From 840f4cef30b01a6928832f09daf00890b35f3582 Mon Sep 17 00:00:00 2001
From: Brandon Arp <brandon.arp@smartsheet.com>
Date: Thu, 24 Mar 2016 16:44:46 -0700
Subject: [PATCH] add http headers functionality to write_http plugin

---
 src/collectd.conf.in  |  1 +
 src/collectd.conf.pod |  6 ++++++
 src/write_http.c      | 22 +++++++++++++++++++++-
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/collectd.conf.in b/src/collectd.conf.in
index 20b17b2d..41d10ee3 100644
--- a/src/collectd.conf.in
+++ b/src/collectd.conf.in
@@ -1371,6 +1371,7 @@
 #		ClientKey "/etc/ssl/client.pem"
 #		ClientCert "/etc/ssl/client.crt"
 #		ClientKeyPass "secret"
+#		Header "X-Custom-Header: custom_value"
 #		SSLVersion "TLSv1"
 #		Format "Command"
 #		StoreRates false
diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index cf7ccd01..805fce4b 100644
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -7577,6 +7577,12 @@ authentication.
 
 Password required to load the private key in B<ClientKey>.
 
+=item B<Header> I<Header>
+
+A HTTP header to add to the request.  Multiple headers are added if this option is specified more than once.  Example:
+
+  Header "X-Custom-Header: custom_value"
+
 =item B<SSLVersion> B<SSLv2>|B<SSLv3>|B<TLSv1>|B<TLSv1_0>|B<TLSv1_1>|B<TLSv1_2>
 
 Define which SSL protocol version must be used. By default C<libcurl> will
diff --git a/src/write_http.c b/src/write_http.c
index ec3a01ce..27337813 100644
--- a/src/write_http.c
+++ b/src/write_http.c
@@ -156,7 +156,6 @@ static int wh_callback_init (wh_callback_t *cb) /* {{{ */
         curl_easy_setopt (cb->curl, CURLOPT_NOSIGNAL, 1L);
         curl_easy_setopt (cb->curl, CURLOPT_USERAGENT, COLLECTD_USERAGENT);
 
-        cb->headers = NULL;
         cb->headers = curl_slist_append (cb->headers, "Accept:  */*");
         if (cb->format == WH_FORMAT_JSON)
                 cb->headers = curl_slist_append (cb->headers, "Content-Type: application/json");
@@ -540,6 +539,25 @@ static int config_set_format (wh_callback_t *cb, /* {{{ */
         return (0);
 } /* }}} int config_set_format */
 
+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);
+  }
+
+  temp = curl_slist_append(*dest, ci->values[0].value.string);
+  if (temp == NULL)
+    return (-1);
+
+  *dest = temp;
+
+  return (0);
+} /* }}} int wh_config_append_string */
+
 static int wh_config_node (oconfig_item_t *ci) /* {{{ */
 {
         wh_callback_t *cb;
@@ -643,6 +661,8 @@ static int wh_config_node (oconfig_item_t *ci) /* {{{ */
                         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 "
-- 
2.11.0