write_http plugin: Make it possible to send values as JSON.

diff --git a/src/Makefile.am b/src/Makefile.am
index 0dd5ff31e6968655dce9766d68a32fb2c7087fdb..25711d6c984e881cb772b4298d662c5acf8593bf 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1044,7 +1044,8 @@ endif
 
 if BUILD_PLUGIN_WRITE_HTTP
 pkglib_LTLIBRARIES += write_http.la
-write_http_la_SOURCES = write_http.c
+write_http_la_SOURCES = write_http.c \
+                       utils_format_json.c utils_format_json.h
 write_http_la_LDFLAGS = -module -avoid-version
 write_http_la_CFLAGS = $(AM_CFLAGS)
 write_http_la_LIBADD =

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 9419fb99a880b82fb15939fc5a1dbff7f72e503c..69f7308befe716923dd780c9216f6738375ddbcd 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -3502,6 +3502,14 @@ File that holds one or more SSL certificates. If you want to use HTTPS you will
 possibly need this option. What CA certificates come bundled with C<libcurl>
 and are checked by default depends on the distribution you use.
 
+=item B<Format> B<Command>|B<JSON>
+
+Format of the output to generate. If set to B<Command>, will create output that
+is understood by the I<Exec> and I<UnixSock> plugins. When set to B<JSON>, will
+create output in the I<JavaScript Object Notation> (JSON).
+
+Defaults to B<Command>.
+
 =back
 
