collectd: Support configuration of write_http plugin

write_http plugin is already built and shipped in
collectd-mod-write_http, however it is not possible to configure it via
uci currently, instead having to rely on populating the config file manually.

Add support by adding 2 functions, process_write_http() and
process_write_http_node(). First one just enables/disables the plugin.
The second one, in the spirit of the curl plugin, adds support for
populating multiple <Node> elements under <Plugin write_http> with
support for a few parameters. Those are:

* name. The name of the <Node>. Mandatory
* URL. Mandatory
* Format. Optional.
* User. Optional.
* Password. Optional.
* Timeout. Optional.
* BufferSize. Optional.

Signed-off-by: Alexandros Kosiaris <akosiaris@gmail.com>

utils/collectd/files/collectd.init

@@ -78,6 +78,52 @@ process_curl_page() {
 	printf "\\t</Page>\n" >> "$COLLECTD_CONF"
 }
 
+process_write_http() {
+	printf "<Plugin write_http>\n" >> "$COLLECTD_CONF"
+	config_foreach process_write_http_node write_http_node
+	printf "</Plugin>\n\n" >> "$COLLECTD_CONF"
+}
+
+process_write_http_node() {
+	local cfg="$1"
+
+	local name URL Format User Password Timeout BufferSize
+
+	config_get name "$cfg" name
+	[ -z "$name" ] && {
+		$LOG notice "No name option in config $cfg defined"
+		return 0
+	}
+	config_get URL "$cfg" URL
+	[ -z "$URL" ] && {
+		$LOG notice "No URL option in config $cfg defined"
+		return 0
+	}
+	config_get Format "$cfg" Format
+	config_get User "$cfg" User
+	config_get Password "$cfg" Password
+	config_get Timeout "$cfg" Timeout
+	config_get BufferSize "$cfg" BufferSize
+	printf "\\t<Node \"%s\">\n" "${name}" >> "$COLLECTD_CONF"
+	printf "\\t\\tURL \"%s\"\n" "${URL}" >> "$COLLECTD_CONF"
+	[ -z "$Format" ] || {
+	       	printf "\\t\\tFormat \"%s\"\n" "${Format}" >> "$COLLECTD_CONF"
+	}
+	[ -z "$User" ] || {
+	       	printf "\\t\\tUser \"%s\"\n" "${User}" >> "$COLLECTD_CONF"
+	}
+	[ -z "$Password" ] || {
+	       	printf "\\t\\tPassword \"%s\"\n" "${Password}" >> "$COLLECTD_CONF"
+	}
+	[ -z "$Timeout" ] || {
+	       	printf "\\t\\tTimeout \%s\n" "${Timeout}" >> "$COLLECTD_CONF"
+	}
+	[ -z "$BufferSize" ] || {
+	       	printf "\\t\\tBufferSize \%s\n" "${BufferSize}" >> "$COLLECTD_CONF"
+	}
+	printf "\\t</Node>\n" >> "$COLLECTD_CONF"
+}
+
 process_network() {
 	local cfg="$1"
 
@@ -277,6 +323,10 @@ process_plugins() {
 			CONFIG_STRING=""
 			process_iptables
 			;;
+		write_http)
+			CONFIG_STRING=""
+			process_write_http
+			;;
 		*)
 			CONFIG_STRING=""
 			process_generic "$cfg" "\\t" "/usr/share/collectd/plugin/$cfg.json"

utils/collectd/files/collectd.uci

@@ -213,3 +213,10 @@ config globals 'globals'
 #config plugin 'vmem'
 #	option enable '0'
 #	option Verbose '0'
+#
+#config plugin 'write_http'
+#	option enable '0'
+#
+#config write_http_node
+#	option name 'foo'
+#	option URL 'http://example.org/post-collectd'

utils/collectd/files/usr/share/collectd/plugin/write_http.json

@@ -0,0 +1,2 @@
+{
+}