 0;
 
-        curl_easy_setopt (cb->curl, CURLOPT_POSTFIELDS, data);
-        status = curl_easy_perform (cb->curl);
+  curl_easy_setopt(cb->curl, CURLOPT_URL, cb->location);
+  curl_easy_setopt(cb->curl, CURLOPT_POSTFIELDS, data);
+  status = curl_easy_perform(cb->curl);
 
-        wh_log_http_error (cb);
+  wh_log_http_error(cb);
 
-        if (status != CURLE_OK)
-        {
-                ERROR ("write_http plugin: curl_easy_perform failed with "
-                                "status %i: %s",
-                                status, cb->curl_errbuf);
-        }
-        return (status);
+  if (status != CURLE_OK) {
+    ERROR("write_http plugin: curl_easy_perform failed with "
+          "status %i: %s",
+          status, cb->curl_errbuf);
+  }
+  return status;
 } /* }}} wh_post_nolock */
 
-static int wh_callback_init (wh_callback_t *cb) /* {{{ */
+static int wh_callback_init(wh_callback_t *cb) /* {{{ */
 {
-        if (cb->curl != NULL)
-                return (0);
-
-        cb->curl = curl_easy_init ();
-        if (cb->curl == NULL)
-        {
-                ERROR ("curl plugin: curl_easy_init failed.");
-                return (-1);
-        }
-
-        if (cb->low_speed_limit > 0 && cb->low_speed_time > 0)
-        {
-                curl_easy_setopt (cb->curl, CURLOPT_LOW_SPEED_LIMIT,
-                                  (long) (cb->low_speed_limit * cb->low_speed_time));
-                curl_easy_setopt (cb->curl, CURLOPT_LOW_SPEED_TIME,
-                                  (long) cb->low_speed_time);
-        }
+  if (cb->curl != NULL)
+    return 0;
+
+  cb->curl = curl_easy_init();
+  if (cb->curl == NULL) {
+    ERROR("curl plugin: curl_easy_init failed.");
+    return -1;
+  }
+
+  if (cb->low_speed_limit > 0 && cb->low_speed_time > 0) {
+    curl_easy_setopt(cb->curl, CURLOPT_LOW_SPEED_LIMIT,
+                     (long)(cb->low_speed_limit * cb->low_speed_time));
+    curl_easy_setopt(cb->curl, CURLOPT_LOW_SPEED_TIME,
+                     (long)cb->low_speed_time);
+  }
 
 #ifdef HAVE_CURLOPT_TIMEOUT_MS
-        if (cb->timeout > 0)
-                curl_easy_setopt (cb->curl, CURLOPT_TIMEOUT_MS, (long) cb->timeout);
+  if (cb->timeout > 0)
+    curl_easy_setopt(cb->curl, CURLOPT_TIMEOUT_MS, (long)cb->timeout);
 #endif
 
-        curl_easy_setopt (cb->curl, CURLOPT_NOSIGNAL, 1L);
-        curl_easy_setopt (cb->curl, CURLOPT_USERAGENT, COLLECTD_USERAGENT);
+  curl_easy_setopt(cb->curl, CURLOPT_NOSIGNAL, 1L);
+  curl_easy_setopt(cb->curl, CURLOPT_USERAGENT, COLLECTD_USERAGENT);
 
-        cb->headers = curl_slist_append (cb->headers, "Accept:  */*");
-        if (cb->format == WH_FORMAT_JSON || cb->format == WH_FORMAT_KAIROSDB)
-                cb->headers = curl_slist_append (cb->headers, "Content-Type: application/json");
-        else
-                cb->headers = curl_slist_append (cb->headers, "Content-Type: text/plain");
-        cb->headers = curl_slist_append (cb->headers, "Expect:");
-        curl_easy_setopt (cb->curl, CURLOPT_HTTPHEADER, cb->headers);
+  cb->headers = curl_slist_append(cb->headers, "Accept:  */*");
+  if (cb->format == WH_FORMAT_JSON || cb->format == WH_FORMAT_KAIROSDB)
+    cb->headers =
+        curl_slist_append(cb->headers, "Content-Type: application/json");
+  else
+    cb->headers = curl_slist_append(cb->headers, "Content-Type: text/plain");
+  cb->headers = curl_slist_append(cb->headers, "Expect:");
+  curl_easy_setopt(cb->curl, CURLOPT_HTTPHEADER, cb->headers);
 
-        curl_easy_setopt (cb->curl, CURLOPT_ERRORBUFFER, cb->curl_errbuf);
-        curl_easy_setopt (cb->curl, CURLOPT_URL, cb->location);
-        curl_easy_setopt (cb->curl, CURLOPT_FOLLOWLOCATION, 1L);
-        curl_easy_setopt (cb->curl, CURLOPT_MAXREDIRS, 50L);
+  curl_easy_setopt(cb->curl, CURLOPT_ERRORBUFFER, cb->curl_errbuf);
+  curl_easy_setopt(cb->curl, CURLOPT_FOLLOWLOCATION, 1L);
+  curl_easy_setopt(cb->curl, CURLOPT_MAXREDIRS, 50L);
 