 =head1 THRESHOLD CONFIGURATION

diff --git a/src/utils_format_json.c b/src/utils_format_json.c
new file mode 100644 (file)
index 0000000..a919316
--- /dev/null
+++ b/src/utils_format_json.c
@@ -0,0 +1,268 @@
+/**
+ * collectd - src/utils_format_json.c
+ * Copyright (C) 2009  Florian octo Forster
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *   Florian octo Forster <octo at verplant.org>
+ **/
+
+#include "collectd.h"
+#include "plugin.h"
+#include "common.h"
+
+#include "utils_format_json.h"
+
+static int escape_string (char *buffer, size_t buffer_size, /* {{{ */
+    const char *string)
+{
+  size_t src_pos;
+  size_t dst_pos;
+
+  if ((buffer == NULL) || (string == NULL))
+    return (-EINVAL);
+
+  if (buffer_size < 3)
+    return (-ENOMEM);
+
+  dst_pos = 0;
+
+#define BUFFER_ADD(c) do { \
+  if (dst_pos >= (buffer_size - 1)) { \
+    buffer[buffer_size - 1] = 0; \
+    return (-ENOMEM); \
+  } \
+  buffer[dst_pos] = (c); \
+  dst_pos++; \
+} while (0)
+
+  /* Escape special characters */
+  BUFFER_ADD ('"');
+  for (src_pos = 0; string[src_pos] != 0; src_pos++)
+  {
+    if ((string[src_pos] == '"')
+        || (string[src_pos] == '\\'))
+    {
+      BUFFER_ADD ('\\');
+      BUFFER_ADD (string[src_pos]);
+    }
+    else if (string[src_pos] <= 0x001F)
+      BUFFER_ADD ('?');
+    else
+      BUFFER_ADD (string[src_pos]);
+  } /* for */
+  BUFFER_ADD ('"');
+  buffer[dst_pos] = 0;
+
+#undef BUFFER_ADD
+
+  return (0);
+} /* }}} int buffer_add_string */
+
+static int values_to_json (char *buffer, size_t buffer_size, /* {{{ */
+                const data_set_t *ds, const value_list_t *vl)
+{
+  size_t offset = 0;
+  int i;
+
+  memset (buffer, 0, buffer_size);
+
+#define BUFFER_ADD(...) do { \
+  int status; \
+  status = ssnprintf (buffer + offset, buffer_size - offset, \
+      __VA_ARGS__); \
+  if (status < 1) \
+    return (-1); \
+  else if (((size_t) status) >= (buffer_size - offset)) \
+    return (-ENOMEM); \
+  else \
+  offset += ((size_t) status); \
+} while (0)
+
+  BUFFER_ADD ("[");
+  for (i = 0; i < ds->ds_num; i++)
+  {
+    if (i > 0)
+      BUFFER_ADD (",");
+
+    if (ds->ds[i].type == DS_TYPE_GAUGE)
+      BUFFER_ADD ("%g", vl->values[i].gauge);
+    else if (ds->ds[i].type == DS_TYPE_COUNTER)
+      BUFFER_ADD ("%llu", vl->values[i].counter);
+    else if (ds->ds[i].type == DS_TYPE_DERIVE)
+      BUFFER_ADD ("%"PRIi64, vl->values[i].derive);
+    else if (ds->ds[i].type == DS_TYPE_ABSOLUTE)
+      BUFFER_ADD ("%"PRIu64, vl->values[i].absolute);
+    else
+    {
+      ERROR ("format_json: Unknown data source type: %i",
+          ds->ds[i].type);
+      return (-1);
+    }
+  } /* for ds->ds_num */
+  BUFFER_ADD ("]");
+
+#undef BUFFER_ADD
+
+  DEBUG ("format_json: values_to_json: buffer = %s;", buffer);
+
+  return (0);
+} /* }}} int values_to_json */
+
+static int value_list_to_json (char *buffer, size_t buffer_size, /* {{{ */
+                const data_set_t *ds, const value_list_t *vl)
+{
+  char temp[512];
+  size_t offset = 0;
+  int status;
+
+  memset (buffer, 0, buffer_size);
+
+#define BUFFER_ADD(...) do { \
+  status = ssnprintf (buffer + offset, buffer_size - offset, \
+      __VA_ARGS__); \
+  if (status < 1) \
+    return (-1); \
+  else if (((size_t) status) >= (buffer_size - offset)) \
+    return (-ENOMEM); \
+  else \
+    offset += ((size_t) status); \
+} while (0)
+
+  /* All value lists have a leading comma. The first one will be replaced with
+   * a square bracket in `format_json_finalize'. */
+  BUFFER_ADD (",{");
+
+  status = values_to_json (temp, sizeof (temp), ds, vl);
+  if (status != 0)
+    return (status);
+  BUFFER_ADD ("\"values\":%s", temp);
+
+  BUFFER_ADD (",\"time\":%lu", (unsigned long) vl->time);
+  BUFFER_ADD (",\"interval\":%i", vl->interval);
+
+#define BUFFER_ADD_KEYVAL(key, value) do { \
+  status = escape_string (temp, sizeof (temp), (value)); \
+  if (status != 0) \
+    return (status); \
+  BUFFER_ADD (",\"%s\":%s", (key), temp); \
+} while (0)
+
+  BUFFER_ADD_KEYVAL ("host", vl->host);
+  BUFFER_ADD_KEYVAL ("plugin", vl->plugin);
+  BUFFER_ADD_KEYVAL ("plugin_instance", vl->plugin_instance);
+  BUFFER_ADD_KEYVAL ("type", vl->type);
+  BUFFER_ADD_KEYVAL ("type_instance", vl->type_instance);
+
+  BUFFER_ADD ("}");
+
+#undef BUFFER_ADD_KEYVAL
+#undef BUFFER_ADD
+
+  DEBUG ("format_json: value_list_to_json: buffer = %s;", buffer);
+
+  return (0);
+} /* }}} int value_list_to_json */
+
+static int format_json_value_list_nocheck (char *buffer, /* {{{ */
+    size_t *ret_buffer_fill, size_t *ret_buffer_free,
+    const data_set_t *ds, const value_list_t *vl,
+    size_t temp_size)
+{
+  char temp[temp_size];
+  int status;
+
+  status = value_list_to_json (temp, sizeof (temp), ds, vl);
+  if (status != 0)
+    return (status);
+  temp_size = strlen (temp);
+
+  memcpy (buffer + (*ret_buffer_fill), temp, temp_size + 1);
+  (*ret_buffer_fill) += temp_size;
+  (*ret_buffer_free) -= temp_size;
+
+  return (0);
+} /* }}} int format_json_value_list_nocheck */
+
+int format_json_initialize (char *buffer, /* {{{ */
+    size_t *ret_buffer_fill, size_t *ret_buffer_free)
+{
+  size_t buffer_fill;
+  size_t buffer_free;
+
+  if ((buffer == NULL) || (ret_buffer_fill == NULL) || (ret_buffer_free == NULL))
+    return (-EINVAL);
+
+  buffer_fill = *ret_buffer_fill;
+  buffer_free = *ret_buffer_free;
+
+  buffer_free = buffer_fill + buffer_free;
+  buffer_fill = 0;
+
+  if (buffer_free < 3)
+    return (-ENOMEM);
+
+  memset (buffer, 0, buffer_free);
+  *ret_buffer_fill = buffer_fill;
+  *ret_buffer_free = buffer_free;
+
+  return (0);
+} /* }}} int format_json_initialize */
+
+int format_json_finalize (char *buffer, /* {{{ */
+    size_t *ret_buffer_fill, size_t *ret_buffer_free)
+{
+  size_t pos;
+
+  if ((buffer == NULL) || (ret_buffer_fill == NULL) || (ret_buffer_free == NULL))
+    return (-EINVAL);
+
+  if (*ret_buffer_free < 2)
+    return (-ENOMEM);
+
+  /* Replace the leading comma added in `value_list_to_json' with a square
+   * bracket. */
+  if (buffer[0] != ',')
+    return (-EINVAL);
+  buffer[0] = '[';
+
+  pos = *ret_buffer_fill;
+  buffer[pos] = ']';
+  buffer[pos+1] = 0;
+
+  (*ret_buffer_fill)++;
+  (*ret_buffer_free)--;
+
+  return (0);
+} /* }}} int format_json_finalize */
+
+int format_json_value_list (char *buffer, /* {{{ */
+    size_t *ret_buffer_fill, size_t *ret_buffer_free,
+    const data_set_t *ds, const value_list_t *vl)
+{
+  if ((buffer == NULL)
+      || (ret_buffer_fill == NULL) || (ret_buffer_free == NULL)
+      || (ds == NULL) || (vl == NULL))
+    return (-EINVAL);
+
+  if (*ret_buffer_free < 3)
+    return (-ENOMEM);
+
+  return (format_json_value_list_nocheck (buffer,
+        ret_buffer_fill, ret_buffer_free, ds, vl,
+        (*ret_buffer_free) - 2));
+} /* }}} int format_json_value_list */
+
+/* vim: set sw=2 sts=2 et fdm=marker : */

