write_http: consistent multi-instance support

This makes the plugin use `<Node>` blocks liks most other write plugins,
while maintaining backwards compatibility with `<URL>` blocks.

It's a follow up to #899, which was merely a fix for the release
branches.

diff --git a/src/collectd.conf.in b/src/collectd.conf.in
index dda4fcc..62cfb77 100644 (file)
--- a/src/collectd.conf.in
+++ b/src/collectd.conf.in
@@ -1277,7 +1277,8 @@
 #</Plugin>
 
 #<Plugin write_http>
-#      <URL "http://example.com/collectd-post">
+#      <Node "example">
+#              URL "http://example.com/collectd-post"
 #              User "collectd"
 #              Password "weCh3ik0"
 #              VerifyPeer true
@@ -1291,7 +1292,7 @@
 #              Format "Command"
 #              StoreRates false
 #              BufferSize 4096
-#      </URL>
+#      </Node>
 #</Plugin>
 
 #<Plugin write_kafka>

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 12269ae..8560066 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -6954,25 +6954,29 @@ want to use authentication all three fields must be set.
 
 This output plugin submits values to an HTTP server using POST requests and
 encoding metrics with JSON or using the C<PUTVAL> command described in
-L<collectd-unixsock(5)>. Each destination you want to post data to needs to
-have one B<URL> block, within which the destination can be configured further,
-for example by specifying authentication data.
+L<collectd-unixsock(5)>.
 
 Synopsis:
 
  <Plugin "write_http">
-   <URL "http://example.com/post-collectd">
+   <Node "example">
+     URL "http://example.com/post-collectd"
      User "collectd"
      Password "weCh3ik0"
      Format JSON
-   </URL>
+   </Node>
  </Plugin>
 
-B<URL> blocks need one string argument which is used as the URL to which data
-is posted. The following options are understood within B<URL> blocks.
+The plugin can send values to multiple HTTP servers by specifying one
+E<lt>B<Node>E<nbsp>I<Name>E<gt> block for each server. Within each B<Node>
+block, the following options are available:
 
 =over 4
 
+=item B<URL> I<URL>
+
+URL to which the values are submitted to. Mandatory.
+
 =item B<User> I<Username>
 
 Optional user name needed for authentication.

diff --git a/src/write_http.c b/src/write_http.c
index 1253a26..9d8f30c 100644 (file)
--- a/src/write_http.c
+++ b/src/write_http.c
@@ -44,8 +44,9 @@
  */
 struct wh_callback_s
 {
-        char *location;
+        char *name;
 
+        char *location;
         char *user;
         char *pass;
         char *credentials;
@@ -291,6 +292,7 @@ static void wh_callback_free (void *data) /* {{{ */
                 curl_easy_cleanup (cb->curl);
                 cb->curl = NULL;
         }
+        sfree (cb->name);
         sfree (cb->location);
         sfree (cb->user);
         sfree (cb->pass);
@@ -493,7 +495,7 @@ static int config_set_format (wh_callback_t *cb, /* {{{ */
         return (0);
 } /* }}} int config_set_format */
 
-static int wh_config_url (oconfig_item_t *ci) /* {{{ */
+static int wh_config_node (oconfig_item_t *ci) /* {{{ */
 {
         wh_callback_t *cb;
         int buffer_size = 0;
@@ -515,15 +517,19 @@ static int wh_config_url (oconfig_item_t *ci) /* {{{ */
 
         pthread_mutex_init (&cb->send_lock, /* attr = */ NULL);
 
-        cf_util_get_string (ci, &cb->location);
-        if (cb->location == NULL)
-                return (-1);
+        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 (i = 0; i < ci->children_num; i++)
         {
                 oconfig_item_t *child = ci->children + i;
 
-                if (strcasecmp ("User", child->key) == 0)
+                if (strcasecmp ("URL", child->key) == 0)
+                        cf_util_get_string (child, &cb->location);
+                else if (strcasecmp ("User", child->key) == 0)
                         cf_util_get_string (child, &cb->user);
                 else if (strcasecmp ("Password", child->key) == 0)
                         cf_util_get_string (child, &cb->pass);
@@ -582,6 +588,14 @@ static int wh_config_url (oconfig_item_t *ci) /* {{{ */
                 }
         }
 
+        if (cb->location == NULL)
+        {
+                ERROR ("write_http plugin: no URL defined for instance '%s'",
+                        cb->name);
+                wh_callback_free (cb);
+                return (-1);
+        }
+
         /* Determine send_buffer_size. */
         cb->send_buffer_size = WRITE_HTTP_DEFAULT_BUFFER_SIZE;
         if (buffer_size >= 1024)
@@ -602,7 +616,7 @@ static int wh_config_url (oconfig_item_t *ci) /* {{{ */
         wh_reset_buffer (cb);
 
         ssnprintf (callback_name, sizeof (callback_name), "write_http/%s",
-                        cb->location);
+                        cb->name);
         DEBUG ("write_http: Registering write callback '%s' with URL '%s'",
                         callback_name, cb->location);
 
@@ -615,7 +629,7 @@ static int wh_config_url (oconfig_item_t *ci) /* {{{ */
         plugin_register_write (callback_name, wh_write, &user_data);
 
         return (0);
-} /* }}} int wh_config_url */
+} /* }}} int wh_config_node */
 
 static int wh_config (oconfig_item_t *ci) /* {{{ */
 {
@@ -625,8 +639,14 @@ static int wh_config (oconfig_item_t *ci) /* {{{ */
         {
                 oconfig_item_t *child = ci->children + i;
 
-                if (strcasecmp ("URL", child->key) == 0)
-                        wh_config_url (child);
+                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 "