-        if (cb->user != NULL)
-        {
+  if (cb->user != NULL) {
 #ifdef HAVE_CURLOPT_USERNAME
-                curl_easy_setopt (cb->curl, CURLOPT_USERNAME, cb->user);
-                curl_easy_setopt (cb->curl, CURLOPT_PASSWORD,
-                        (cb->pass == NULL) ? "" : cb->pass);
+    curl_easy_setopt(cb->curl, CURLOPT_USERNAME, cb->user);
+    curl_easy_setopt(cb->curl, CURLOPT_PASSWORD,
+                     (cb->pass == NULL) ? "" : cb->pass);
 #else
-                size_t credentials_size;
-
-                credentials_size = strlen (cb->user) + 2;
-                if (cb->pass != NULL)
-                        credentials_size += strlen (cb->pass);
-
-                cb->credentials = malloc (credentials_size);
-                if (cb->credentials == NULL)
-                {
-                        ERROR ("curl plugin: malloc failed.");
-                        return (-1);
-                }
-
-                ssnprintf (cb->credentials, credentials_size, "%s:%s",
-                                cb->user, (cb->pass == NULL) ? "" : cb->pass);
-                curl_easy_setopt (cb->curl, CURLOPT_USERPWD, cb->credentials);
+    size_t credentials_size;
+
+    credentials_size = strlen(cb->user) + 2;
+    if (cb->pass != NULL)
+      credentials_size += strlen(cb->pass);
+
+    cb->credentials = malloc(credentials_size);
+    if (cb->credentials == NULL) {
+      ERROR("curl plugin: malloc failed.");
+      return -1;
+    }
+
+    snprintf(cb->credentials, credentials_size, "%s:%s", cb->user,
+             (cb->pass == NULL) ? "" : cb->pass);
+    curl_easy_setopt(cb->curl, CURLOPT_USERPWD, cb->credentials);
 #endif
-                curl_easy_setopt (cb->curl, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
-        }
-
-        curl_easy_setopt (cb->curl, CURLOPT_SSL_VERIFYPEER, (long) cb->verify_peer);
-        curl_easy_setopt (cb->curl, CURLOPT_SSL_VERIFYHOST,
-                        cb->verify_host ? 2L : 0L);
-        curl_easy_setopt (cb->curl, CURLOPT_SSLVERSION, cb->sslversion);
-        if (cb->cacert != NULL)
-                curl_easy_setopt (cb->curl, CURLOPT_CAINFO, cb->cacert);
-        if (cb->capath != NULL)
-                curl_easy_setopt (cb->curl, CURLOPT_CAPATH, cb->capath);
-
-        if (cb->clientkey != NULL && cb->clientcert != NULL)
-        {
-            curl_easy_setopt (cb->curl, CURLOPT_SSLKEY, cb->clientkey);
-            curl_easy_setopt (cb->curl, CURLOPT_SSLCERT, cb->clientcert);
-
-            if (cb->clientkeypass != NULL)
-                curl_easy_setopt (cb->curl, CURLOPT_SSLKEYPASSWD, cb->clientkeypass);
-        }
-
-        wh_reset_buffer (cb);
-
-        return (0);
+    curl_easy_setopt(cb->curl, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
+  }
+
+  curl_easy_setopt(cb->curl, CURLOPT_SSL_VERIFYPEER, (long)cb->verify_peer);
+  curl_easy_setopt(cb->curl, CURLOPT_SSL_VERIFYHOST, cb->verify_host ? 2L : 0L);
+  curl_easy_setopt(cb->curl, CURLOPT_SSLVERSION, cb->sslversion);
+  if (cb->cacert != NULL)
+    curl_easy_setopt(cb->curl, CURLOPT_CAINFO, cb->cacert);
+  if (cb->capath != NULL)
+    curl_easy_setopt(cb->curl, CURLOPT_CAPATH, cb->capath);
+
+  if (cb->clientkey != NULL && cb->clientcert != NULL) {
+    curl_easy_setopt(cb->curl, CURLOPT_SSLKEY, cb->clientkey);
+    curl_easy_setopt(cb->curl, CURLOPT_SSLCERT, cb->clientcert);
+
+    if (cb->clientkeypass != NULL)
+      curl_easy_setopt(cb->curl, CURLOPT_SSLKEYPASSWD, cb->clientkeypass);
+  }
+
+  wh_reset_buffer(cb);
+
+  return 0;
 } /* }}} int wh_callback_init */
 
-static int wh_flush_nolock (cdtime_t timeout, wh_callback_t *cb) /* {{{ */
+static int wh_flush_nolock(cdtime_t timeout, wh_callback_t *cb) /* {{{ */
 {
-        int status;
-
-        DEBUG ("write_http plugin: wh_flush_nolock: timeout = %.3f; "
-                        "send_buffer_fill = %zu;",
-                        CDTIME_T_TO_DOUBLE (timeout),
-                        cb->send_buffer_fill);
-
-        /* timeout == 0  => flush unconditionally */
-        if (timeout > 0)
-        {
-                cdtime_t now;
-
-                now = cdtime ();
-                if ((cb->send_buffer_init_time + timeout) > now)
-                        return (0);
-        }
-
-        if (cb->format == WH_FORMAT_COMMAND)
-        {
-                if (cb->send_buffer_fill == 0)
-                {
-                        cb->send_buffer_init_time = cdtime ();
-                        return (0);
-                }
-
-                status = wh_post_nolock (cb, cb->send_buffer);
-                wh_reset_buffer (cb);
-        }
-        else if (cb->format == WH_FORMAT_JSON || cb->format == WH_FORMAT_KAIROSDB)
-        {
-                if (cb->send_buffer_fill <= 2)
-                {
-                        cb->send_buffer_init_time = cdtime ();
-                        return (0);
-                }
-
-                status = format_json_finalize (cb->send_buffer,
-                                &cb->send_buffer_fill,
-                                &cb->send_buffer_free);
-                if (status != 0)
-                {
-                        ERROR ("write_http: wh_flush_nolock: "
-                                        "format_json_finalize failed.");
-                        wh_reset_buffer (cb);
-                        return (status);
-                }
-
-                status = wh_post_nolock (cb, cb->send_buffer);
-                wh_reset_buffer (cb);
-        }
-        else
-        {
-                ERROR ("write_http: wh_flush_nolock: "
-                                "Unknown format: %i",
-                                cb->format);
-                return (-1);
-        }
-
-        return (status);
+  int status;
+
+  DEBUG("write_http plugin: wh_flush_nolock: timeout = %.3f; "
+        "send_buffer_fill = %zu;",
+        CDTIME_T_TO_DOUBLE(timeout), cb->send_buffer_fill);
+
+  /* timeout == 0  => flush unconditionally */
+  if (timeout > 0) {
+    cdtime_t now;
+
+    now = cdtime();
+    if ((cb->send_buffer_init_time + timeout) > now)
+      return 0;
+  }
+
+  if (cb->format == WH_FORMAT_COMMAND) {
+    if (cb->send_buffer_fill == 0) {
+      cb->send_buffer_init_time = cdtime();
+      return 0;
+    }
+
+    status = wh_post_nolock(cb, cb->send_buffer);
+    wh_reset_buffer(cb);
+  } else if (cb->format == WH_FORMAT_JSON || cb->format == WH_FORMAT_KAIROSDB) {
+    if (cb->send_buffer_fill <= 2) {
+      cb->send_buffer_init_time = cdtime();
+      return 0;
+    }
+
+    status = format_json_finalize(cb->send_buffer, &cb->send_buffer_fill,
+                                  &cb->send_buffer_free);
+    if (status != 0) {
+      ERROR("write_http: wh_flush_nolock: "
+            "format_json_finalize failed.");
+      wh_reset_buffer(cb);
+      return status;
+    }
+
+    status = wh_post_nolock(cb, cb->send_buffer);
+    wh_reset_buffer(cb);
+  } else {
+    ERROR("write_http: wh_flush_nolock: "
+          "Unknown format: %i",
+          cb->format);
+    return -1;
+  }
+
+  return status;
 } /* }}} wh_flush_nolock */
 
-static int wh_flush (cdtime_t timeout, /* {{{ */
-                const char *identifier __attribute__((unused)),
-                user_data_t *user_data)
-{
-        wh_callback_t *cb;
-        int status;
+static int wh_flush(cdtime_t timeout, /* {{{ */
+                    const char *identifier __attribute__((unused)),
+                    user_data_t *user_data) {
+  wh_callback_t *cb;
+  int status;
 
-        if (user_data == NULL)
-                return (-EINVAL);
+  if (user_data == NULL)
+    return -EINVAL;
 
-        cb = user_data->data;
+  cb = user_data->data;
 