diff --git a/src/utils_format_json.h b/src/utils_format_json.h
new file mode 100644 (file)
index 0000000..880a79d
--- /dev/null
+++ b/src/utils_format_json.h
@@ -0,0 +1,36 @@
+/**
+ * collectd - src/utils_format_json.c
+ * Copyright (C) 2009  Florian octo Forster
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *   Florian octo Forster <octo at verplant.org>
+ **/
+
+#ifndef UTILS_FORMAT_JSON_H
+#define UTILS_FORMAT_JSON_H 1
+
+#include "collectd.h"
+#include "plugin.h"
+
+int format_json_initialize (char *buffer,
+    size_t *ret_buffer_fill, size_t *ret_buffer_free);
+int format_json_value_list (char *buffer,
+    size_t *ret_buffer_fill, size_t *ret_buffer_free,
+    const data_set_t *ds, const value_list_t *vl);
+int format_json_finalize (char *buffer,
+    size_t *ret_buffer_fill, size_t *ret_buffer_free);
+
+#endif /* UTILS_FORMAT_JSON_H */

diff --git a/src/write_http.c b/src/write_http.c
index 30693e02905dec643f422024bc8d5f523fdb8222..f14636bde5ec79e355aa2166e152992f8b651cfd 100644 (file)
--- a/src/write_http.c
+++ b/src/write_http.c
@@ -28,6 +28,7 @@
 #include "common.h"
 #include "utils_cache.h"
 #include "utils_parse_option.h"
+#include "utils_format_json.h"
 
 #if HAVE_PTHREAD_H
 # include <pthread.h>
@@ -49,6 +50,10 @@ struct wh_callback_s
         int   verify_host;
         char *cacert;
 
+#define WH_FORMAT_COMMAND 0
+#define WH_FORMAT_JSON    1
+        int format;
+
         CURL *curl;
         char curl_errbuf[CURL_ERROR_SIZE];
 