-        pthread_mutex_lock (&cb->send_lock);
+  pthread_mutex_lock(&cb->send_lock);
 
-        if (wh_callback_init (cb) != 0)
-        {
-                ERROR ("write_http plugin: wh_callback_init failed.");
-                pthread_mutex_unlock (&cb->send_lock);
-                return (-1);
-        }
+  if (wh_callback_init(cb) != 0) {
+    ERROR("write_http plugin: wh_callback_init failed.");
+    pthread_mutex_unlock(&cb->send_lock);
+    return -1;
+  }
 
-        status = wh_flush_nolock (timeout, cb);
-        pthread_mutex_unlock (&cb->send_lock);
+  status = wh_flush_nolock(timeout, cb);
+  pthread_mutex_unlock(&cb->send_lock);
 
-        return (status);
+  return status;
 } /* }}} int wh_flush */
 
-static void wh_callback_free (void *data) /* {{{ */
+static void wh_callback_free(void *data) /* {{{ */
 {
-        wh_callback_t *cb;
-
-        if (data == NULL)
-                return;
-
-        cb = data;
-
-        if (cb->send_buffer != NULL)
-                wh_flush_nolock (/* timeout = */ 0, cb);
-
-        if (cb->curl != NULL)
-        {
-                curl_easy_cleanup (cb->curl);
-                cb->curl = NULL;
-        }
-
-        if (cb->headers != NULL)
-        {
-                curl_slist_free_all (cb->headers);
-                cb->headers = NULL;
-        }
-
-        sfree (cb->name);
-        sfree (cb->location);
-        sfree (cb->user);
-        sfree (cb->pass);
-        sfree (cb->credentials);
-        sfree (cb->cacert);
-        sfree (cb->capath);
-        sfree (cb->clientkey);
-        sfree (cb->clientcert);
-        sfree (cb->clientkeypass);
-        sfree (cb->send_buffer);
-
-        sfree (cb);
+  wh_callback_t *cb;
+
+  if (data == NULL)
+    return;
+
+  cb = data;
+
+  if (cb->send_buffer != NULL)
+    wh_flush_nolock(/* timeout = */ 0, cb);
+
+  if (cb->curl != NULL) {
+    curl_easy_cleanup(cb->curl);
+    cb->curl = NULL;
+  }
+
+  if (cb->headers != NULL) {
+    curl_slist_free_all(cb->headers);
+    cb->headers = NULL;
+  }
+
+  sfree(cb->name);
+  sfree(cb->location);
+  sfree(cb->user);
+  sfree(cb->pass);
+  sfree(cb->credentials);
+  sfree(cb->cacert);
+  sfree(cb->capath);
+  sfree(cb->clientkey);
+  sfree(cb->clientcert);
+  sfree(cb->clientkeypass);
+  sfree(cb->send_buffer);
+  sfree(cb->metrics_prefix);
+
+  sfree(cb);
 } /* }}} void wh_callback_free */
 
-static int wh_write_command (const data_set_t *ds, const value_list_t *vl, /* {{{ */
-                wh_callback_t *cb)
-{
-        char key[10*DATA_MAX_NAME_LEN];
-        char values[512];
-        char command[1024];
-        size_t command_len;
-
-        int status;
-
-        if (0 != strcmp (ds->type, vl->type)) {
-                ERROR ("write_http plugin: DS type does not match "
-                                "value list type");
-                return -1;
-        }
-
-        /* Copy the identifier to `key' and escape it. */
-        status = FORMAT_VL (key, sizeof (key), vl);
-        if (status != 0) {
-                ERROR ("write_http plugin: error with format_name");
-                return (status);
-        }
-        escape_string (key, sizeof (key));
-
-        /* Convert the values to an ASCII representation and put that into
-         * `values'. */
-        status = format_values (values, sizeof (values), ds, vl, cb->store_rates);
-        if (status != 0) {
-                ERROR ("write_http plugin: error with "
-                                "wh_value_list_to_string");
-                return (status);
-        }
-
-        command_len = (size_t) ssnprintf (command, sizeof (command),
-                        "PUTVAL %s interval=%.3f %s\r\n",
-                        key,
-                        CDTIME_T_TO_DOUBLE (vl->interval),
-                        values);
-        if (command_len >= sizeof (command)) {
-                ERROR ("write_http plugin: Command buffer too small: "
-                                "Need %zu bytes.", command_len + 1);
-                return (-1);
-        }
-
-        pthread_mutex_lock (&cb->send_lock);
-        if (wh_callback_init (cb) != 0)
-        {
-                ERROR ("write_http plugin: wh_callback_init failed.");
-                pthread_mutex_unlock (&cb->send_lock);
-                return (-1);
-        }
-
-        if (command_len >= cb->send_buffer_free)
-        {
-                status = wh_flush_nolock (/* timeout = */ 0, cb);
-                if (status != 0)
-                {
-                        pthread_mutex_unlock (&cb->send_lock);
-                        return (status);
-                }
-        }
-        assert (command_len < cb->send_buffer_free);
-
-        /* `command_len + 1' because `command_len' does not include the
-         * trailing null byte. Neither does `send_buffer_fill'. */
-        memcpy (cb->send_buffer + cb->send_buffer_fill,
-                        command, command_len + 1);
-        cb->send_buffer_fill += command_len;
-        cb->send_buffer_free -= command_len;
-
-        DEBUG ("write_http plugin: <%s> buffer %zu/%zu (%g%%) \"%s\"",
-                        cb->location,
-                        cb->send_buffer_fill, cb->send_buffer_size,
-                        100.0 * ((double) cb->send_buffer_fill) / ((double) cb->send_buffer_size),
-                        command);
-
-        /* Check if we have enough space for this command. */
-        pthread_mutex_unlock (&cb->send_lock);
-
-        return (0);
+static int wh_write_command(const data_set_t *ds,
+                            const value_list_t *vl, /* {{{ */
+                            wh_callback_t *cb) {
+  char key[10 * DATA_MAX_NAME_LEN];
+  char values[512];
+  char command[1024];
+  size_t command_len;
+
+  int status;
+
+  /* sanity checks, primarily to make static analyzers happy. */
+  if ((cb == NULL) || (cb->send_buffer == NULL))
+    return -1;
+
+  if (strcmp(ds->type, vl->type) != 0) {
+    ERROR("write_http plugin: DS type does not match "
+          "value list type");
+    return -1;
+  }
+
+  /* Copy the identifier to `key' and escape it. */
+  status = FORMAT_VL(key, sizeof(key), vl);
+  if (status != 0) {
+    ERROR("write_http plugin: error with format_name");
+    return status;
+  }
+  escape_string(key, sizeof(key));
+
+  /* Convert the values to an ASCII representation and put that into
+   * `values'. */
+  status = format_values(values, sizeof(values), ds, vl, cb->store_rates);
+  if (status != 0) {
+    ERROR("write_http plugin: error with "
+          "wh_value_list_to_string");
+    return status;
+  }
+
+  command_len = (size_t)snprintf(command, sizeof(command),
+                                 "PUTVAL %s interval=%.3f %s\r\n", key,
+                                 CDTIME_T_TO_DOUBLE(vl->interval), values);
+  if (command_len >= sizeof(command)) {
+    ERROR("write_http plugin: Command buffer too small: "
+          "Need %zu bytes.",
+          command_len + 1);
+    return -1;
+  }
+
+  pthread_mutex_lock(&cb->send_lock);
+  if (wh_callback_init(cb) != 0) {
+    ERROR("write_http plugin: wh_callback_init failed.");
+    pthread_mutex_unlock(&cb->send_lock);
+    return -1;
+  }
+
+  if (command_len >= cb->send_buffer_free) {
+    status = wh_flush_nolock(/* timeout = */ 0, cb);
+    if (status != 0) {
+      pthread_mutex_unlock(&cb->send_lock);
+      return status;
+    }
+  }
+  assert(command_len < cb->send_buffer_free);
+
+  /* Make scan-build happy. */
+  assert(cb->send_buffer != NULL);
+
+  /* `command_len + 1' because `command_len' does not include the
+   * trailing null byte. Neither does `send_buffer_fill'. */
+  memcpy(cb->send_buffer + cb->send_buffer_fill, command, command_len + 1);
+  cb->send_buffer_fill += command_len;
+  cb->send_buffer_free -= command_len;
+
+  DEBUG("write_http plugin: <%s> buffer %zu/%zu (%g%%) \"%s\"", cb->location,
+        cb->send_buffer_fill, cb->send_buffer_size,
+        100.0 * ((double)cb->send_buffer_fill) / ((double)cb->send_buffer_size),
+        command);
+
+  /* Check if we have enough space for this command. */
+  pthread_mutex_unlock(&cb->send_lock);
+
+  return 0;
 } /* }}} int wh_write_command */
 
-static int wh_write_json (const data_set_t *ds, const value_list_t *vl, /* {{{ */
-                wh_callback_t *cb)
-{
-        int status;
-
-        pthread_mutex_lock (&cb->send_lock);
-        if (wh_callback_init (cb) != 0)
-        {
-                ERROR ("write_http plugin: wh_callback_init failed.");
-                pthread_mutex_unlock (&cb->send_lock);
-                return (-1);
-        }
-
-        status = format_json_value_list (cb->send_buffer,
-                        &cb->send_buffer_fill,
-                        &cb->send_buffer_free,
-                        ds, vl, cb->store_rates);
-        if (status == -ENOMEM)
-        {
-                status = wh_flush_nolock (/* timeout = */ 0, cb);
-                if (status != 0)
-                {
-                        wh_reset_buffer (cb);
-                        pthread_mutex_unlock (&cb->send_lock);
-                        return (status);
-                }
-
-                status = format_json_value_list (cb->send_buffer,
-                                &cb->send_buffer_fill,
-                                &cb->send_buffer_free,
-                                ds, vl, cb->store_rates);
-        }
-        if (status != 0)
-        {
-                pthread_mutex_unlock (&cb->send_lock);
-                return (status);
-        }
-
-        DEBUG ("write_http plugin: <%s> buffer %zu/%zu (%g%%)",
-                        cb->location,
-                        cb->send_buffer_fill, cb->send_buffer_size,
-                        100.0 * ((double) cb->send_buffer_fill) / ((double) cb->send_buffer_size));
-
-        /* Check if we have enough space for this command. */
-        pthread_mutex_unlock (&cb->send_lock);
-
-        return (0);
+static int wh_write_json(const data_set_t *ds, const value_list_t *vl, /* {{{ */
+                         wh_callback_t *cb) {
+  int status;
+
+  pthread_mutex_lock(&cb->send_lock);
+  if (wh_callback_init(cb) != 0) {
+    ERROR("write_http plugin: wh_callback_init failed.");
+    pthread_mutex_unlock(&cb->send_lock);
+    return -1;
+  }
+
+  status =
+      format_json_value_list(cb->send_buffer, &cb->send_buffer_fill,
+                             &cb->send_buffer_free, ds, vl, cb->store_rates);
+  if (status == -ENOMEM) {
+    status = wh_flush_nolock(/* timeout = */ 0, cb);
+    if (status != 0) {
+      wh_reset_buffer(cb);
+      pthread_mutex_unlock(&cb->send_lock);
+      return status;
+    }
+
+    status =
+        format_json_value_list(cb->send_buffer, &cb->send_buffer_fill,
+                               &cb->send_buffer_free, ds, vl, cb->store_rates);
+  }
+  if (status != 0) {
+    pthread_mutex_unlock(&cb->send_lock);
+    return status;
+  }
+
+  DEBUG("write_http plugin: <%s> buffer %zu/%zu (%g%%)", cb->location,
+        cb->send_buffer_fill, cb->send_buffer_size,
+        100.0 * ((double)cb->send_buffer_fill) /
+            ((double)cb->send_buffer_size));
+
+  /* Check if we have enough space for this command. */
+  pthread_mutex_unlock(&cb->send_lock);
+
+  return 0;
 } /* }}} int wh_write_json */
 