@@ -67,6 +72,13 @@ static void wh_reset_buffer (wh_callback_t *cb)  /* {{{ */
         cb->send_buffer_free = sizeof (cb->send_buffer);
         cb->send_buffer_fill = 0;
         cb->send_buffer_init_time = time (NULL);
+
+        if (cb->format == WH_FORMAT_JSON)
+        {
+                format_json_initialize (cb->send_buffer,
+                                &cb->send_buffer_fill,
+                                &cb->send_buffer_free);
+        }
 } /* }}} wh_reset_buffer */
 
 static int wh_send_buffer (wh_callback_t *cb) /* {{{ */
@@ -102,7 +114,10 @@ static int wh_callback_init (wh_callback_t *cb) /* {{{ */
 
         headers = NULL;
         headers = curl_slist_append (headers, "Accept:  */*");
-        headers = curl_slist_append (headers, "Content-Type: text/plain");
+        if (cb->format == WH_FORMAT_JSON)
+                headers = curl_slist_append (headers, "Content-Type: application/json");
+        else
+                headers = curl_slist_append (headers, "Content-Type: text/plain");
         headers = curl_slist_append (headers, "Expect:");
         curl_easy_setopt (cb->curl, CURLOPT_HTTPHEADER, headers);
 
@@ -158,14 +173,46 @@ static int wh_flush_nolock (int timeout, wh_callback_t *cb) /* {{{ */
                         return (0);
         }
 
-        if (cb->send_buffer_fill <= 0)
+        if (cb->format == WH_FORMAT_COMMAND)
         {
-                cb->send_buffer_init_time = time (NULL);
-                return (0);
+                if (cb->send_buffer_fill <= 0)
+                {
+                        cb->send_buffer_init_time = time (NULL);
+                        return (0);
+                }
+
+                status = wh_send_buffer (cb);
+                wh_reset_buffer (cb);
         }
+        else if (cb->format == WH_FORMAT_JSON)
+        {
+                if (cb->send_buffer_fill <= 2)
+                {
+                        cb->send_buffer_init_time = time (NULL);
+                        return (0);
+                }
 
-        status = wh_send_buffer (cb);
-        wh_reset_buffer (cb);
+                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_send_buffer (cb);
+                wh_reset_buffer (cb);
+        }
+        else
+        {
+                ERROR ("write_http: wh_flush_nolock: "
+                                "Unknown format: %i",
+                                cb->format);
+                return (-1);
+        }
 
         return (status);
 } /* }}} wh_flush_nolock */
@@ -355,6 +402,60 @@ static int wh_write_command (const data_set_t *ds, const value_list_t *vl, /* {{
         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 (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_json_value_list (cb->send_buffer,
+                        &cb->send_buffer_fill,
+                        &cb->send_buffer_free,
+                        ds, vl);
+        if (status == (-ENOMEM))
+        {
+                status = wh_flush_nolock (/* timeout = */ -1, 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);
+        }
+        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, sizeof (cb->send_buffer),
+                        100.0 * ((double) cb->send_buffer_fill) / ((double) sizeof (cb->send_buffer)));
+
+        /* 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 (const data_set_t *ds, const value_list_t *vl, /* {{{ */
                 user_data_t *user_data)
 {
@@ -366,7 +467,11 @@ static int wh_write (const data_set_t *ds, const value_list_t *vl, /* {{{ */
 
         cb = user_data->data;
 
-        status = wh_write_command (ds, vl, cb);
+        if (cb->format == WH_FORMAT_JSON)
+                status = wh_write_json (ds, vl, cb);
+        else
+                status = wh_write_command (ds, vl, cb);
+
         return (status);
 } /* }}} int wh_write */
 
@@ -411,6 +516,34 @@ static int config_set_boolean (int *dest, oconfig_item_t *ci) /* {{{ */
         return (0);
 } /* }}} int config_set_boolean */
 
+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
+        {
+                ERROR ("write_http plugin: Invalid format string: %s",
+                                string);
+                return (-1);
+        }
+
+        return (0);
+} /* }}} int config_set_string */
+
 static int wh_config_url (oconfig_item_t *ci) /* {{{ */
 {
         wh_callback_t *cb;
@@ -431,6 +564,7 @@ static int wh_config_url (oconfig_item_t *ci) /* {{{ */
         cb->verify_peer = 1;
         cb->verify_host = 1;
         cb->cacert = NULL;
+        cb->format = WH_FORMAT_COMMAND;
         cb->curl = NULL;
 
         pthread_mutex_init (&cb->send_lock, /* attr = */ NULL);
@@ -453,6 +587,8 @@ static int wh_config_url (oconfig_item_t *ci) /* {{{ */
                         config_set_boolean (&cb->verify_host, child);
                 else if (strcasecmp ("CACert", child->key) == 0)
                         config_set_string (&cb->cacert, child);
+                else if (strcasecmp ("Format", child->key) == 0)
+                        config_set_format (cb, child);
                 else
                 {
                         ERROR ("write_http plugin: Invalid configuration "