-static int wh_write_kairosdb (const data_set_t *ds, const value_list_t *vl, /* {{{ */
-                wh_callback_t *cb)
-{
-        int status;
-
-        pthread_mutex_lock (&cb->send_lock);
-
-        if (cb->curl == NULL)
-        {
-                status = wh_callback_init (cb);
-                if (status != 0)
-                {
-                        ERROR ("write_http plugin: wh_callback_init failed.");
-                        pthread_mutex_unlock (&cb->send_lock);
-                        return (-1);
-                }
-        }
-
-        status = format_kairosdb_value_list (cb->send_buffer,
-                        &cb->send_buffer_fill,
-                        &cb->send_buffer_free,
-                        ds, vl, cb->store_rates);
-        if (status == -ENOMEM)
-        {
-                status = wh_flush_nolock (/* timeout = */ 0, cb);
-                if (status != 0)
-                {
-                        wh_reset_buffer (cb);
-                        pthread_mutex_unlock (&cb->send_lock);
-                        return (status);
-                }
-
-                status = format_kairosdb_value_list (cb->send_buffer,
-                                &cb->send_buffer_fill,
-                                &cb->send_buffer_free,
-                                ds, vl, cb->store_rates);
-        }
-        if (status != 0)
-        {
-                pthread_mutex_unlock (&cb->send_lock);
-                return (status);
-        }
-
-        DEBUG ("write_http plugin: <%s> buffer %zu/%zu (%g%%)",
-                        cb->location,
-                        cb->send_buffer_fill, cb->send_buffer_size,
-                        100.0 * ((double) cb->send_buffer_fill) / ((double) cb->send_buffer_size));
-
-        /* Check if we have enough space for this command. */
-        pthread_mutex_unlock (&cb->send_lock);
-
-        return (0);
+static int wh_write_kairosdb(const data_set_t *ds,
+                             const value_list_t *vl, /* {{{ */
+                             wh_callback_t *cb) {
+  int status;
+
+  pthread_mutex_lock(&cb->send_lock);
+
+  if (cb->curl == NULL) {
+    status = wh_callback_init(cb);
+    if (status != 0) {
+      ERROR("write_http plugin: wh_callback_init failed.");
+      pthread_mutex_unlock(&cb->send_lock);
+      return -1;
+    }
+  }
+
+  status = format_kairosdb_value_list(
+      cb->send_buffer, &cb->send_buffer_fill, &cb->send_buffer_free, ds, vl,
+      cb->store_rates, (char const *const *)http_attrs, http_attrs_num,
+      cb->data_ttl, cb->metrics_prefix);
+  if (status == -ENOMEM) {
+    status = wh_flush_nolock(/* timeout = */ 0, cb);
+    if (status != 0) {
+      wh_reset_buffer(cb);
+      pthread_mutex_unlock(&cb->send_lock);
+      return status;
+    }
+
+    status = format_kairosdb_value_list(
+        cb->send_buffer, &cb->send_buffer_fill, &cb->send_buffer_free, ds, vl,
+        cb->store_rates, (char const *const *)http_attrs, http_attrs_num,
+        cb->data_ttl, cb->metrics_prefix);
+  }
+  if (status != 0) {
+    pthread_mutex_unlock(&cb->send_lock);
+    return status;
+  }
+
+  DEBUG("write_http plugin: <%s> buffer %zu/%zu (%g%%)", cb->location,
+        cb->send_buffer_fill, cb->send_buffer_size,
+        100.0 * ((double)cb->send_buffer_fill) /
+            ((double)cb->send_buffer_size));
+
+  /* Check if we have enough space for this command. */
+  pthread_mutex_unlock(&cb->send_lock);
+
+  return 0;
 } /* }}} int wh_write_kairosdb */
 
-static int wh_write (const data_set_t *ds, const value_list_t *vl, /* {{{ */
-                user_data_t *user_data)
-{
-        wh_callback_t *cb;
-        int status;
-
-        if (user_data == NULL)
-                return (-EINVAL);
-
-        cb = user_data->data;
-        assert (cb->send_metrics);
-
-        switch(cb->format) {
-            case WH_FORMAT_JSON:
-                status = wh_write_json (ds, vl, cb);
-                break;
-            case WH_FORMAT_KAIROSDB:
-                status = wh_write_kairosdb (ds, vl, cb);
-                break;
-            default:
-                status = wh_write_command (ds, vl, cb);
-                break;
-        }
-        return (status);
+static int wh_write(const data_set_t *ds, const value_list_t *vl, /* {{{ */
+                    user_data_t *user_data) {
+  wh_callback_t *cb;
+  int status;
+
+  if (user_data == NULL)
+    return -EINVAL;
+
+  cb = user_data->data;
+  assert(cb->send_metrics);
+
+  switch (cb->format) {
+  case WH_FORMAT_JSON:
+    status = wh_write_json(ds, vl, cb);
+    break;
+  case WH_FORMAT_KAIROSDB:
+    status = wh_write_kairosdb(ds, vl, cb);
+    break;
+  default:
+    status = wh_write_command(ds, vl, cb);
+    break;
+  }
+  return status;
 } /* }}} int wh_write */
 
-static int wh_notify (notification_t const *n, user_data_t *ud) /* {{{ */
+static int wh_notify(notification_t const *n, user_data_t *ud) /* {{{ */
 {
-        wh_callback_t *cb;
-        char alert[4096];
-        int status;
-
-        if ((ud == NULL) || (ud->data == NULL))
-                return (EINVAL);
-
-        cb = ud->data;
-        assert (cb->send_notifications);
-
-        status = format_json_notification (alert, sizeof (alert), n);
-        if (status != 0)
-        {
-                ERROR ("write_http plugin: formatting notification failed");
-                return status;
-        }
-
-        pthread_mutex_lock (&cb->send_lock);
-        if (wh_callback_init (cb) != 0)
-        {
-                ERROR ("write_http plugin: wh_callback_init failed.");
-                pthread_mutex_unlock (&cb->send_lock);
-                return (-1);
-        }
-
-        status = wh_post_nolock (cb, alert);
-        pthread_mutex_unlock (&cb->send_lock);
-
-        return (status);
+  wh_callback_t *cb;
+  char alert[4096];
+  int status;
+
+  if ((ud == NULL) || (ud->data == NULL))
+    return EINVAL;
+
+  cb = ud->data;
+  assert(cb->send_notifications);
+
+  status = format_json_notification(alert, sizeof(alert), n);
+  if (status != 0) {
+    ERROR("write_http plugin: formatting notification failed");
+    return status;
+  }
+
+  pthread_mutex_lock(&cb->send_lock);
+  if (wh_callback_init(cb) != 0) {
+    ERROR("write_http plugin: wh_callback_init failed.");
+    pthread_mutex_unlock(&cb->send_lock);
+    return -1;
+  }
+
+  status = wh_post_nolock(cb, alert);
+  pthread_mutex_unlock(&cb->send_lock);
+
+  return status;
 } /* }}} int wh_notify */
 
-static int config_set_format (wh_callback_t *cb, /* {{{ */
-                oconfig_item_t *ci)
-{
-        char *string;
-
-        if ((ci->values_num != 1)
-                        || (ci->values[0].type != OCONFIG_TYPE_STRING))
-        {
-                WARNING ("write_http plugin: The `%s' config option "
-                                "needs exactly one string argument.", ci->key);
-                return (-1);
-        }
-
-        string = ci->values[0].value.string;
-        if (strcasecmp ("Command", string) == 0)
-                cb->format = WH_FORMAT_COMMAND;
-        else if (strcasecmp ("JSON", string) == 0)
-                cb->format = WH_FORMAT_JSON;
-        else if (strcasecmp ("KAIROSDB", string) == 0)
-                cb->format = WH_FORMAT_KAIROSDB;
-        else
-        {
-                ERROR ("write_http plugin: Invalid format string: %s",
-                                string);
-                return (-1);
-        }
-
-        return (0);
+static int config_set_format(wh_callback_t *cb, /* {{{ */
+                             oconfig_item_t *ci) {
+  char *string;
+
+  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING)) {
+    WARNING("write_http plugin: The `%s' config option "
+            "needs exactly one string argument.",
+            ci->key);
+    return -1;
+  }
+
+  string = ci->values[0].value.string;
+  if (strcasecmp("Command", string) == 0)
+    cb->format = WH_FORMAT_COMMAND;
+  else if (strcasecmp("JSON", string) == 0)
+    cb->format = WH_FORMAT_JSON;
+  else if (strcasecmp("KAIROSDB", string) == 0)
+    cb->format = WH_FORMAT_KAIROSDB;
+  else {
+    ERROR("write_http plugin: Invalid format string: %s", string);
+    return -1;
+  }
+
+  return 0;
 } /* }}} int config_set_format */
 
-static int wh_config_append_string (const char *name, struct curl_slist **dest, /* {{{ */
-    oconfig_item_t *ci)
-{
+static int wh_config_append_string(const char *name,
+                                   struct curl_slist **dest, /* {{{ */
+                                   oconfig_item_t *ci) {
   struct curl_slist *temp = NULL;
-  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING))
-  {
-    WARNING ("write_http plugin: `%s' needs exactly one string argument.", name);
-    return (-1);
+  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING)) {
+    WARNING("write_http plugin: `%s' needs exactly one string argument.", name);
+    return -1;
   }
 
   temp = curl_slist_append(*dest, ci->values[0].value.string);
   if (temp == NULL)
-    return (-1);
+    return -1;
 
   *dest = temp;
 
-  return (0);
+  return 0;
 } /* }}} int wh_config_append_string */
 
-static int wh_config_node (oconfig_item_t *ci) /* {{{ */
+static int wh_config_node(oconfig_item_t *ci) /* {{{ */
 {
-        wh_callback_t *cb;
-        int buffer_size = 0;
-        user_data_t user_data = { 0 };
-        char callback_name[DATA_MAX_NAME_LEN];
-        int status = 0;
-
-        cb = calloc (1, sizeof (*cb));
-        if (cb == NULL)
-        {
-                ERROR ("write_http plugin: calloc failed.");
-                return (-1);
-        }
-        cb->verify_peer = 1;
-        cb->verify_host = 1;
-        cb->format = WH_FORMAT_COMMAND;
+  wh_callback_t *cb;
+  int buffer_size = 0;
+  char callback_name[DATA_MAX_NAME_LEN];
+  int status = 0;
+
+  cb = calloc(1, sizeof(*cb));
+  if (cb == NULL) {
+    ERROR("write_http plugin: calloc failed.");
+    return -1;
+  }
+  cb->verify_peer = 1;
+  cb->verify_host = 1;
+  cb->format = WH_FORMAT_COMMAND;
+  cb->sslversion = CURL_SSLVERSION_DEFAULT;
+  cb->low_speed_limit = 0;
+  cb->timeout = 0;
+  cb->log_http_error = 0;
+  cb->headers = NULL;
+  cb->send_metrics = 1;
+  cb->send_notifications = 0;
+  cb->data_ttl = 0;
+  cb->metrics_prefix = strdup(WRITE_HTTP_DEFAULT_PREFIX);
+
+  if (cb->metrics_prefix == NULL) {
+    ERROR("write_http plugin: strdup failed.");
+    sfree(cb);
+    return -1;
+  }
+
+  pthread_mutex_init(&cb->send_lock, /* attr = */ NULL);
+
+  cf_util_get_string(ci, &cb->name);
+
+  /* FIXME: Remove this legacy mode in version 6. */
+  if (strcasecmp("URL", ci->key) == 0)
+    cf_util_get_string(ci, &cb->location);
+
+  for (int i = 0; i < ci->children_num; i++) {
+    oconfig_item_t *child = ci->children + i;
+
+    if (strcasecmp("URL", child->key) == 0)
+      status = cf_util_get_string(child, &cb->location);
+    else if (strcasecmp("User", child->key) == 0)
+      status = cf_util_get_string(child, &cb->user);
+    else if (strcasecmp("Password", child->key) == 0)
+      status = cf_util_get_string(child, &cb->pass);
+    else if (strcasecmp("VerifyPeer", child->key) == 0)
+      status = cf_util_get_boolean(child, &cb->verify_peer);
+    else if (strcasecmp("VerifyHost", child->key) == 0)
+      status = cf_util_get_boolean(child, &cb->verify_host);
+    else if (strcasecmp("CACert", child->key) == 0)
+      status = cf_util_get_string(child, &cb->cacert);
+    else if (strcasecmp("CAPath", child->key) == 0)
+      status = cf_util_get_string(child, &cb->capath);
+    else if (strcasecmp("ClientKey", child->key) == 0)
+      status = cf_util_get_string(child, &cb->clientkey);
+    else if (strcasecmp("ClientCert", child->key) == 0)
+      status = cf_util_get_string(child, &cb->clientcert);
+    else if (strcasecmp("ClientKeyPass", child->key) == 0)
+      status = cf_util_get_string(child, &cb->clientkeypass);
+    else if (strcasecmp("SSLVersion", child->key) == 0) {
+      char *value = NULL;
+
+      status = cf_util_get_string(child, &value);
+      if (status != 0)
+        break;
+
+      if (value == NULL || strcasecmp("default", value) == 0)
         cb->sslversion = CURL_SSLVERSION_DEFAULT;
-        cb->low_speed_limit = 0;
-        cb->timeout = 0;
-        cb->log_http_error = 0;
-        cb->headers = NULL;
-        cb->send_metrics = 1;
-        cb->send_notifications = 0;
-
-        pthread_mutex_init (&cb->send_lock, /* attr = */ NULL);
-
-        cf_util_get_string (ci, &cb->name);
-
-        /* FIXME: Remove this legacy mode in version 6. */
-        if (strcasecmp ("URL", ci->key) == 0)
-                cf_util_get_string (ci, &cb->location);
-
-        for (int i = 0; i < ci->children_num; i++)
-        {
-                oconfig_item_t *child = ci->children + i;
-
-                if (strcasecmp ("URL", child->key) == 0)
-                        status = cf_util_get_string (child, &cb->location);
-                else if (strcasecmp ("User", child->key) == 0)
-                        status = cf_util_get_string (child, &cb->user);
-                else if (strcasecmp ("Password", child->key) == 0)
-                        status = cf_util_get_string (child, &cb->pass);
-                else if (strcasecmp ("VerifyPeer", child->key) == 0)
-                        status = cf_util_get_boolean (child, &cb->verify_peer);
-                else if (strcasecmp ("VerifyHost", child->key) == 0)
-                        status = cf_util_get_boolean (child, &cb->verify_host);
-                else if (strcasecmp ("CACert", child->key) == 0)
-                        status = cf_util_get_string (child, &cb->cacert);
-                else if (strcasecmp ("CAPath", child->key) == 0)
-                        status = cf_util_get_string (child, &cb->capath);
-                else if (strcasecmp ("ClientKey", child->key) == 0)
-                        status = cf_util_get_string (child, &cb->clientkey);
-                else if (strcasecmp ("ClientCert", child->key) == 0)
-                        status = cf_util_get_string (child, &cb->clientcert);
-                else if (strcasecmp ("ClientKeyPass", child->key) == 0)
-                        status = cf_util_get_string (child, &cb->clientkeypass);
-                else if (strcasecmp ("SSLVersion", child->key) == 0)
-                {
-                        char *value = NULL;
-
-                        status = cf_util_get_string (child, &value);
-                        if (status != 0)
-                                break;
-
-                        if (value == NULL || strcasecmp ("default", value) == 0)
-                                cb->sslversion = CURL_SSLVERSION_DEFAULT;
-                        else if (strcasecmp ("SSLv2", value) == 0)
-                                cb->sslversion = CURL_SSLVERSION_SSLv2;
-                        else if (strcasecmp ("SSLv3", value) == 0)
-                                cb->sslversion = CURL_SSLVERSION_SSLv3;
-                        else if (strcasecmp ("TLSv1", value) == 0)
-                                cb->sslversion = CURL_SSLVERSION_TLSv1;
-#if (LIBCURL_VERSION_MAJOR > 7) || (LIBCURL_VERSION_MAJOR == 7 && LIBCURL_VERSION_MINOR >= 34)
-                        else if (strcasecmp ("TLSv1_0", value) == 0)
-                                cb->sslversion = CURL_SSLVERSION_TLSv1_0;
-                        else if (strcasecmp ("TLSv1_1", value) == 0)
-                                cb->sslversion = CURL_SSLVERSION_TLSv1_1;
-                        else if (strcasecmp ("TLSv1_2", value) == 0)
-                                cb->sslversion = CURL_SSLVERSION_TLSv1_2;
+      else if (strcasecmp("SSLv2", value) == 0)
+        cb->sslversion = CURL_SSLVERSION_SSLv2;
+      else if (strcasecmp("SSLv3", value) == 0)
+        cb->sslversion = CURL_SSLVERSION_SSLv3;
+      else if (strcasecmp("TLSv1", value) == 0)
+        cb->sslversion = CURL_SSLVERSION_TLSv1;
+#if (LIBCURL_VERSION_MAJOR > 7) ||                                             \
+    (LIBCURL_VERSION_MAJOR == 7 && LIBCURL_VERSION_MINOR >= 34)
+      else if (strcasecmp("TLSv1_0", value) == 0)
+        cb->sslversion = CURL_SSLVERSION_TLSv1_0;
+      else if (strcasecmp("TLSv1_1", value) == 0)
+        cb->sslversion = CURL_SSLVERSION_TLSv1_1;
+      else if (strcasecmp("TLSv1_2", value) == 0)
+        cb->sslversion = CURL_SSLVERSION_TLSv1_2;
 #endif
-                        else
-                        {
-                                ERROR ("write_http plugin: Invalid SSLVersion "
-                                                "option: %s.", value);
-                                status = EINVAL;
-                        }
-
-                        sfree(value);
-                }
-                else if (strcasecmp ("Format", child->key) == 0)
-                        status = config_set_format (cb, child);
-                else if (strcasecmp ("Metrics", child->key) == 0)
-                        cf_util_get_boolean (child, &cb->send_metrics);
-                else if (strcasecmp ("Notifications", child->key) == 0)
-                        cf_util_get_boolean (child, &cb->send_notifications);
-                else if (strcasecmp ("StoreRates", child->key) == 0)
-                        status = cf_util_get_boolean (child, &cb->store_rates);
-                else if (strcasecmp ("BufferSize", child->key) == 0)
-                        status = cf_util_get_int (child, &buffer_size);
-                else if (strcasecmp ("LowSpeedLimit", child->key) == 0)
-                        status = cf_util_get_int (child, &cb->low_speed_limit);
-                else if (strcasecmp ("Timeout", child->key) == 0)
-                        status = cf_util_get_int (child, &cb->timeout);
-                else if (strcasecmp ("LogHttpError", child->key) == 0)
-                        status = cf_util_get_boolean (child, &cb->log_http_error);
-                else if (strcasecmp ("Header", child->key) == 0)
-                        status = wh_config_append_string ("Header", &cb->headers, child);
-                else
-                {
-                        ERROR ("write_http plugin: Invalid configuration "
-                                        "option: %s.", child->key);
-                        status = EINVAL;
-                }
-
-                if (status != 0)
-                        break;
-        }
-
-        if (status != 0)
-        {
-                wh_callback_free (cb);
-                return (status);
-        }
-
-        if (cb->location == NULL)
-        {
-                ERROR ("write_http plugin: no URL defined for instance '%s'",
-                        cb->name);
-                wh_callback_free (cb);
-                return (-1);
-        }
-
-        if (!cb->send_metrics && !cb->send_notifications)
-        {
-                ERROR ("write_http plugin: Neither metrics nor notifications "
-                       "are enabled for \"%s\".", cb->name);
-                wh_callback_free (cb);
-                return (-1);
-        }
-
-        if (cb->low_speed_limit > 0)
-                cb->low_speed_time = CDTIME_T_TO_TIME_T(plugin_get_interval());
-
-        /* Determine send_buffer_size. */
-        cb->send_buffer_size = WRITE_HTTP_DEFAULT_BUFFER_SIZE;
-        if (buffer_size >= 1024)
-                cb->send_buffer_size = (size_t) buffer_size;
-        else if (buffer_size != 0)
-                ERROR ("write_http plugin: Ignoring invalid BufferSize setting (%d).",
-                                buffer_size);
-
-        /* Allocate the buffer. */
-        cb->send_buffer = malloc (cb->send_buffer_size);
-        if (cb->send_buffer == NULL)
-        {
-                ERROR ("write_http plugin: malloc(%zu) failed.", cb->send_buffer_size);
-                wh_callback_free (cb);
-                return (-1);
-        }
-        /* Nulls the buffer and sets ..._free and ..._fill. */
-        wh_reset_buffer (cb);
-
-        ssnprintf (callback_name, sizeof (callback_name), "write_http/%s",
-                        cb->name);
-        DEBUG ("write_http: Registering write callback '%s' with URL '%s'",
-                        callback_name, cb->location);
-
-        user_data.data = cb;
-        plugin_register_flush (callback_name, wh_flush, &user_data);
-
-        user_data.free_func = wh_callback_free;
-
-        if (cb->send_metrics)
-        {
-                plugin_register_write (callback_name, wh_write, &user_data);
-                user_data.free_func = NULL;
-
-                plugin_register_flush (callback_name, wh_flush, &user_data);
-        }
-
-        if (cb->send_notifications)
-        {
-                plugin_register_notification (callback_name, wh_notify, &user_data);
-                user_data.free_func = NULL;
-        }
-
-        return (0);
+      else {
+        ERROR("write_http plugin: Invalid SSLVersion "
+              "option: %s.",
+              value);
+        status = EINVAL;
+      }
+
+      sfree(value);
+    } else if (strcasecmp("Format", child->key) == 0)
+      status = config_set_format(cb, child);
+    else if (strcasecmp("Metrics", child->key) == 0)
+      cf_util_get_boolean(child, &cb->send_metrics);
+    else if (strcasecmp("Notifications", child->key) == 0)
+      cf_util_get_boolean(child, &cb->send_notifications);
+    else if (strcasecmp("StoreRates", child->key) == 0)
+      status = cf_util_get_boolean(child, &cb->store_rates);
+    else if (strcasecmp("BufferSize", child->key) == 0)
+      status = cf_util_get_int(child, &buffer_size);
+    else if (strcasecmp("LowSpeedLimit", child->key) == 0)
+      status = cf_util_get_int(child, &cb->low_speed_limit);
+    else if (strcasecmp("Timeout", child->key) == 0)
+      status = cf_util_get_int(child, &cb->timeout);
+    else if (strcasecmp("LogHttpError", child->key) == 0)
+      status = cf_util_get_boolean(child, &cb->log_http_error);
+    else if (strcasecmp("Header", child->key) == 0)
+      status = wh_config_append_string("Header", &cb->headers, child);
+    else if (strcasecmp("Attribute", child->key) == 0) {
+      char *key = NULL;
+      char *val = NULL;
+
+      if (child->values_num != 2) {
+        WARNING("write_http plugin: Attribute need both a key and a value.");
+        break;
+      }
+      if (child->values[0].type != OCONFIG_TYPE_STRING ||
+          child->values[1].type != OCONFIG_TYPE_STRING) {
+        WARNING("write_http plugin: Attribute needs string arguments.");
+        break;
+      }
+      if ((key = strdup(child->values[0].value.string)) == NULL) {
+        WARNING("cannot allocate memory for attribute key.");
+        break;
+      }
+      if ((val = strdup(child->values[1].value.string)) == NULL) {
+        WARNING("cannot allocate memory for attribute value.");
+        sfree(key);
+        break;
+      }
+      strarray_add(&http_attrs, &http_attrs_num, key);
+      strarray_add(&http_attrs, &http_attrs_num, val);
+      DEBUG("write_http plugin: got attribute: %s => %s", key, val);
+      sfree(key);
+      sfree(val);
+    } else if (strcasecmp("TTL", child->key) == 0) {
+      status = cf_util_get_int(child, &cb->data_ttl);
+    } else if (strcasecmp("Prefix", child->key) == 0) {
+      status = cf_util_get_string(child, &cb->metrics_prefix);
+    } else {
+      ERROR("write_http plugin: Invalid configuration "
+            "option: %s.",
+            child->key);
+      status = EINVAL;
+    }
+
+    if (status != 0)
+      break;
+  }
+
+  if (status != 0) {
+    wh_callback_free(cb);
+    return status;
+  }
+
+  if (cb->location == NULL) {
+    ERROR("write_http plugin: no URL defined for instance '%s'", cb->name);
+    wh_callback_free(cb);
+    return -1;
+  }
+
+  if (!cb->send_metrics && !cb->send_notifications) {
+    ERROR("write_http plugin: Neither metrics nor notifications "
+          "are enabled for \"%s\".",
+          cb->name);
+    wh_callback_free(cb);
+    return -1;
+  }
+
+  if (strlen(cb->metrics_prefix) == 0)
+    sfree(cb->metrics_prefix);
+
+  if (cb->low_speed_limit > 0)
+    cb->low_speed_time = CDTIME_T_TO_TIME_T(plugin_get_interval());
+
+  /* Determine send_buffer_size. */
+  cb->send_buffer_size = WRITE_HTTP_DEFAULT_BUFFER_SIZE;
+  if (buffer_size >= 1024)
+    cb->send_buffer_size = (size_t)buffer_size;
+  else if (buffer_size != 0)
+    ERROR("write_http plugin: Ignoring invalid BufferSize setting (%d).",
+          buffer_size);
+
+  /* Allocate the buffer. */
+  cb->send_buffer = malloc(cb->send_buffer_size);
+  if (cb->send_buffer == NULL) {
+    ERROR("write_http plugin: malloc(%zu) failed.", cb->send_buffer_size);
+    wh_callback_free(cb);
+    return -1;
+  }
+  /* Nulls the buffer and sets ..._free and ..._fill. */
+  wh_reset_buffer(cb);
+
+  snprintf(callback_name, sizeof(callback_name), "write_http/%s", cb->name);
+  DEBUG("write_http: Registering write callback '%s' with URL '%s'",
+        callback_name, cb->location);
+
+  user_data_t user_data = {
+      .data = cb, .free_func = wh_callback_free,
+  };
+
+  if (cb->send_metrics) {
+    plugin_register_write(callback_name, wh_write, &user_data);
+    user_data.free_func = NULL;
+
+    plugin_register_flush(callback_name, wh_flush, &user_data);
+  }
+
+  if (cb->send_notifications) {
+    plugin_register_notification(callback_name, wh_notify, &user_data);
+    user_data.free_func = NULL;
+  }
+
+  return 0;
 } /* }}} int wh_config_node */
 
-static int wh_config (oconfig_item_t *ci) /* {{{ */
+static int wh_config(oconfig_item_t *ci) /* {{{ */
 {
-        for (int i = 0; i < ci->children_num; i++)
-        {
-                oconfig_item_t *child = ci->children + i;
-
-                if (strcasecmp ("Node", child->key) == 0)
-                        wh_config_node (child);
-                /* FIXME: Remove this legacy mode in version 6. */
-                else if (strcasecmp ("URL", child->key) == 0) {
-                        WARNING ("write_http plugin: Legacy <URL> block found. "
-                                "Please use <Node> instead.");
-                        wh_config_node (child);
-                }
-                else
-                {
-                        ERROR ("write_http plugin: Invalid configuration "
-                                        "option: %s.", child->key);
-                }
-        }
-
-        return (0);
+  for (int i = 0; i < ci->children_num; i++) {
+    oconfig_item_t *child = ci->children + i;
+
+    if (strcasecmp("Node", child->key) == 0)
+      wh_config_node(child);
+    /* FIXME: Remove this legacy mode in version 6. */
+    else if (strcasecmp("URL", child->key) == 0) {
+      WARNING("write_http plugin: Legacy <URL> block found. "
+              "Please use <Node> instead.");
+      wh_config_node(child);
+    } else {
+      ERROR("write_http plugin: Invalid configuration "
+            "option: %s.",
+            child->key);
+    }
+  }
+
+  return 0;
 } /* }}} int wh_config */
 
-static int wh_init (void) /* {{{ */
+static int wh_init(void) /* {{{ */
 {
-        /* Call this while collectd is still single-threaded to avoid
-         * initialization issues in libgcrypt. */
-        curl_global_init (CURL_GLOBAL_SSL);
-        return (0);
+  /* Call this while collectd is still single-threaded to avoid
+   * initialization issues in libgcrypt. */
+  curl_global_init(CURL_GLOBAL_SSL);
+  return 0;
 } /* }}} int wh_init */
 
-void module_register (void) /* {{{ */
+void module_register(void) /* {{{ */
 {
-        plugin_register_complex_config ("write_http", wh_config);
-        plugin_register_init ("write_http", wh_init);
+  plugin_register_complex_config("write_http", wh_config);
+  plugin_register_init("write_http", wh_init);
 } /* }}} void module_register */
-
-/* vim: set fdm=marker sw=8 ts=8 tw=78 et : */